C74 External Cage Liquid Level Switches Instruction Manual and Parts List Description C74 external cage liquid level switches are displacer actuated units, utilizing a single switch mechanism for level alarm or control functions. These units are designed to provide high pressure/temperature capability with low specific gravity. Operating principle The design of displacer operated level switches is based upon the principle that a magnetic field will see through non-magnetic materials such as 316 stainless steel. In this case, the displacer moves a magnetic attraction sleeve within a non-magnetic enclosing tube and actuates a switch mechanism. The enclosing tube provides a pressure seal to the chamber and therefore to the process. 3 4 5 3 6 2 1 5 4 5 Figure 1 Operating cycle As the liquid level rises in the chamber, refer to Figure 1, the displacer (5) moves the magnetic attraction sleeve (1) up within the enclosing tube (4), and into the field of the switch mechanism magnet (2). As a result, the magnet is drawn in tightly to the enclosing tube causing the switch (3) to trip, making or breaking an electrical circuit. As the liquid level falls, the displacer drops and moves the attraction sleeve out of the magnetic field, releasing the switch at a predetermined low level. Refer to Figure 2. 6 5 6 2 1 4 6 4 Figure 2 Unpacking Unpack the instrument carefully. Inspect all units for damage. Report any concealed damage to carrier within 24 hours. Check the contents of the packing slip and purchase order. Check and record the serial number for future reference when ordering parts. GENERAL INFORMATION Part number construction Model identification C74 level controls are identified by a ten digit alphanumeric part numbering system. The part number provides exact specifications of unit configuration, materials of construction and other options vital to the performance of the instrument. C74- - Model number code and materials of construction Tank connection type and size Switch mechanism and enclosure MODEL number code & materials of construction Model Number Code Electric switch mechanism and enclosure Displacer Cage Attraction Sleeve C74-1 Carbon Steel 400 SST C74-2 Carbon Steel 316 SST Trim Inconel and 316 SST Tank connection type & size Connection Type Threaded Socket Weld Flanged Upper Side/Bottom Flanged Side/Side Connection Size 1" 11⁄2" 2" 300 lb. 600 lb. 300 lb. 600 lb. 300 lb. 600 lb. B70 B90 C70 C90 D70 D90 B80 B01 C80 C01 D80 D01 N40 N50 P40 P50 Q40 Q50 S40 S50 T40 T50 V40 V50 Note: Flanges are ANSI raised face. Pneumatic switch mechanism & enclosure NEMA 1 Max. Max. Bleed Switch C74-2 Supply Process Orifice Description Pressure Temp. Diameter C74-1 300 lb. 600 lb. 100 PSIG .063 JDE JDE JKE (7 Bar) (1.6 mm) Series J Bleed Type 60 PSIG 400° F .094 JEE JEE JLE (4 Bar) (204° C) (2.4 mm) Series K 100 PSIG — KOE KPE Non-Bleed (7 Bar) 2 Switch Description Max. Process One Set Temp. Point ° F (° C) Series A Mercury Switch 500 (260) Series B Snap Switch 250 (121) Series C Snap Switch 450 (232) Series D Snap Switch for DC Current Application Series E Vibration Resistant Mercury Switch Series F Hermetically Sealed Snap Switch Series HS Hermetically Sealed Snap Switch w/Wiring Leads Series HS Hermetically Sealed Snap Switch w/ Terminal Block 250 (121) 500 (260) 500 (260) 500 (260) 500 (260) NEMA 4X/7/9 SPDT DPDT SPDT DPDT SPDT DPDT Alum., Polymer Coated AKQ ANQ BKQ BNQ CKQ CNQ Alum., Cl I Div. 1 Group B AKS ANS BKS BNS CKS CNS SPDT DKQ DKS DPDT DNQ DNS SPDT EKQ EKS DPDT ENQ ENS SPDT FKQ FKS DPDT FNQ FNS SPDT HMC HEK DPDT HMF HET SPDT HM3 HM4 DPDT HM7 HM8 Consult factory for NEMA 4X/7/9 cast iron housings. Uncontrolled housing heater; drain available in NEMA 4X/7/9 enclosures. Consult factory for switch codes. Process temperature based on +100° F (+38° C) ambient. On condensing applications, temperature down-rated to +400° F (+204° C) process at +100° F (+38° C) ambient. INSTALLATION Critical alarm function Mounting 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. Adjust piping as required to bring control to a vertical position. Magnetrol controls must be mounted within three degrees (3°) of vertical. A three degree slant is noticeable by eye, but installation should be checked with a spirit level on top and/or sides of float chamber. Piping Figure 3 shows a typical piping installation of a C74 control to a pressure vessel. 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 process vessel. Controls should be mounted as close to the vessel as possible. This will result in a more responsive and accurate level change in the control. Liquid in a long line may be cooler and more dense than liquid in the vessel causing lower level indication in the control than actual level in the vessel. 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 vessel and upper vapor line will drain toward the control. Shut-off valves are recommended for installation between the vessel and the control. If control is to be used with a low temperature liquid (one which will “boil” in the float chamber if outside heat is absorbed), the chamber and piping should be insulated. Such boiling in the chamber will cause false level indications. Wiring DO NOT INSULATE SWITCH MECHANISM HOUSING. On controls equipped with pneumatic switch assemblies, consult bulletin on mechanism furnished for air (or gas) piping instructions. Refer to chart on Page 4 for bulletin numbers for pneumatic switches. CAUTION: All Series C74 units 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 supply and output connections my cause the enclosing to loosen, resulting in possible leakage if the process liquid or vapor. C74 controls are shipped with the conduit entry of the switch housing placed 180° opposite to the tank configurations to simplify installation in most cases. 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. Conduit Outlet LL Pressure Vessel HL Screw Set Screw Screw Figure 4 Shut-Off Valve Drain Valve 1. Loosen set screw(s) at base of switch housing. Refer to Figure 4. 2. Switch housing may be rotated 360° to allow correct positioning of conduit outlet. 3. Tighten set screw(s) at base of switch housing. Max. 12" Figure 3 Typical Piping Arrangement 4. Unscrew and remove switch housing cover. The threads have been lubricated to facilitate removal. 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. 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 baffle plate, and connect them to the proper terminals. Refer to the wiring diagram in your switch bulletin for this information. 3 INSTALLATION cont. Wiring cont. Switch Series Letter A B, C, D E F HS J K Wiring cont. Bulletin No. Description Standard Mercury Switch Dry Contact Switch Vibration Resistant Mercury Switch High Temperature Hermetically Sealed Snap Switch Hermetically Sealed Snap Switch Bleed Type Pneumatic Switch Non-Bleed Type Pneumatic Switch 42-683 7. Replace housing cover. 8. If control has been furnished with an explosion proof or moisture proof (gasketed) switch housing, it must be sealed at the conduit outlet with a suitable compound or non-hardening sealant to prevent entrance of air. 9. Test switch action by varying liquid level in float chamber. 42-694 42-685 42-686 NOTE: For models with a Series HS switch with high temperature lead wire, the leads are routed out through the conduit opening by the factory. A suitable conduit box should be provided for the connection of the leads to the control wiring. NOTE: If switch mechanism fails to function properly, check vertical alignment of control housing and consult installation bulletin on switch mechanism furnished. 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 housing. Internal Circuit (Left) Switch OBSERVE ALL APPLICABLE ELECTRICAL CODES AND PROPER WIRING PROCEDURES. CAUTION: In hazardous areas, do not power the unit until the conduit is sealed and the enclosure cover is screwed down securely. 1 6 3 5 6. Dress wiring to ensure no interference or contact with tilt of switch, or replacement of switch housing cover. Prevent moisture seepage into the enclosure by installing approved seal-drain fittings in the conduit run leading into the unit. 4 Close on high level Common Line Close on low level Load Load Internal Circuit (Right) Switch 2 Load Load Close on high level Common Close on low level Line Terminal Connections DPDT Switch Mechanism Series A, B, C, D, E, and F 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 capital equipment for many years. What to do 1. KEEP CONTROL CLEAN. Be sure the switch housing cover is always in place on the control. This cover is designed to keep dust and dirt from interfering with switch mechanism operation. In addition, it protects against damaging moisture and acts as a safety feature by keeping bare wires and terminals from being exposed. Should the housing cover or any seals become damaged or misplaced, obtain a replacement immediately. 2. INSPECT SWITCH MECHANISMS, TERMINALS AND CONNECTIONS MONTHLY. a. Mercury switches may be visually inspected for short circuit damage. Check for small cracks in the glass tube containing the mercury. Such cracks can allow entrance of air into the tube causing the mercury to “oxidize”. This is noticeable as the mercury will appear dirty or dull, and will not break into clean, round pools. If these conditions exist, replace the mercury switch immediately. 4 What to do cont. b. Dry contact 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. c. DO NOT operate your control with defective or maladjusted switch mechanisms (refer to bulletin on switch mechanisms furnished for service instructions.) d. Level controls may sometimes be exposed to excessive heat or moisture. Under such conditions, insulation on electrical wiring may become brittle, eventually breaking or pealing away. The resulting “bare” wires can cause short circuits. Check wiring carefully and replace at the first sign of brittle insulation. e. Vibration may sometimes cause terminal screws to work loose. Check all terminal connections to be certain that screws are tight. INSTALLATION cont. What to do cont. What to avoid 2. INSPECT SWITCH MECHANISMS, TERMINALS AND CONNECTIONS MONTHLY. CONT. 1. NEVER leave switch housing cover off the control longer than necessary to make routine inspections. f. On units with pneumatic switches, air (or gas) operating medium lines subjected to vibration, may eventually crack or become loose at connections causing leakage. Check lines and connections carefully and repair or replace, if necessary. 2. NEVER place a jumper wire across terminals to “cut-out” the control. If a “jumper” is necessary for test purposes, be certain it is removed before placing control into service. NOTE: As a matter of good practice, spare switches should be kept on hand at all times. 3. INSPECT ENTIRE UNIT PERIODICALLY. Isolate control from vessel. Raise and lower liquid level to check for switch contact and reset. 3. NEVER attempt to make adjustments or replace switches without reading instructions carefully. Certain adjustments provided for in level controls should not be attempted in the field. When in doubt, consult the factory or your local representative. 4. NEVER use lubricants on pivots of switch mechanisms. A sufficient amount of lubricant has been applied at the factory to ensure a lifetime of service. Further oiling is unnecessary and will only tend to attract dust and dirt which can interfere with mechanism operation. 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. Check switch mechanism 1. Pull disconnect switch or otherwise disconnect power to the control. 2. Remove switch housing cover. CAUTION: Unit must be normalized to atmospheric pressure before removing switch housing assembly. 3. Disconnect power wiring from switch assembly. 4. 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. 5. 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. 6. If switch magnet assembly swings freely and mechanism still fails to actuate, check installation of control to be certain it is within the specified three (3°) degrees of vertical. (Use spirit level on side of enclosing tube in two places, 90° apart. Refer to Figure 3. 7. If mechanism is equipped with a mercury switch, examine glass mercury tube closely as previously described in “Preventive Maintenance” section. If switch is damaged, replace it immediately. If microswitch, check continuity with ohmmeter. 8. If switch mechanism is operating satisfactorily, proceed to check sensing unit. Check sensing unit 1. Check to be certain liquid is entering float chamber. A valve may be closed or piping plugged. 2. With liquid in chamber, proceed to check level sensing action by removing switch housing assembly and enclosing tube. 3. Inspect attraction sleeve and inside of enclosing tube for excessive corrosion or solids build-up which could restrict movement, preventing sleeve from reaching field of magnet. 4. Never change the settings of the jam nuts which position the magnet attractor. 5. Remove parting flange. Check spring and displacer assembly for freedom of movement. Check for collapsed or liquid filled displacer. If displacer is determined to be filled or collapsed, contact the factory. Check complete unit Reassemble unit. Reconnect power supply and carefully actuate switch mechanism manually (using a non-conductive tool) to determine whether controlled equipment will operate. CAUTION: With electrical power “on”, care should be taken to avoid contact with switch leads and connections at terminal block. 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 always to specify the complete Model and Serial numbers. 5 SPECIFICATIONS 5.93 (150) 5.93 (150) 5.93 (150) 6.25 (158) D 7.94 (201) 7.94 (201) 6.25 (158) D 7.94 (201) 6.25 (158) D D D D Plugged Plugged Plugged HL HL HL C 3.78 (96) 3.78 (96) 3.78 (96) C LL LL C LL A A A B B B Vertical Flanges Upper Side/Bottom Threaded and Socket Weld Upper Side/Bottom Conn. Flange Size Rating 1" 11⁄2" 2" NPT Threaded & Socket Weld A B C 300 lb. 15.65 2.77 22.69 (601) 600 lb. (397) (70) 23.06 (585) Upper Side/ Bottom Flanges A B C 5.45 25.38 (644) (138) 25.75 (653) Horizontal Flanges Side/Side Side/Side Flanges A B C 5.45 26.0 (270) (138) 26.38 (670) 300 lb. 15.77 3.19 22.81 (579) 18.33 6.19 25.38 (644) 18.97 6.19 26.0 (270) 600 lb. (400) (81) 23.19 (589) (465) (157) 25.75 (653) (481) (157) 26.38 (670) 300 lb. 15.90 3.31 22.94 (582) 600 lb. (403) (84) 23.31 (592) 6.25 25.38 (644) (158) 25.75 (653) 6.25 26.0 (270) (158) 26.38 (670) These dimensions increase by 2.19 when used with series HS Switch w/ Terminal Block. 6 Conduit Connections D Electric Switches: NEMA 4X/7/9: 1" NPT Group B: 1" NPT Pneumatic Switches: 1 NEMA 1: ⁄4" NPT SPECIFICATIONS cont. Actuating Levels In Inches Liquid Specific Gravity Process Temperature °F (°C) 0.40 HL LL 0.50 HL LL 0.60 HL LL HL 0.70 LL HL 0.80 LL HL 0.90 LL HL 1.00 LL 100 (38) 4.38 8.24 5.56 8.74 6.35 9.07 6.92 9.31 7.34 9.49 7.67 9.63 7.94 200 (93) 4.01 7.83 5.27 8.41 6.11 8.80 6.71 9.08 7.16 9.28 7.51 9.44 7.79 9.74 9.57 300 (149) 3.59 7.36 4.94 8.04 5.83 8.49 6.47 8.81 6.95 9.05 7.32 9.24 7.62 9.39 400 (205) 3.13 6.84 4.56 7.62 5.52 8.14 6.20 8.51 6.72 8.79 7.12 9.00 7.44 9.18 500 (260) 2.61 6.26 4.15 7.15 5.18 7.75 5.91 8.18 6.46 8.50 6.89 8.75 7.23 8.94 Actuating Levels In Millimeters Liquid Specific Gravity Process Temperature °F (°C) HL LL HL LL HL LL HL LL 0.80 HL LL 0.90 HL LL 1.00 HL LL 100 (38) 111 009 141 222 161 230 176 236 186 195 202 0.40 0.50 0.60 0.70 241 245 247 200 (93) 102 199 134 214 155 224 170 231 182 236 191 240 198 243 300 (149) 91 187 125 204 148 216 164 224 177 230 186 235 194 239 400 (205) 80 174 116 194 140 207 157 216 171 223 181 229 189 233 500 (260) 66 159 105 182 132 197 150 208 164 216 175 222 184 227 3 REPLACEMENT PARTS Item Description 1 2 Housing Cover Housing Base 3 Switch Mechanism 4 Enclosing Tube 5 E-Tube Gasket Head Flange Gasket 6 7 Bolts and Nuts 8 Spring and Stem Assy. 9 Displacer Assy. 10 Chamber and Flange Assy Replacement Part Number Housing Kit Refer to bulletin on switch mechanism and housing furnished (listed on page 4). 300 lb. 600 lb. 032-6325-002 032-6325-003 012-1204-001 1 4 2 7 5 6 012-1204-019 300 lb. 600 lb. C74-1 (300 lb.) C74-1 (600 lb.) C74-2 (300 lb.) C74-2 (600 lb.) 300 lb. 600 lb. 089-3101-001 089-3102-001 089-5321-001 089-5322-001 089-5323-001 089-5324-001 089-6137-001 089-6138-001 Chamber and head flange assemblies are available by contacting the factory.When ordering specify model and serial number of control. 8 10 9 7 PRODUCT WARRANTY QUALITY ASSURANCE 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 shipment. Repair parts are warranted free of defects in materials and workmanship for one year from the date of shipment. Materials, specifications, and contents are subject to change without prior written notice. 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. 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’s quality assurance system is registered to ISO affirming its commitment to known international quality standards providing the strongest assurance of product/service quality available. 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. 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 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. LOW VOLTAGE DIRECTIVE For use in Category II installations. If equipment is used in a manner not specified by ,manufacturer, protection provided by equipment may be impaired. 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 © 2009 Magnetrol International, Incorporated. All rights reserved. Printed in the USA. BULLETIN: 46-609.3 EFFECTIVE: January 2000 SUPERSEDES: June 1996