Magnetrol B24-1B10-CKP External cage float actuated liquid level switch Datasheet

Boiler Controls
Installation and Operating Manual
External
Cage
Float
Actuated
Liquid
Level
Switches
Read this Manual Before Installing
This manual provides information on the Boiler Controls
External Cage Liquid Level Switches. It is important that
all instructions are read carefully and followed in
sequence. Detailed instructions are included in the
Installation section of this manual.
Conventions Used in this Manual
Certain conventions are used in this manual to convey
specific types of information. General technical material,
support data, and safety information are presented in
narrative form. The following styles are used for notes,
cautions, and warnings.
Notes
Notes contain information that augments or clarifies
an operating step. Notes do not normally contain
actions. They follow the procedural steps to which
they refer.
Cautions
Cautions alert the technician to special conditions that
could injure personnel, damage equipment, or reduce
a component’s mechanical integrity. Cautions are also
used to alert the technician to unsafe practices or the
need for special protective equipment or specific
materials. In this manual, a caution indicates a
potentially hazardous situation which, if not avoided,
may result in minor or moderate injury.
Warnings
Warnings identify potentially dangerous situations or
serious hazards. In this manual, a warning indicates an
imminently hazardous situation which, if not avoided,
could result in serious injury or death.
WARNING! Explosion hazard. Do not connect or
disconnect equipment unless power has been switched off
or the area is known to be non-hazardous.
Low Voltage Directive
For use in Installation Category II, Pollution Degree 2. If
equipment is used in a manner not specified by manufacturer, protection provided by equipment may be
impaired.
Notice of Copyright and Limitations
Magnetrol, Magnetrol logotype are registered trademarks of Magnetrol International.
Copyright © 2010 Magnetrol International.
All rights reserved.
Performance specifications are effective with date of issue
and are subject to change without notice. Magnetrol
reserves the right to make changes to the product
described in this manual at any time without notice.
Magnetrol makes no warranty with respect to the accuracy
of the information in this manual.
Warranty
All Magnetrol mechanical level and flow controls are warranted free of defects in materials or workmanship for five
full years from the date of original factory shipment.
If returned within the warranty period; and, upon factory
inspection of the control, the cause of the claim is
determined to be covered under the warranty; then,
Magnetrol will repair or replace the control at no cost to
the purchaser (or owner) other than transportation.
Magnetrol shall not be liable for misapplication, labor
claims, direct or consequential damage or expense arising
from the installation or use of equipment. There are no
other warranties expressed or implied, except
special written warranties covering some Magnetrol products.
Quality assurance
The quality assurance system in place at Magnetrol
guarantees the highest level of quality throughout the
company. Magnetrol is committed to providing full
customer satisfaction both in quality products and
quality service.
Magnetrol’s quality assurance
system is registered to ISO 9001
affirming its commitment to
known international quality
standards providing the strongest
assurance of product/service
quality available.
Boiler Controls
External Cage Float Actuated
Liquid Level Switches
Table of Contents
1.0 Installation
1.1 Unpacking ................................................................4
1.2 Critical Alarm Function ............................................4
1.3 Piping .......................................................................4
1.4 Shutoff Valves for Boiler Controls.............................5
1.5 Mounting..................................................................5
1.6 Wiring ......................................................................6
2.0 Reference Information
2.1 Description ...............................................................7
2.2 Theory of Operation.................................................7
2.3 Operating Cycle ........................................................8
2.4 Switch Differential Adjustment .................................8
2.4.1 Low Level Controls ........................................9
2.4.2 High Level Controls.....................................10
2.5 Replacement of Standard Float
and Stem Assembly .................................................10
2.6 Replacement of Chamber Liner ..............................11
2.7 Tandem Float Models .............................................12
2.7.1 Installation, Preventive Maintenance,
and Troubleshooting.....................................14
2.7.2 Differential Adjustment................................14
2.7.3 Replacement of Float and Stem Assembly ....15
3.0 Troubleshooting
3.1 Check Switch Mechanism .......................................16
3.2 Check Sensing Unit ................................................16
46-630 Boiler External Cage Liquid Level Switches
4.0 Preventive Maintenance
4.1 What To Do – Every 6 Months ..............................18
4.1.1 Switch Corrosion Inspection ........................18
4.1.2 Switch and Wiring Inspection ......................19
4.1.3 Functional Test.............................................20
4.2 What To Do – Every 12 Months ............................21
4.2.1 Switch Corrosion Inspection ........................21
4.2.2 Switch and Wiring Inspection ......................22
4.2.3 Control Head Removal and Installation .......23
4.2.4 Functional Test.............................................25
5.0 Specifications
5.1 Agency Approvals....................................................26
5.2 Physical ...................................................................27
6.0 Replacement Parts
6.1 Standard Boiler Control Models .............................28
6.1.1 Parts Identification .......................................28
6.1.2 Switch and Housing Reference.....................28
6.1.3 Model B24, B25, C24, C25.........................29
6.1.4 Model W24, W25, W29, W60 ....................29
6.2 Tandem Boiler Control Models...............................30
6.2.1 Parts Identification .......................................30
6.2.2 Switch and Housing Reference.....................31
6.2.3 Model W24, W25, W29, W60 ....................31
7.0 Model Numbers.............................................................32
1.0
Installation
Caution: If equipment is used in a manner not specified by
manufacturer, protection provided by equipment may be
impaired.
1.1
Unpacking
Unpack the instrument carefully. Inspect all units for
damage. Report any concealed damage to carrier within
24 hours. Check the contents against the packing slip and
purchase order. Check and record the serial number for
future reference when ordering parts.
Caution: Do not discard the shipping container until all parts are
accounted for.
1.2
Critical alarm function
NOTE: Confirm that the installed unit meets the criteria of the intended application. The most critical parameters are the pressure,
temperature, and specific gravity. If there is a question or conflict between actual parameters and the Magnetrol switch
nameplate, contact Magnetrol for information on the level
control (please have the serial number available).
Shutoff valve
(if used)
Conduit
outlet
1.3
Switch actuating
level reference mark
Optional liquid leg
connection to vessel
Shutoff valve
(if used)
Piping
An instruction tag secured to the control gives dimensional
data on switch actuating levels referenced from center line
of upper side tank connection. Position control so that
actuating levels correspond with the desired liquid level
trip points in the boiler.
Caution: Refer to boiler manufacturer’s specifications regarding
control levels for piping alignment requirements.
Optional blow-down
or drain valve
Figure 1
Typical Piping Arrangement
It is recommended that for critical alarm functions, an
additional level switch be installed as a high–high or
low–low level alarm for maximum protection.
Use pipe of sufficient strength to support the control. If
necessary, provide a stand or hanger to help support its
weight. All piping should be straight and free of “low
spots” or “pockets” so that lower liquid line will drain
towards the boiler and upper vapor line will drain toward
the control.
Shut-off valves are recommended for installation between
the boiler and the control. Refer to Figure 1. If control is
to be used with a low temperature liquid (one which will
“boil” in the float chamber if outside heat is absorbed),
4
46-630 Boiler External Cage Liquid Level Switches
the chamber and piping should be insulated. Such boiling
in the chamber will cause false level indications.
Caution:
DO NOT INSULATE SWITCH MECHANISM
HOUSING.
For controls equipped with pneumatic switch assemblies,
consult bulletin on mechanism furnished for air (or gas)
piping instructions. See Switch and Housing Reference,
Section 6.2.2.
If the liquid to be controlled has a tendency to leave
deposits in the piping, right angle turns should be made
with cross type fittings equipped with plugs in unused
openings. Removal of plugs will permit pipe line to be
rodded clean. Blow-down connection on boiler installations should be piped in such a manner that the operator
will not scald himself when blowing down control.
1.4
Shutoff Valves for Boiler Controls
When shutoffs are used in pipe connections between boiler
and water column or boiler and shutoff valves (required
for the gauge glass), they should be either outside-screwand-yoke, level-lifting type gate valves, or stop cocks with
levers permanently fastened; or another type through-flow
shutoff valve that prevents blockage by sediment. Shutoff
valves should be locked or sealed in the open position.
When stop cocks are used, they should be the type with
the plug held in place by a guard or gland.
1.5
Mounting
Caution: This instrument is intended for use in Installation
Category II, Pollution Degree 2 locations.
Controls used on boiler applications should be mounted as
close to the boiler as possible. This will result in a more
responsive and accurate level change in the control. Water
in a long line, will be cooler and more dense than the boiler water, causing lower level indication in the control than
actual level in the boiler.
Adjust piping as required to bring control to a vertical
position. Magnetrol controls must be mounted within 3°
of vertical in all directions. A 3° slant is noticeable by eye,
but installation should be checked with a spirit level on
top and/or sides of float chamber.
Caution: Never insulate the switch housing of the level control.
46-630 Boiler External Cage Liquid Level Switches
5
Installation and maintenance of tandem float models are
accomplished in much the same manner as described for
standard models. Additional consideration must be given
to the piping arrangement to allow for alignment of the
two switch actuating level marks on the float chamber
with the desired levels in the vessel.
Caution: Operation of all buoyancy type level devices should be
done in such a way as to minimize the action of dynamic
forces on the float or displacer sensing element. Good
practice for reducing the likelihood of damage to the control is to equalize pressure across the device slowly.
1.6
Wiring
Caution: All Boiler Controls are shipped from the factory with the
enclosing tube tightened and the switch housing set
screw locked to the enclosing tube. Failure to loosen the
set screw prior to repositioning the conduit connections
may cause the enclosing tube to loosen, resulting in
possible leakage of the process liquid or vapor.
Boiler controls are shipped with the conduit entry of the
switch housing placed 180° opposite the tank connections
to simplify most installations. If this configuration is
appropriate to the installation, proceed to Step 4 to begin
wiring the unit. If another configuration is desired, the
switch housing can be easily rotated by first following
Steps 1, 2, and 3.
Screw
Screw
Set screw
Figure 2
Switch Housing Base Set Screws
NOTE: A switch or circuit breaker shall be installed in close proximity
to equipment and within easy reach of operator. It shall be
marked as the disconnecting device for equipment.
1. Loosen set screw(s) at base of switch housing. Refer to
Figure 2.
2. Switch housing may be rotated 360° to allow correct
positioning of conduit outlet.
3. Tighten set screw(s) at base of switch housing.
4. Unscrew and remove switch housing cover. The threads
have been lubricated to facilitate removal.
NOTE: For supply connections, use wire with a minimum rating of
+167° F (+75° C) as required by process conditions. Use a
minimum of 14 AWG wire for power and ground field wires.
NOTE: Housing must be grounded via protective ground screw in the
base of the housing.
NOTE: On high temperature applications (above +250° F [+121° C] in
float chamber), high temperature wire should be used
between control and first junction box located in a cooler
area. On non-hazardous applications, flexible conduit may be
used between the control and the first junction box.
5. The switch terminals are located next to the conduit outlet to facilitate wiring. Bring supply wires through conduit
outlet. Route extra wire around enclosing tube under the
6
46-630 Boiler External Cage Liquid Level Switches
baffle plate. Refer to Figure 3. Connect the supply wires to
the proper terminals. Refer to Figure 4 or your switch bulletin for this information. See Switch and Housing
Terminal block assembly
Switch
mechanism
Baffle plate
Reference, Section 6.2.2.
6. Dress wiring to ensure no interference with actuation of
switch, or replacement of switch housing cover.
Notches in
baffle plate
Run wires
under baffle
plate to terminal
block.
Conduit entry
NOTE: It is the responsibility of the customer to comply with applicable installation codes and practices. Class I, Division 1 locations may contain explosive gas mixtures. Appropriate precautions must be taken. Installation should be performed by
qualified personnel.
7. Replace housing cover.
8. If control has been furnished with an explosion proof or
moisture proof switch housing, it must be sealed at the
conduit outlet with a suitable compound or non-hardening sealant to prevent entrance of air.
Figure 3
Placement of Supply Wires
9. Test switch action by varying liquid level in float chamber.
Internal circuit
(left) switch
Line
Close on
high level
Common
Close on
low level
4
1
6
3
5
Load
Load
2
Load
Load
Internal circuit
(right) switch
Close on
high level
Common
Close on
low level
Figure 4
Terminal Connections
DPDT Switch Mechanism
Series A, B, C, D, and E
Line
NOTE: If switch mechanism fails to function properly, check vertical
alignment of control housing and consult installation bulletin
for additional wiring information on switch mechanism
furnished. See Switch and Housing Reference, Section 6.2.2.
10. Check cover to base fit to be certain gasketed joint is
tight. A positive seal is necessary to prevent infiltration of
moisture-laden air or corrosive gasses into switch
housings.
Caution: In hazardous areas, do not power the unit until the
conduit is sealed and the enclosure cover is screwed
down securely.
2.0
Reference Information
2.1
Description
Boiler controls are completely self-contained units,
designed for side mounting to a vessel or tank with
threaded or flanged pipe connections.
2.2
Theory of Operation
The design of float operated level switches is based upon
the principle that a magnetic field will not be affected by
non-magnetic materials such as 316 stainless steel. In this
case, the float moves a magnetic attraction sleeve within a
non-magnetic enclosing tube and actuates a magnetic
switch mechanism. The enclosing tube provides a pressure
seal to the chamber and therefore to the process.
46-630 Boiler External Cage Liquid Level Switches
7
Enclosing tube
(non-magnetic)
Sleeve
(magnetic)
Float
Normal
operating level
Pivot
2.3
Operating Cycle
As the liquid level rises in the chamber the float moves the
magnetic attraction sleeve up, within the enclosing tube
and into the field of the switch mechanism magnet. As a
result, the magnet is drawn in tightly to the enclosing
tube, causing the switch to trip making or breaking an
electrical circuit. Refer to Figure 5.
Tension
spring
Magnet
Swing in
position
As the liquid level falls, the float drops and moves the
attraction sleeve out of the magnetic field, releasing the
switch mechanism magnet. The tension spring ensures the
return of the switch in a snap action. Refer to Figure 6.
Figure 5
“Swing In” Magnet Position
Swing out
position
Low level
Figure 6
“Swing Out” Magnet Position
2.4
Switch Differential Adjustment
The standard differential of Boiler Control float models
with one switch (except models B24 and C24) may be
field adjusted. Adjustment may be necessary if a wider
differential needs to be set to overcome switch chatter
caused by the process.
NOTE: This procedure may be applied to single switch models only.
The differential, or the amount of level travel between
switch-on and switch-off, may be adjusted by repositioning
the lower jam nuts on the float stem. This adjustment is
different for high level and low level controls. Please refer
to the appropriate section below for adjustment instructions.
NOTE: Maximum differential adjustment is 1 inch.
Caution: Differential adjustments should NOT be made in the field
on tandem float models. Switch actuation levels have
been set at the factory to meet customer specifications.
Variations in actual conditions from design conditions,
usually require special control modifications. Consult the
factory or your local representative for assistance.
8
46-630 Boiler External Cage Liquid Level Switches
2.4.1 Low level controls
Slight play (gap)
must be allowed
(.03" [.8 mm] typical)
Position of
bottom jam nuts
(normal factory setting)
For access
to bottom
jam nuts,
remove top
jam nuts, washer,
and attracting sleeve
Sleeve stop
strap
On low level controls the switch trips on the lower
actuation point and resets on the higher actuation point.
Widening the differential will allow the switch to trip on
the original actuation point and reset at a later or higher
point.
The differential on low level controls may be adjusted by
repositioning the lower jam nuts on the float stem. The
standard factory setting is for a minimum amount of play
(gap) between the top jam nuts and the attraction sleeve.
Refer to Figure 7.
1. Determine what change in differential is necessary.
NOTE: To widen the differential by one inch, the lower jam nuts must
be set proportionately lower on the stem (i.e., in this example
by 1 inch).
Float
Figure 7
Normal Factory Setting
(minimum differential)
D
Replace in
same position
Drop bottom
jam nuts to
increase gap setting
1.00 Max gap setting
(25 mm) (Applies to models
having a single
switch mechanism
with a single magnet
actuator only)
Sleeve stop
strap
Float
Figure 8
Differential Adjustment
46-630 Boiler External Cage Liquid Level Switches
2. Make sure power source is turned off.
3. Unscrew and remove switch housing cover.
4. Disconnect power supply wires from switch mechanism.
Pull wires out of conduit connection opening in housing
base. Refer to Figure 9 on page 10.
5. Perform system shut-down procedures as required to
relieve pressure from float chamber of control. Allow unit
to cool.
6. Close shut-off valves (if so equipped) to isolate control
from tank. Drain off liquid in float chamber.
7. On installations without shut-off valves, relieve pressure
from the tank. Drain liquid in tank to a level below the
connections of the float chamber.
NOTE: Level control, connections and pipe lines need not be
removed from the tank.
8. Loosen enclosing tube nut with a 15⁄16" wrench. Unscrew
enclosing tube counterclockwise (switch and housing base
will rotate also), until it is free. Refer to Figure 9 on page 10.
9. Lift enclosing tube, switch, and base off float chamber.
Jam nuts and attraction sleeve are now accessible.
10. Measure the distance “D” from the top edge of the upper
jam nuts to the top of the float stem. Refer to Figure 8.
Record this measurement.
11. Loosen and remove upper jam nuts, guide washer and
attraction sleeve.
12. Loosen and adjust lower jam nuts to the desired position.
Tighten lower jam nuts securely. Refer to Figure 8.
13. Replace attraction sleeve on stem.
9
14. Replace upper jam nuts and guide washer on the stem in
the position previously noted. Tighten upper jam nuts
securely. Refer to Figure 8 on page 9.
Switch
housing cover
Enclosing tube
Refer to
Figures 6 and 7
Conduit
connection
Housing
base
Enclosing
tube nut
Float
Chamber
NOTE: Use a new enclosing tube gasket when reassembling enclosing tube to the chamber. Make certain that all gasket surfaces
are thoroughly cleaned to allow proper gasket seating. Coat
enclosing tube threads with anti-seizing compound.
15. Replace enclosing tube, switch, and base on chamber.
Rotate e-tube clockwise until tightened to 200–225
foot-pounds of torque.
16. Loosen the set screws at the base of the switch housing.
Rotate switch housing to correct position and tighten set
screws. Refer to Figure 2 on page 6.
Caution: After increasing gap setting, be certain to check for
proper operation of switch mechanism by raising and
lowering float assembly. Magnet must snap cleanly, with
additional float movement available after magnet snaps.
17. Bring supply wires through conduit outlet. Follow Steps 5
through 10 in Wiring, Section 1.6.
18. Test switch action by varying liquid level in float chamber.
Figure 9
NOTE: If switch mechanism fails to function properly, check vertical
alignment of control housing and consult installation bulletin
on switch mechanism. If the unit still fails to function
properly, consult the factory.
2.4.2 High level controls
On high level controls, the switch trips on the higher
actuation point and resets on the lower actuation point.
Caution: On high level controls, widening the differential requires
raising the trip point a proportional amount. The reset
point will remain the same.
To widen the differential by raising the trip point, follow
Steps 1 through 16 in Low Level Controls, Section 2.4.1.
2.5
Replacement of Standard Float
and Stem Assembly
1. Disconnect wiring or medium lines from control and perform system shutdown. See Low level controls, Section
2.4.1, steps 2 through 7.
2. Remove switch housing assembly from float chamber at
head flange by loosening flange bolting.
10
46-630 Boiler External Cage Liquid Level Switches
3. Remove sleeve stop strap from the underside of the head
flange and slide the float stem assembly out of the enclosing
tube.
Top jam
nuts
Bottom jam
nuts
Attraction
sleeve
Enclosing tube
(ref.)
Dim. A
0.03"
Minimum
gap setting
Head
flange
(ref.)
Stop tube
Sleeve
stop strap
Retaining
screws
NOTE: New float and stem kits are supplied unassembled. For standard jam nut settings (dimension A) refer to Figure 10 and
Table 1.
Table 1
Model
“A” Dimension
B24, C24
0.75 (19)
B25, C25
W24, W25, W29, W60
0.87 (22)
4. Check new float and stem assembly to be certain it is the
correct replacement unit:
4.1 Float should be of same physical size and
shape.
4.2 Stem length should match closely.
4.3 Set attraction sleeve per dimension A as shown
in Figure 10.
NOTE: If differential adjustment has been altered in the field,
disregard dimension A and readjust new assembly to the
previously determined level differential settings. See Switch
Differential Adjustment, Section 2.4.
Float and stem
assembly
Figure 10
5. Replace new float and stem assembly into head flange and
install new stop strap with screws included.
6. Remount head flange on float chamber, using new gasket
provided. Tighten flange nuts evenly, using an alternating
pattern typical of standard industry
practice.
NOTE: Care must be taken during installation to be certain float stem
does not become bent.
7. With control assembly in place, test switch actuation by
varying liquid level in float chamber.
NOTE: When reassembling the enclosing tube or the upper flange
assembly to the control, tighten according to the following
torque values in Table 2.
Table 2
46-630 Boiler External Cage Liquid Level Switches
Model
Flange Bolting
B24, B25,
C24, C25
W24, W25
35-40 ft-lbs
W29
55-60 ft-lbs
W60
150-165 ft-lbs
Enclosing Tube
200-225 ft-lbs
11
2.6
Chamber
liner
Chamber
wall recess
A
Chamber
projections
Try-cock
openings
Replacement of Chamber Liner
Models B24, B25, W24, and W25 cast float cage level
controls, specified for boiler water service, are equipped
with self-cleaning brass liners to prevent scale growth in
the chambers. Since brass has a different coefficient of
expansion than scale, any deposits that form will flake off
the liners with temperature change and be removed during
routine blow-down. Brass liners are designed to snap into a
special recess provided in the wall of the chambers.
Replacement liners are designed with a temper to spring
out against chamber wall for secure positioning.
1. Perform system shut down as required to relieve pressure
from float chamber of control and allow unit to cool.
Caution: Failure to disconnect electrical power to the unit during
maintenance may result in shock or serious injury
B
Figure 11
Chamber Liner Position
2. Disconnect wiring from supply side of switch mechanism(s)
and remove electrical conduit of operating medium line
connections to switch housing.
3. Remove switch housing, along with float and stem assembly,
by unbolting unit at head flange.
NOTE: Old liners are nearly always damaged during removal. Do not
attempt to reuse old liner.
4. With old liner removed, scrape chamber walls thoroughly
to remove all rust and scale deposits.
NOTE: New liner must fit snugly against chamber wall. Any foreign
particles between new liner and chamber will prevent a good
fit.
5. Check positioning of liner carefully before attempting to
insert into chamber.
5.1. Try-cock openings on certain water column
models are equidistant from both top and bottom of recess in chamber wall, as indicated by
reference dimensions A and B. Refer to Figure 11.
If wrong end of liner is inserted first, try-cock
openings will not line up with holes in liner.
5.2 Liner should be rotated to correct position
before inserting as it is best to avoid having to
turn liner inside the chamber.
6. To install new liner, hold with both hands and carefully
squeeze it to a diameter slightly less than the chamber
opening, with edges overlapped slightly.
7. When properly inserted, liner will spring out to fit into
recess of chamber wall.
12
46-630 Boiler External Cage Liquid Level Switches
8. Check edges of liner, which were overlapped during installation, to be certain they now butt firmly together over
entire length of liner.
9. Water column models have two projections into recess of
chamber wall. Projections must engage in notches provided
in top and bottom of liner to prevent rotation while in
service.
Caution: Unless liner edges are butted entire length, holes aligned
with chamber openings and ends engaged correctly in
chamber wall recess, liner may prevent proper float operation or obstruct water flow.
10. Reassemble control and return to service in reverse order
of steps 1 through 3. Refer to Table 2 on page 11 for
flange bolting torque specifications.
46-630 Boiler External Cage Liquid Level Switches
13
2.7
Tandem Float Models
Models with tandem floats are used on applications where
it is advantageous to have two widely spaced high and low
switching functions using a single control.
The units incorporate two floats which operate independently, and are arranged so that the lower float actuates the
upper switch mechanism, and the upper float actuates the
lower switch mechanism. The upper float is attached to
the lower attraction sleeve by means of a hollow stem. The
lower float attaches to the upper attraction sleeve with a
solid stem that extends upward, through the upper float
and stem assembly.
2.7.1 Installation, Preventive Maintenance, and
Troubleshooting
Installation and maintenance of tandem float models is
accomplished in much the same manner as for standard
models previously described. Some additional consideration must be given to the piping arrangement to allow for
alignment of the two switch actuating level marks on the
float chamber with the desired levels in the vessel. When
troubleshooting the level sensing portion of the control,
additional checks may be made of the following:
1. Inspect for binding of solid (lower) float stem within hollow
(upper) float stem due to corrosion or possible damage
incurred during shipment or blowdown.
2. Make certain that retaining (snap) rings, used to locate
lower attraction sleeve, are locked in place. An extreme
shock or hammer, such as during blow-down on a water
column boiler control, may damage a ring causing it to
snap out of its retaining groove in the hollow (upper)
float stem.
2.7.2 Differential Adjustment
Figure 12
Typical Tandem Float Control
14
Caution: No differential adjustment should be made on tandem
float models in the field. Switch actuation levels have
been set at the factory to meet customer specifications.
Variations in actual conditions, from design conditions,
usually require special control modifications.
46-630 Boiler External Cage Liquid Level Switches
2.7.3 Replacement of Float and Stem Assemblies
Top jam
nuts
Bottom jam
nuts
Attraction
sleeve
Enclosing tube
(ref.)
Dim. A
0.03"
Minimum
gap setting
Head
flange
(ref.)
Stop tube
Sleeve
stop strap
Retaining
screws
Should replacement of either upper or lower float and
stem assembly be required, see Replacement of Standard
Float and Stem Assembly, Section 2.5.
1. New float and stem assemblies are available in
separate replacement kits with attraction sleeve parts
furnished loose, to allow for field assembly with existing
serviceable components. See Replacement Parts, Section 6.0.
2. Dimension A, shown in Figure 13 must be determined by
direct measurement from old assembly.
NOTE: Disregard dimension A shown in Table 1 on page 11. If in
doubt, or unable to get an accurate measurement from old
assembly, consult factory or local representative for
assistance.
3. Lower attraction sleeve locks in place on hollow (upper)
float stem with external type snap rings.
NOTE: Care must be taken to be certain rings are properly installed.
If available, use the correct type external snap ring pliers.
3.0
Float and stem
assembly
Figure 13
Troubleshooting
Usually the first indication of improper operation is failure
of the controlled equipment to function (i.e., pump will
not start (or stop), signal lamps fail to light, etc.). When
these symptoms occur, whether at time of installation or
during routine service thereafter, check the following
potential external causes first.
Fuses may be blown.
Reset button(s) may need resetting.
Power switch may be open.
Controlled equipment may be faulty.
Wiring leading to control may be defective.
If a thorough inspection of these possible conditions fails
to locate the trouble, proceed next to a check of the
control's switch mechanism.
46-630 Boiler External Cage Liquid Level Switches
15
3.1
Check Switch Mechanism
1.
2.
3.
4.
5.
6.
7.
8.
Pull switch or otherwise disconnect power to the control.
Remove switch housing cover.
Disconnect power wiring from switch assembly.
Swing magnet assembly in and out by hand to check carefully for any sign of binding. Assembly should require
minimal force to move it through its full swing.
If binding exists, magnet may be rubbing enclosing tube.
If magnet is rubbing, loosen magnet clamp screw and shift
magnet position. Retighten magnet clamp screw.
If switch magnet assembly swings freely and mechanism
still fails to actuate, check installation of control to be
certain it is within the specified 3° of vertical.
Check switch continuity with ohmmeter. If damaged,
replace immediately.
If switch mechanism is operating satisfactorily, proceed to
check sensing unit.
NOTE: As a matter of good practice spare switches should be kept
on hand at all times.
3.2
Check Sensing Unit
1. Reconnect power supply and carefully, manually actuate
switch mechanism (use a non-conductive tool on electrical
switch mechanisms) to determine whether controlled
equipment will operate.
Shutoff valve
(if used)
Conduit
outlet
Switch
actuating
level reference
mark
Optional liquid leg
connection to vessel
Shutoff valve
(if used)
Optional blow-down
or drain valve
Figure 14
16
Caution: With electrical power on, care should be taken to avoid
contact with switch leads and connections at terminal
block.
2. If controlled equipment responds to manual actuation test,
trouble may be located in the level sensing portion of the
control, float(s), stem(s), and magnetic attraction sleeve(s).
3. Check to be certain liquid is entering float chamber.
A valve may be closed or piping plugged.
Caution: Be certain to pull disconnect switch or otherwise ensure
that electrical circuit(s) through control is deactivated.
Close operating medium supply valve on controls
equipped with pneumatic switch mechanisms.
4. Disconnect wiring from supply side of switch mechanism(s) and remove electrical conduit or operating medium
line connections to switch housing.
5. Perform system shutdown to relieve pressure from float
chamber of control, and allow unit to cool.
46-630 Boiler External Cage Liquid Level Switches
6. Close shutoff valves (if equipped) to isolate control from
vessel. Drain off liquid in chamber if necessary
7. On installations without shutoff valves, relieve pressure
from vessel and drain off liquid head above control
mounting level.
NOTE: Control chamber, connections, and pipe lines need not be
removed from vessel or boiler.
8. Remove switch housing assembly by loosening enclosing
tube hex nut, which is located immediately below housing
base. Refer to Figure 9 on page 10.
9. With switch housing assembly removed, inspect attraction
sleeve(s) and inside of enclosing tube for excessive corrosion or solids buildup, which could restrict movement,
preventing sleeve(s) from reaching field of switch magnet(s).
10. If differential has been changed in the field by repositioning the lower jam nuts on the float stem, check tightness
and position of the jam nuts.
11. Check float to be certain it is buoyant in the liquid (float
chamber or vessel must have adequate liquid level). If float
is determined to be filled with liquid, or it is collapsed, it
must be replaced immediately.
Caution:
Do not attempt to repair a float. See Replacement of
Standard Float and Stem Assembly, Section 2.5.
If all components in the control are in operating condition,
the trouble must be (and should be) located external to the
control. Repeat inspection of external conditions previously
described.
NOTE: If difficulties are encountered which cannot be identified,
consult the factory or your local representative for assistance.
A complete description of the trouble should be provided
along with information concerning your piping and mounting
arrangement, plus a description of your operating sequence.
Sketches or photographs showing the installation are also
beneficial.
When communicating about your control, be certain to
always specify the complete Model and Serial numbers.
46-630 Boiler External Cage Liquid Level Switches
17
4.0
Preventive Maintenance
Periodic inspections are a necessary means to keep your
level control in good working order. This control is a safety
device to protect the valuable equipment it serves.
Therefore, a systematic program of “preventive maintenance” must be implemented when the control is placed
into service. If the following sections on “what to do” and
“what to avoid” are observed, your control will provide
reliable protection of your equipment for many years.
4.1
What to do — every 6 months (minimum)
4.1.1 Switch Corrosion Inspection
For every 6 months in service, conduct the following
maintenance and inspection checks.
NOTE: For applications where the switches are exposed to corrosive
environments this inspection should be conducted every
3 months.
Some environments may cause accelerated corrosion on
the switch mechanism. In order to identify switch corrosion prior to failure, use the following procedures:
1. Disconnect power to the switch.
2. Remove switch housing cover to inspect switch mechanisms for visible signs of corrosion on terminals and wires.
NOTE: If cover is difficult to remove, secure base to prevent it from
moving while loosening it. Loosen set screws securing the
base to the enclosing tube prior to using a cross-bar or hammer to loosen cover. Loosening the set screws will prevent
the enclosing tube from loosening resulting in possible leaks.
3. Switches should be inspected for excessive wear on actuating lever or misalignment of adjustment screw at point of
contact between screw and lever. Such wear can cause false
switch actuating levels. Adjust switch mechanism to
compensate (if possible) or replace switch.
18
46-630 Boiler External Cage Liquid Level Switches
Adjustment
screw
Snap
switch
Terminal
screws
Switch wires
Switch
mechanism
clamping screw
Supply wires
Figure 16
4. Controls may sometimes be exposed to excessive heat or
moisture. Under such conditions, insulation on electrical
wiring may become brittle, eventually breaking or peeling
away. The resulting bare wires can cause short circuits.
Check wiring carefully and replace at the first sign of brittle insulation.
5. Vibration may sometimes cause terminal screws to work
loose. Check all terminal connections to be certain that
screws are tight.
6. Conduct a continuity test for switch contacts, using a low
voltage DC circuit with an indicator.
7. Switches that are corroded or that failed the contact continuity test should be replaced. DO NOT operate your control with defective or maladjusted switch
mechanisms (refer to bulletin on switch mechanisms
furnished for service instructions.)
8. Verify that switch housing cover and conduit seal are properly closed after each inspection of the switch mechanism(s).
NOTE: In applications with presence of salt laden air or corrosive
vapors, contact Magnetrol for possible alternate switch
mechanisms.
4.1.2 Switch and Wiring Inspection
Adjustment
screw
Switch
mechanism
clamping screw
The switch mechanism and supply wiring need to be in
proper position to assure correct switch operation.
1. Remove switch housing cover to inspect the supply wires.
2. Check that the supply wires are attached to the terminal
block and run under the baffle plate. Be certain that excess
wire does not interfere with the actuation of the switch
and that adequate clearance exists for replacement of
switch housing cover.
3. Manually push on the magnet of the switch mechanism to
confirm that the mechanism pivots freely. If it does not,
the switch mechanism should be replaced.
46-630 Boiler External Cage Liquid Level Switches
19
Snap
switch
Terminal
screws
Switch wires
Supply wires
Figure 17
Switch
mechanism
Baffle
plate
Enclosing
tube
Housing base
casting hub
Housing
base
4. Make sure the switch mechanism is seated all the way
down on the baffle plate. Refer to Figure 18. Additionally,
check that the mechanism clamping screw is tightened to
assure that the mechanism is secured to the enclosing tube
and in proper position on the baffle plate. Refer to
Figure 19. The baffle plate should rest on the housing base
casting hub.
NOTE: HS series switches use a cylindrical spacer in place of the
baffle plate. Refer to Figure 20.
5. If the above wiring conditions are not met the unit should
be rewired. Proceed to step 6.
6. Disconnect power to the switch.
Figure 18
7. The baffle plate is notched at the front and rear for control
wires to pass through. Control wires should enter through
the conduit entry, pass under the baffle plate to the notch,
then proceed through to the terminal block. Refer to
Figure 3 on page 7.
8. Control wires must not touch or interfere with the switch
or the mechanism wires. Refer to Figures 16 and 17 on
page 19 for wiring with two different terminal block configurations.
Mechanism
clamping screw
Figure 19
9. Control wires should not touch moving parts in any way.
10. The control wires should be attached to the terminal block
so that they run from the terminal block, down through
the notch, and under the baffle plate.
NOTE: The control wires must not interfere with the switch mechanism movement.
HS Switch
Mechanism
Switch
Spacer
Switch
Washer
Enclosing
Tube
Housing Base
Casting Hub
Housing
Base
Figure 20
20
11. Connect power supply to the control and conduct
functional test of unit as described below.
12. Replace switch housing cover and place control into
service.
4.1.3 Functional Test of Unit
This procedure will assure that the complete unit is
functioning properly. This test should be conducted after
switch and wiring inspections have been completed.
1. Adjust piping as required to bring control to a vertical
position. Control must be mounted within 3° of vertical.
Installation should be checked with an indicating level on
top or sides of float chamber.
46-630 Boiler External Cage Liquid Level Switches
2. Check the chamber mounting within 3° of vertical after
the boiler installation.
3. Raise level in the vessel sufficient to raise the float and trip
the switch. Lower level in the vessel sufficient to lower
float and reset the switch. Confirm switch trips and resets
at expected levels (contact Magnetrol for specific information on trip points; please have the serial number of the
unit readily available).
4.2
What to do — every 12 months (minimum)
4.2.1 Switch Corrosion Inspection
For every 12 months in service, conduct the following
maintenance and inspection checks in addition to customer specific or code requirements.
NOTE: For applications where the switches are exposed to corrosive
environments this inspection should be conducted every 3
months.
1. Disconnect power to the switch.
2. Remove switch housing cover to inspect switch mechanisms for visible signs of corrosion on terminals and wires.
NOTE: If cover is difficult to remove, secure base to prevent it from
moving while loosening it. Loosen set screws securing the
base to the enclosing tube prior to using a cross-bar or hammer to loosen cover. Loosening the set screws will prevent
the enclosing tube from loosening resulting in possible leaks.
3. Switches should be inspected for excessive wear on actuating lever or misalignment of adjustment screw at point of
contact between screw and lever. Such wear can cause false
switch actuating levels. Adjust switch mechanism to
compensate (if possible) or replace switch.
46-630 Boiler External Cage Liquid Level Switches
21
5. Controls may sometimes be exposed to excessive heat or
moisture. Under such conditions, insulation on electrical
wiring may become brittle, eventually breaking or peeling
away. The resulting bare wires can cause short circuits.
Check wiring carefully and replace at the first sign of brittle insulation.
6. Vibration may sometimes cause terminal screws to work
loose. Check all terminal connections to be certain that
screws are tight. Refer to Figure 21.
7. Conduct a continuity test for switch contacts, using a low
voltage DC circuit with an indicator.
8. Switches that are corroded or that failed the contact
continuity test should be replaced. DO NOT operate your
control with defective or maladjusted switch mechanisms
(refer to bulletin on switch mechanisms furnished for service instructions.)
9. Verify that switch housing cover and conduit seal are properly closed after each inspection of the switch mechanism(s).
NOTE: In applications with presence of salt laden air or corrosive
vapors, contact Magnetrol for possible alternate switch
mechanisms.
4.2.2 Switch and Wiring Inspection
Terminal screws
Mechanism
clamping screw
Figure 21
1.
2.
3.
4.
The switch mechanism and supply wiring need to be in
proper position to assure correct switch operation.
Remove switch housing cover to inspect the supply wires.
Check that the supply wires are attached to the terminal
block and run under the baffle plate. Refer to Figure 3 on
page 4. Be certain that excess wire does not interfere with
the actuation of the switch and that adequate clearance
exists for replacement of switch housing cover.
Manually push on the magnet of the switch mechanism to
confirm that the mechanism pivots freely. If it does not,
the switch mechanism should be replaced.
Make sure the switch mechanism is seated down on the
baffle plate. Refer to Figure 18 on page 20. Additionally,
check that the mechanism clamping screw is tightened to
assure that the mechanism is secured to the enclosing tube
and in proper position on the baffle plate. Refer to Figure
21. The baffle plate should rest on the housing base
casting hub.
Note: HS series switches use a cylindrical spacer in place of the
baffle plate. Refer to Figure 20.
22
46-630 Boiler External Cage Liquid Level Switches
Adjustment
screw
Snap
switch
Terminal
screws
NOTE: The control wires must not interfere with the switch mechanism movement.
Switch wires
Switch
mechanism
clamping screw
Supply wires
5. If the above wiring conditions are not met the unit should
be rewired. Proceed to step 6.
6. Disconnect power to the switch.
7. The baffle plate is notched at the front and rear for
control wires to pass through. Control wires should enter
through the conduit entry, pass under the baffle plate to
the notch, then proceed through to the terminal block.
Refer to Figure 3 on page 7.
8. Control wires should not touch moving parts in any way.
9. The control wires should be attached to the terminal block
so that they run from the terminal block, down through
the notch, and under the baffle plate.
Figure 22
10. Connect power supply to the control and conduct functional test of unit as described below.
11. Replace switch housing cover and place control into
service.
4.2.3 Control Head Removal and Installation
Adjustment
screw
Snap
switch
Terminal
screws
1.
2.
3.
4.
When inspection of the chamber is required the control
head must be removed to provide proper access to the
chamber. This procedure will assure that the head assembly
is removed and reinstalled properly.
Allow vessel to get to safe temperature and pressure before
opening the pressure boundary.
Power down all wiring to the unit.
Remove all wiring and conduit from the unit.
Remove flange bolts.
Switch wires
Supply wires
Switch
mechanism
clamping screw
Figure 23
46-630 Boiler External Cage Liquid Level Switches
23
5. Prepare an area where the head assembly can be placed
such that it rests on the flange in it's normal orientation
(two 2×4 boards placed across an open drum work well).
Refer to Figure 24.
6. Carefully lift the head assembly by holding the sides of the
flange. Maintain the head assembly as much as possible in
the vertical position.
NOTE: Care must be taken not to place side force on the float which
could bend the stem.
7. With the unit resting in its temporary fixture in an upright
position, it can now be inspected or repaired.
Caution: Do not place the unit on its side — this could result in
damage to the stem.
8. Conduct a check for float stem straightness as follows:
8.1 Remove the stem assembly including attraction sleeve
from the head assembly by removing the two screws
holding the stop strap to the bottom of the flange.
Refer to Figure 13 on page 15 for assembly schematic.
8.2 Check the stem straightness by aligning the stem
against a straight edge. Stems that are bent in excess of
1
⁄8 inch over any 6-inch length should not be used in
this condition. Replace any bent stems. See
Replacement Parts, Section 6.0.
Figure 24
24
46-630 Boiler External Cage Liquid Level Switches
Top jam
nuts
Bottom jam
nuts
Attraction
sleeve
Enclosing tube
(ref.)
Dim. A
0.03"
Minimum
gap setting
Head
flange
(ref.)
Stop tube
Sleeve
stop strap
Retaining
screws
8.3 Ensure that the components in the stem assembly are
in good condition and surfaces are clear of potential
obstructions. The stem assembly is reinstalled by
securing the stop strap to the flange. Ensure that the
attraction sleeve moves freely through the enclosing
tube and that the stem assembly surfaces are smooth.
Note: Care must be taken during the straightness check to be certain that the attraction sleeve is not removed from the stem
and jam nuts settings are not changed.
9. Raise the liquid level in the container that the unit is set
on sufficient to lift the float and trip the switch mechanism. Inspect inside of chamber for any obstructions or
scale buildup. If excessive buildup is present, the interval
between inspections should be shortened. Remove old gasket such that mating flange surfaces are completely clean.
Position new gasket on chamber flange before replacing
the head assembly.
Note: The float is restricted from moving laterally by the chamber, in
the test configuration the float and stem can move further off
center than possible under normal operation. Avoid excess
movement in this lateral direction during the test. If switch
trips, the unit may be reassembled. If not, follow the procedure
in Troubleshooting, Section 3.0.
Float and stem
assembly
Figure 25
10. Replace the assembly keeping it as vertical as possible.
Carefully lower the assembly into the chamber making
sure that the stem does not become bent during installation. Refer to Figure 24.
11. Tighten flange bolts per torque values in Table 2 on page 11.
12. Attach wiring and connect power supply as described in
Switch and Wiring Inspection, Section 4.2.2.
4.2.4 Functional Test of Unit
This procedure will assure that the complete unit is
functioning properly. This test should be conducted after
switch and wiring inspections have been completed.
1. Adjust piping as required to bring control to a vertical
position. Control must be mounted within 3° of vertical.
Installation should be checked with an indicating level on
top or sides of float chamber.
2. Check the chamber mounting within 3° of vertical after
the boiler installation.
3. Raise level in the vessel sufficient to raise the float and trip
the switch. Lower level in the vessel sufficient to lower
float and reset the switch. Confirm switch trips and resets
at expected levels (contact Magnetrol for specific information on trip points; please have the serial number of the
unit readily available).
46-630 Boiler External Cage Liquid Level Switches
25
5.0
Specifications
5.1
Agency Approvals
AGENCY
APPROVED MODEL
APPROVAL CLASSES
FM
All with an electric switch mechanism and a housing
listed as TYPE 4X/7/9
Class I, Div 1, Groups C & D
Class II, Div 1, Groups E, F & G
All with an electric switch mechanism and a housing
listed as TYPE 4X/7/9 Class I, Div 1, Group B
Class I, Div 1, Groups B, C & D
Class II, Div 1, Groups E, F & G
All with a Series HS, H1, F, 8 or 9 electric switch
mechanism and a housing listed as CSA TYPE 4X
Class I, Div 2, Groups B, C & D
All with an electric switch mechanism and a housing
listed as TYPE 4X/7/9
Class I, Div 1, Groups C & D
Class II, Div 1, Groups E, F & G
All with an electric switch mechanism and a housing
listed as TYPE 4X/7/9 Class I, Div 1, Group B
Class I, Div 1, Groups B, C & D
Class II, Div 1, Groups E, F & G
All with an electric switch mechanism and an
ATEX housing ATEX II 2 G EEx d IIC T6
94/9/EC
IEC Ex Ex d IIC T6
IP 66
Low Voltage Directives 2006/95/EC
Per Harmonized Standard:
EN 61010-1/1993 & Amendment No.
Installation Category II
Pollution Degree 2
CSA
ATEX / IEC Ex CE
Dual stage units with “HS” or “H1” switches are not ATEX approved.
IEC Installation Instructions:
The cable entry and closing devices shall be Ex d certified suitable for the conditions of use
and correctly installed.
For ambient temperatures above +55° C or for process temperatures above +150° C, suitable
heat resistant cables shall be used.
Heat extensions (between process connection and housing) shall never be insulated.
Special conditions for safe use:
When the equipment is installed in process temperatures higher than +85° C the temperature
classification must be reduced according to the following table as per IEC60079-0.
Maximum Process
Temperature
Temperature
Classification
< 85° C
T6
< 100° C
T5
< 135° C
T4
< 200° C
T3
< 300° C
T2
< 450° C
T1
These units are in conformity with IECEx KEM 05.0020X
Classification Ex d IIC T6
Tambient -40° C to +70° C
26
46-630 Boiler External Cage Liquid Level Switches
5.2
Physical
Inches (mm)
N
P
P
N
N
P
Q
Q
M
plugged
M
M
M
plugged
HL
LL
M
Drum
connections
K
Gauge
glass L
tappings
R
Q
M
plugged
R
K
K
LL
HL
I
K
LL
T
Try cock
tappings
G
K
C
Models B24, C24
A
I
C
A
R
A
Low water
cutoff point
HL
B
S
J
Models B25, C25
Allow 10.00 (254) overhead clearance
for cover removal.
ACTUATION LEVELS *
L
K
E
B
Model
D
Conduit Connections M
S
C
B24/C24
Models W24, W25, W29, W60
B25/C25
Electrical Switches:
NEMA 4X/7/9: 1" NPT
Group B:
1" NPT
Pneumatic Switches:
1
NEMA 1:
⁄4" NPT
W24
W25
W29
All housings rotatable 360°
W60
B24/C24
B25/C25
W24
W25
W29
W60
A
5.56
(141)
7.00
(177)
16.00
(405)
13.50
(343)
15.00
(381)
15.00
(381)
0.69
(18)
3.69
(94)
11.38
(289)
9.44
(240)
11.00
(279)
10.50
(267)
1.56
(40)
4.50
(114)
12.25
(311)
10.25
(260)
11.88
(302)
11.06
(281)
1.0
HL
LL
0.94
(24)
4.13
(105)
11.88
(302)
9.88
(251)
11.50
(292)
11.19
(284)
1.69
(42)
4.88
(124)
12.63
(321)
10.63
(270)
12.25
(311)
11.69
(297)
* Single switch mechanism only. Consult factory
for multiple switches.
Levels are ± 0.25" (6 mm)
DIMENSIONS
Model
Min. S.G.
HL
LL
B
n/a
2.00
(51)
3.00
(76)
2.00
(51)
4.50
(114)
4.19
(106)
C
2.81
(71)
2.63
(66)
2.63
(66)
2.63
(66)
2.83
(71)
3.61
(91)
D
E
G
I
J
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
3.06
(77)
3.06
(77)
2.88
(73)
3.66
(92)
3.50
(88)
2.00
(51)
4.50
(114)
4.19
(106)
15.00
(381)
13.50
(343)
15.00
(381)
15.00
(381)
3.50
(88)
3.00
(76)
3.50
(88)
3.50
(88)
4.00
(101)
3.00
(76)
4.00
(101)
4.00
(101)
46-630 Boiler External Cage Liquid Level Switches
K
1"
NPT
1"
NPT
11⁄4"
NPT
1"
NPT
11⁄4"
NPT
11⁄4"
NPT
L
n/a
n/a
⁄4"
NPT
1
⁄2"
NPT
3
⁄4"
NPT
3
⁄4"
NPT
3
N
P
Q
R
5.93
(150)
5.93
(150)
5.93
(150)
5.93
(150)
5.93
(150)
5.93
(150)
3.78
(96)
3.78
(96)
3.78
(96)
3.78
(96)
3.78
(96)
3.78
(96)
6.25
(158)
8.46
(214)
8.46
(214)
8.46
(214)
8.46
(214)
8.46
(214)
16.25
(412)
22.12
(561)
33.50
(850)
28.62
(726)
33.50
(850)
34.37
(872)
S
T
n/a
n/a
1 ⁄4"
NPT
3
⁄4"
NPT
11⁄4"
NPT
3
⁄4"
NPT
3
⁄4"
NPT
1
n/a
3
⁄4"
NPT
1
⁄2"
NPT
3
⁄4"
NPT
3
⁄4"
NPT
27
6.0
Replacement Parts
6.1
Standard Boiler Control Models
6.1.1 Parts Identification
1
3
16
2
17
6
9
11
10
18
4
14
15
5
8
6
12
7
9
10
13
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Housing cover
Housing base
Switch mechanism
Enclosing tube
Enclosing tube gasket
Head flange
Studs and bolts
Hex nuts
Flange gasket
Float chamber
Stop strap
Screws
Float and stem assembly
Jam nuts
Guide washer
Attraction sleeve
Stop tube
Chamber liner
IMPORTANT:
When ordering, please specify:
A. Model and serial number of control.
B. Replacement assembly (kit) part number.
6.1.2 Switch and housing reference
Dry contact
High Temperature
Hermetically sealed
Bleed type pneumatic
Non-bleed type pneumatic
28
Series Type
B, C, D
F, R, 8, 9
HS
J
K
Bulletin#
42-683
42-799
42-694
42-685
42-686
46-630 Boiler External Cage Liquid Level Switches
6.1.3 Models B24, C24, B25, and C25 B24
C24
Housing cover
See at left
Housing base
See at left
Switch mechanism
See at left
Enclosing tube kit
089-5933-001
includes items 4 and 5
Enclosing tube gasket
012-1204-001
Head flange kit
089-4201-001
includes items 5, 6, 7, 8, and 9
Flange gasket
012-1301-003
089-4601-001
Float chamber kit includes items 7, 8, 9, 10, and 18
Float and stem assembly
089-3201-001
includes items 9, 11, 12, 13, 14, 15, 16, and 17
005-5524-001
not required
Chamber liner Complete control
089-6564-003
B25
C25 See at left
See at left
See at left
089-5933-004
012-1204-001
089-4202-001
012-1301-003
089-4602-002
089-4602-001
089-3245-001
089-3202-001
005-5518-001
089-6565-004
not required
089-6565-003 W29
W60
less float chamber (10), bolts (7), nuts (8), and liner (18)
6.1.4 Models W24, W25, W29 and W60 W24
W25
Housing cover
See at left
Housing base
See at left
Switch mechanism
See at left
Enclosing tube kit
089-5933-004
includes items 4 and 5
Enclosing tube gasket
012-1204-001
Head flange kit
089-4202-001
includes items 5, 6, 7, 8, and 9
Flange gasket
012-1301-003
089-4608-001
089-4607-001
Float chamber kit includes items 7, 8, 9, 10, and 18
Float and stem assembly
089-3211-001
089-3210-001
includes items 9, 11, 12, 13, 14, 15, 16, and 17
005-5520-001
005-5522-001
Chamber liner Complete control
089-6566-005
089-6566-004
See at left
See at left
See at left
089-5933-004
012-1204-001
089-4203-001
089-4206-002
012-1301-025
089-4609-001
012-1301-024
089-4610-001
089-3212-001
089-3213-001
not required
089-6566-006
not available
less float chamber (10), bolts (7), nuts (8), and liner (18)
Notes:
All replacement assemblies listed are furnished in kit form for standard base models. Consult local representative
for ordering assistance on all special model replacement parts or accessories not included in above listing.
Model and serial numbers required.
Cast float cage models used on boiler service require brass chamber liner.
Consult factory for replacement parts for models with material of construction code -2.
46-630 Boiler External Cage Liquid Level Switches
29
6.2
Tandem Boiler Control Models
6.2.1 Parts Identification
16
3
17
14
15
2
13
1
4
6
9
5
8
11
7
10
12
19
20
30
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Housing cover
Housing base
Switch mechanism
Enclosing tube
Enclosing tube gasket
Head flange
Studs and bolts
Hex nuts
Flange gasket
Stop strap
Screws
Upper float and stem assembly
Lower attraction sleeve
Spacer washer
Retaining ring
Jam nuts
Upper attraction sleeve
Lower float and stem assembly
Safety stop washer
Float chamber
Chamber liner (not shown)
IMPORTANT:
When ordering, please specify:
A. Model and serial number of control.
B. Replacement assembly (kit) part number.
18
46-630 Boiler External Cage Liquid Level Switches
6.2.2 Switch and housing reference
Dry contact
High Temperature
Hermetically sealed
Bleed type pneumatic
Non-bleed type pneumatic
Series Type
B, C, D
F, R, 8, 9
HS
J
K
Bulletin#
42-683
42-799
42-694
42-685
42-686
6.2.3 Models W24, W25, W29 and W60 W24 W25 Housing cover
See above
Housing base
See above
Switch mechanism
See above
Enclosing tube kit
089-5909-001
includes items 4 and 5
Enclosing tube gasket
012-1204-001
Head flange kit
089-4202-001
includes items 5, 6, 7, 8, and 9
Flange gasket
012-1301-003
Float chamber kit
089-4608-001
089-4607-001
includes items 7, 8, 9, 20, and 21
Upper float and stem assembly
089-3225-001
089-3224-001
includes items 9, 10, 11, 12, 13, 14, and 15
Lower float and stem assembly
089-3214-001
includes items 9, 16, 17, 18, and 19
Chamber liner
005-5520-001
005-5522-001
W29
W60
See above
See above
See above
089-5909-001
089-5933-004
012-1204-001
089-4203-001
089-4206-002
012-1301-025
089-4609-001
012-1301-024
089-4610-001
089-3217-001
see note 089-3216-001
see note not required
Notes:
All replacement assemblies listed are furnished in kit form for standard base models. Consult local representative
for ordering assistance on all special model replacement parts or accessories not included in above listing.
Model and serial numbers required.
Cast float cage models used on boiler service require brass chamber liner.
Special order item. Specify model and serial number when ordering.
46-630 Boiler External Cage Liquid Level Switches
31
7.0
Model Numbers
MODEL NUMBER CODE, MATERIALS OF CONSTRUCTION AND TANK CONNECTION
Model
Code
B24-1B10 C24-1B10 B25-1B10 C25-1B10 C25-2B10 W24-1B10 Minimum
S.G.
Maximum
WSP Chamber
Material
250 psig
Cast Iron 0.85
0.84
0.84
250 psig
Cast Iron Cast Iron W25-1B10 0.84
250 psig
W29-1B10
0.84
300 psig
W60-1B10
0.75
600 psig
Fabricated
Steel
Attraction
Sleeve
Float
Material
Trim
Material
Max. WSP
Rating
316L SS
316 SS
250 psi @ 406° F
(17 bar @ 207° C)
400 Series
SS
Max. Pressure Try Cock
@ 100° F (38° C) Mounting
400 psi
(28 bar)
N/A
316 SS
400 Series
SS
400 Series
SS
Right
Hand
316L SS
316 SS
300 psi @ 422° F
(21 bar @ 217° C)
500 psi
(34 bar)
600 psi @ 489° F
(41 bar @ 254° C)
900 psi
(62 bar)
Left
Hand
ELECTRIC SWITCH MECHANISM AND ENCLOSURE Max. Process
Temp.
° F (° C) Contacts
Switch
Description
250
Series B
Snap Switch
(121)
450
Series C
Snap Switch
(232)
Series F
Hermetically Sealed
Snap Switch
750
(399)
B24 & C24 only
Set
Points
NEMA 4X/7/9 Aluminum Enclosure Class I, Div. 1,
Class I, Div. 1,
Groups C & D
Group B
SPDT
1
BKP
BKT
DPDT
1
BNP
BNT
SPDT
1
CKP
CKT
DPDT
1
CNP
CNT
SPDT
1
FKP
FKT
DPDT
1
FNP
FNT
PNEUMATIC SWITCH MECHANISM AND ENCLOSURE
Switch Description
Series J Bleed Type
Series K Non-Bleed Type
Maximum
Supply Pressure
psig
bar
100
60
100
40
Cast iron models limited to maximum service temperature
of +406° F (+207° C) or switch mechanism temperature
rating if lower.
Saturated steam service rating
Models B24, B25, W24, and W25 contain brass inner liners.
Models C24 & C25 are intended for non-boiler service as
they do not contain a chamber liner.
32
7
4
7
3
Maximum
Process Temp.
°F
°C
400
400
400
400
204
204
204
204
Bleed Orifice
Diameter
Inches
mm
.063
.094
—
—
1.6
2.3
—
—
All except
B24, C24
NEMA 1
Code
B24, C24
NEMA 1
JDE
JEE
KOE
KOG
—
JEG
—
KOG
Process temperature based on +100° F (+38° C) ambient
Uncontrolled housing heater or drain available in NEMA 4X/7/9.
Consult factory for standard part numbers.
Consult factory for NEMA 4X/7/9 cast iron housings.
Consult factory for manual reset switches.
On steam and other condensing applications, temperature downrated to +400° F (+204° C) process at +100° F (+38° C) ambient.
46-630 Boiler External Cage Liquid Level Switches
ELECTRIC SWITCH MECHANISM AND ENCLOSURE Switch Description
Series B
Snap Switch
Series C
Snap Switch
Series D DC Current
Snap Switch
Series F
Hermetically Sealed
Snap Switch
Series HS
Hermetically Sealed
5-amp Snap Switch
with Wiring Leads
All models except
Model C25-2B10 only
B24, C24 and C25-2B10
Process Temperature
Set
TYPE 4X/7/9 Aluminum Enclosure
Contacts
Range
Points
ATEX
ATEX
Class I, Div 1 Class I, Div 1
Class I, Div 1 Class I, Div 1
°F (°C)
Ex II 2 G EEx
Ex II 2 G EEx
Groups C&D
Group B
Groups C&D
Group B
d IIC T6
d IIC T6
BKA
BKJ
BCC
BKB
BKK
BC9
1
2
BLA
BLJ
BDC
BLB
BLK
BD9
SPDT
-40 to +250
3
BMA
BMJ
BEC
BMB
BMK
BE9
(-40 to +121)
1
BNA
BNJ
BFC
BNB
BNK
BF9
DPDT
2
BOA
BOJ
BGC
BOB
BOK
BG9
1
CKA
CKJ
CCC
CKB
CKK
CC9
SPDT
2
CLA
CLJ
CDC
CLB
CLK
CD9
-40 to +450
3
CMA
CMJ
CEC
CMB
CMK
CE9
(-40 to +232)
1
CNA
CNJ
CFC
CNB
CNK
CF9
DPDT
2
COA
COJ
CGC
COB
COK
CG9
1
DKB
DKK
DC9
SPDT
2
DLB
DLK
DD9
-40 to +250
3
N/A
DMB
DMK
DE9
(-40 to +121)
1
DNB
DNK
DF9
DPDT
2
DOB
DOK
DG9
1
FKA
FKJ
FCC
FKB
FKK
FC9
SPDT
2
FLA
FLJ
FDC
FLB
FLK
FD9
-50 to +750
(-46 to +399)
1
FNA
FNJ
FFC
FNB
FNK
FF9
DPDT
2
FOA
FOJ
FGC
FOB
FOK
FG9
1
HMJ
HMK
SPDT
2
HMN
HMP
-50 to +550
N/A
N/A
(-46 to +288)
1
HMS
HMT
DPDT
2
HMY
HMZ
Series HS
Hermetically Sealed
5-amp Snap Switch
with Terminal Block
-50 to +550
(-46 to +288)
Series H1
Hermetically Sealed
1-amp Snap Switch
with Wiring Leads
-50 to +750
(-46 to +399)
Series R
High Temperature
Snap Switch
-40 to +750
(-40 to +399)
Series 8
Hermetically Sealed
Snap Switch
-50 to +750
(-46 to +399)
Series 9
High Temperature
Hermetically Sealed
Snap Switch
-50 to +750
(-46 to +399)
Switch Description
Series R
High Temperature
Snap Switch
Series 9
High Temperature
Hermetically Sealed
Snap Switch
SPDT
1
HM3
HM4
HA9
HM7
HM8
HB9
HKJ
HKK
HKN
HKP
RKB
RLB
RNB
ROB
8KB
8LB
8MB
8NB
8OB
9KB
9LB
9MB
9NB
9OB
RKK
RLK
RNK
ROK
8KK
8LK
8MK
8NK
8OK
9KK
9LK
9MK
9NK
9OK
N/A
DPDT
1
SPDT
1
N/A
DPDT
SPDT
DPDT
SPDT
DPDT
SPDT
DPDT
N/A
2
1
2
1
2
1
2
3
1
2
1
2
3
1
2
N/A
8KA
8LA
8MA
8NA
8OA
9KA
9LA
9MA
9NA
9OA
8KJ
8LJ
8MJ
8NJ
8OJ
9KJ
9LJ
9MJ
9NJ
9OJ
8CC
8DC
8EC
8FC
8GC
9CC
9DC
9EC
9FC
9GC
RC9
RD9
RF9
RG9
8C9
8D9
8E9
8F9
8G9
9C9
9D9
9E9
9F9
9G9
Process Cast Iron
Cast Iron
CS/Aluminum
CS/Aluminum
Set
Temp. Range Contacts
Points NEMA 4X Class I, Div 1 Class I, Div 1 NEMA 4X Class I, Div 1 Class I, Div 1
°F (°C)
Groups C&D
Group B
Groups C&D
Group B
1
R1M
RKM
RKW
SPDT
2
R3M
RLM
RLW
-40 to +1000
N/A
(-40 to +538)
1
RDM
RNM
RNW
DPDT
2
REM
ROM
ROW
1
9AD
9KD
9KV
9AM
9KM
9KW
SPDT
2
9BD
9LD
9LV
9BM
9LM
9LW
-50 to +1000
3
9CD
9MD
9MV
9CM
9MM
9MW
(-46 to +538)
1
9DD
9ND
9NV
9DM
9NM
9NW
DPDT
2
9ED
9OD
9OV
9EM
9OM
9OW
46-630 Boiler External Cage Liquid Level Switches
33
Notes
34
46-630 Boiler External Cage Liquid Level Switches
Notes
46-630 Boiler External Cage Liquid Level Switches
35
ASSURED QUALITY & SERVICE COST LESS
Service Policy
Return Material Procedure
Owners of Magnetrol may request the return of a control
or any part of a control for complete rebuilding or
replacement. They will be rebuilt or replaced promptly.
Controls returned under our service policy must be
returned by Prepaid transportation. Magnetrol will repair
or replace the control at no cost to the purchaser (or
owner) other than transportation if:
So that we may efficiently process any materials that are
returned, it is essential that a “Return Material
Authorization” (RMA) number be obtained from the factory, prior to the material's return. This is available
through Magnetrol’s local representative or by contacting
the factory. Please supply the following information:
1. Returned within the warranty period; and
2. The factory inspection finds the cause of the claim
to be covered under the warranty.
If the trouble is the result of conditions beyond our control; or, is NOT covered by the warranty, there will be
charges for labor and the parts required to rebuild or
replace the equipment.
In some cases it may be expedient to ship replacement
parts; or, in extreme cases a complete new control, to
replace the original equipment before it is returned. If
this is desired, notify the factory of both the model and
serial numbers of the control to be replaced. In such
cases, credit for the materials returned will be determined
on the basis of the applicability of our warranty.
1.
2.
3.
4.
5.
Company Name
Description of Material
Serial Number
Reason for Return
Application
Any unit that was used in a process must be properly
cleaned in accordance with OSHA standards, before it is
returned to the factory.
A Material Safety Data Sheet (MSDS) must accompany
material that was used in any media.
All shipments returned to the factory must be by prepaid
transportation.
All replacements will be shipped F.O.B. factory.
No claims for misapplication, labor, direct or consequential damage will be allowed.
5300 Belmont Road • Downers Grove, Illinois 60515-4499 • 630-969-4000 • Fax 630-969-9489 • www.magnetrol.com
145 Jardin Drive, Units 1 & 2 • Concord, Ontario Canada L4K 1X7 • 905-738-9600 • Fax 905-738-1306
Heikensstraat 6 • B 9240 Zele, Belgium • 052 45.11.11 • Fax 052 45.09.93
Regent Business Ctr., Jubilee Rd. • Burgess Hill, Sussex RH15 9TL U.K. • 01444-871313 • Fax 01444-871317
Copyright © 2010 Magnetrol International, Incorporated. All rights reserved. Printed in the USA.
BULLETIN: 46-630.2
EFFECTIVE: August 2010
SUPERSEDES: January 2009