Load categories

S/GEN/APPLICATIONS/A/08/01/2002
page 1/ 5 GB
APPLICATION OF SOLID STATE RELAYS
1- Most frequent types of loads :
Reference to IEC/EN 947-x-x standards
Proud to serve you
All technical characteristics are subject to change without previous notice.
Caractéristiques sujettes à modifications sans préavis.
celduc
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S/GEN/APPLICATIONS/A/08/01/2002
page 2/ 5 GB
Type of
current
Category
of use
Characteristics
applications
non-inductive
AC-51
loads or
hardly inductive
resistance furnaces,....
alternating
current
AC-53
POWER
AC-4
AC-55a
Squirrel cage
motors :
starting, switching
motors started
Squirrel cage motors :
starting, reversal
of operation,
single stroke
operation
Control of
discharge lamps
Precautions for use
For on-off relays, use zero cross relays. In the case
of heating elements with wound resistor, the switched current can
be up to 1.4 times the assigned current.
Refer to the selection guides AC-51 : solutions in single phase,
two phase and three phase
Use proportional full wave pulse control relays for the
variation in power : control in 0-10V or 4-20mA.
The starting currents can reach 8 times the assigned current
for a duration of 1.6 seconds. The relays specified in AC-53
account for these surges. Voltage surges generated by
the motor can appear on opening of the relay.
celduc proposes on/off control products (SVT , SGT)
and SOFT-START starters ( SMCW).
Refer to the selection guides AC-53.
The stresses are quick close to the applications in AC-53, however
with even greater surges on the reversal.
Performing reversals of the rotation direction with solid state relays
calls for very high immunity products, a control logic
integrating a locking of controls and a
time delay on each reversal.
celduc proposes suitable products : SG9/SV9/SW9
Refer to the selection guides : AC-53 and AC-4.
-->Fluorescent lamps without power factor corrector
(AC-55a) carry currents which can reach twice the
assigned current for a short instant.
--> Parallel compensated fluorescent lamps (AC-56b) ,
can carry inrush current 20 times the assigned current and
generator significant surges on opening.
--> Electronic ballast fluorescent lamps can have
current peaks 10 times the assigned current.
--> High pressure mercury vapour lamps and metallic
halogenide lamps without power factor corrector are
switched via ballast units of the serial inductance type and
using arcing devices. During the starting period,
a mainly inductive current is made. As this current can be
twice the assigned current, it must be supported by the
solid state relay (AC-55a)
--> High pressure sodium vapour lamps also carry
an inductive current from 1.7 to 2.2 times the assigned current.
--> High pressure mercury vapour lamps and metallic
halogenide and sodium vapour lamps with power corrector
factor carry significant capacitive inrush currents and
generate surges on opening AC-56b).
The general rule is to use the zero cross relays adapted to
the current surges (warning : to check the resistance of these
repetitive currents --> see the curve : repetitive Itsm = f(t) )
AC-55a = 10 In for 20ms / 6In for 200ms /
3In for 10 s / 2In for 1 minute
AC-56b = 30 In for 20ms / 1.4In for 200ms /
1,1In for 1 s : see §AC56b (capacitor batteries)
and voltage surges on opening using relays of 400VAC
on the 230VAC network.

celduc
www.celduc.com
r e l a i s
Rue Ampère B.P. 4
42290 SORBIERS - FRANCE
E-Mail : [email protected]
Fax +33 (0) 4 77 53 85 51
Service Commercial France Tél. : +33 (0) 4 77 53 90 20
Sales Dept.For Europe Tel. : +33 (0) 4 77 53 90 21 Sales Dept. Asia : Tél. +33 (0) 4 77 53 90 19
S/GEN/APPLICATIONS/A/08/01/2002
page 3/ 5 GB
Type of
current
Category
of use
Characteristic
applications
AC-55b
Control of
incandescent
lamps
alternati
ng
current
POWER
AC-56a
Control of
transformers
capacitor
batteries
AC-7b
The cold starting of an incandescent lamp produces significant
current surges. The filaments of these lamps have very low resistances
cold, it is advantageous to zero cross switch them.
The current surge is reduced which greatly increases the
lifetime of the lamp.
The general rule is to use zero cross relays adapted to the
current surges (repetitive):
AC55b = 10 In for 20ms / 6In for 200ms / 1.2In
for 1 s / 1.1In for 10 s
At the end of the lifetime of these lamps, short-circuits between coils can
produce strong current surges which can be considered as short-circuits.
The coordination between the semiconductor relay and the
device for protection against short-circuits must be accounted for.
For the variation in power of these loads, it is also possible to use
random relays with an adapted control or relays (SG4)
allowing for the variation of the PHASE ANGLE (CONTROLLER)
according to an isolated 0-10V or 4-20mA analog input.
This is a special type of control of the load. The saturation
of the magnetic circuit must be avoided.
If a conventional solid state relay is used, it must be oversized.
The magnetising current of a transformer can reach 100 times
the nominal current.
Use oversized random relays or special transformer control
relays : special application note.
Mainly power factor correctors but also loads with
filters by capacitor at the input (see certain discharge
lamps). Mainly 2 problems :
--> current surge on closing
--> voltage surge on opening
celduc has developed a range of relays dedicated to these
applications with high Itsm (up to 20 000 A/20ms and 1600 volts)
with a special application note
AC-56b Control of
AC-7a
Précautions of use
Control of slightly
inductive loads for
household appliances and
similar applications
Motor for
domestic
applications
Same specifications as AC-51 adhering to the current and
voltage limits of the relays.
Single phase motor with collector or universal motors.
Preferably use random relays. The brushes generate
microcuts generating voltage surges. It is highly
advised to protect the relay by a varistor.
The variation in speed of these motors can be performed
with SG4 type CONTROLLER relays.
Asynchronous single phase motor with capacitor
These motors are used in a great deal of
mechanisms requiring a change of the
rotation direction.
The control is provided by two alternatively
M
switched relays for each
change of rotation.
R
celduc
C

www.celduc.com
r e l a i s
Rue Ampère B.P. 4
42290 SORBIERS - FRANCE
E-Mail : [email protected]
Fax +33 (0) 4 77 53 85 51
Service Commercial France Tél. : +33 (0) 4 77 53 90 20
Sales Dept.For Europe Tel. : +33 (0) 4 77 53 90 21 Sales Dept. Asia : Tél. +33 (0) 4 77 53 90 19
S/GEN/APPLICATIONS/A/08/01/2002
page 4/ 5 GB
Type of
current
Category
of use
Characteristic
applications
AC-7b
( suite)
Motors for
domestic
applications
AC-8
(a et b)
Control of
hermetic
refrigeration
compressors
alternating
current
POWER
other
loads
AC-12
alternating
current
INTERFACE
Précautions of use
Asynchronous single phase motors with capacity (contd.)
The relays must be controlled with a short time delay (50
to 100ms ) to ensure the breaking of one before the other.
In the case of simultaneous operation, provide for a serial
resistor R with dephasing capacitor. The value of this resistor must
be: Vmax capacitor/ Itsm of relay. Provide a wound power
resistor P= R x Inominal motor x Inominal motor.
It is also to be pointed out that the voltage across the terminals of
the open relay the voltage across the terminals of the capacitor C.
This is typically ϖ2 times the mains voltage and can be greater
if the voltages on the windings are not exactly quadrature .
Consequently, use 400VAC relays on 230V network.
It is also possible to vary the speed of these asynchronous
single phase motors by adjusting the slipping, i.e. the
power supply voltage. SG4 type CONTROLLER relays
can be used. However, precautions must be taken with
regard to heating of these motors. Please consult us.
Quite similar to a start in AC-53 , with starting currents
capable of reaching 8 to 10 times the assigned current.
Refer to the AC-53 currents allowing for a small
extra margin.
DC loads supplied from an alternating mains
DC loads suppied
from an AC mains
This type of load has the
inconvenience of switching
a practically rectangular
current which may be a
DC
problem for relays
AC
using standard triacs.
The celduc relays are
fully suited to this type of
load by oversizing the
current of the relay with that of the maximum peak current of the load.
Control of ohmic
loads and loads
insulated by
optocoupler
current
Ohmic load : refer to the characteristics in AC-51.
Loads insulated by optocoupler.
example : Solid state relay pilot controlling another alternating control
solid state relay capable of operating with 1.5mA (eg : regulators which
pilot control a solid state relay). You must make sure that the leakage
current in blocked state of relay N°1 does not allow for the control of
relay N°2 .
A parallel impedance on the input of relay N°2 may be
required to ensure a voltage lower than the non-operating voltage of
the relay.
24 or 230VAC
RELAY N°1
PH
RELAY N°2
R
N
24 or 230VAC
celduc
ALTERNATIVE INPUT
RELAY

www.celduc.com
r e l a i s
Rue Ampère B.P. 4
42290 SORBIERS - FRANCE
E-Mail : [email protected]
Fax +33 (0) 4 77 53 85 51
Service Commercial France Tél. : +33 (0) 4 77 53 90 20
Sales Dept.For Europe Tel. : +33 (0) 4 77 53 90 21 Sales Dept. Asia : Tél. +33 (0) 4 77 53 90 19
S/GEN/APPLICATIONS/A/08/01/2002
page 5/ 5 GB
Type of
current
Category
of use
Characteristic
applications
AC-13
Control of static
loads insulated by
transformers
AC-14
alternative
current
INTERFACE
AC-15
direct
current
DC-1
DC-12
Control of
electromagnetic
loads
(contactors, etc)
Low loads :
< 72VA
Control of
electromagnetic
loads (contactors, etc)
High loads : > 72 VA
non inductive or
hardly inductive loads,
resistor furnaces, etc.
control of ohmic
loads or static loads
insulated by photocoupler
DC-13 control
of electromagnets
control
DC-14 of electromagnets
with economy resistors
DC-3
DC-5
DC-6
Précautions of use
Check the compatibility with the magnetising current of the
transformer.
This is typically the case for solenoid valves, contactor
control coils, small servocontrol motors, etc.
Although it is preferable to use random relays, the
celduc zero cross relays are fully suited to this type
of load.
Solid state relays with a reduced leakage current must be
used to avoid these loads being kept supplied in the
blocked state. The celduc interface relays are very well
suited to this type of load.
Oversize if there is a risk of saturation of the load and
preferably use random relays. The celduc zero cross
relays are also suitable.
In DC , as in AC , the rules are as follows :
--> Adhere to the currents and voltages.
--> account for inrush currents of the different loads
( DC-3 ; DC-5 ; DC-6 )
--> Account for any voltage surges ==> Place a free
wheel diode on the inductive loads ( DC-13 ;
DC-14 ; DC-3 ; DC-5)
Use the following relays of the celduc range :
* SKD 3A 60VDC / 1A 200VDC control 3-30VDC
* XKD 3A 60VDC / 1A 200VDC control 3-30VDC or
models with control in AC
* SCC 5A 60VDC /15A 60VDC
* SGC 20A 200VDC
* SGD 30 and 60A in 50 and 100VDC
shunt motors :
starting, reversal, etc
serial motors :
starting and reversal
Control of
incandescent
lamps
celduc

www.celduc.com
r e l a i s
Rue Ampère B.P. 4
42290 SORBIERS - FRANCE
E-Mail : [email protected]
Fax +33 (0) 4 77 53 85 51
Service Commercial France Tél. : +33 (0) 4 77 53 90 20
Sales Dept.For Europe Tel. : +33 (0) 4 77 53 90 21 Sales Dept. Asia : Tél. +33 (0) 4 77 53 90 19