Energy Requirements - ABB CM Instruction Leaflet

41-181.2K
The contacts are single-pole, double throw. The
moving contact is fastened directly to the disc shaft
and the electrical connection is made thru a spiral
spring fastened to the moving contact arm and frame
assembly.
2.2. INDICATING CONTACTOR SWITCH (ICS)
The dc indicating contactor switch is a small clapper
type device. A magnetic armature, to which leaf-
spring mounted contacts are attached, is attracted to
the magnetic core upon energizing of the switch.
When the switch closes, the moving contacts bridge
two stationary contacts, completing the trip circuit.
Also during this operation two fingers on the arma-
ture deflect a spring located on the front of the
switch, allowing the operation indicator target to
drop.
The front spring, in addition to holding the target, pro-
vides restraint for the armature and thus controls the
pickup value of the switch.
2.3. AC INDICATING CONTACTOR SWITCH
(ASC)
The ac indicating contactor switch unit is a small ac
operated clapper type device. A magnetic armature,
to which leaf-spring mounted contacts are attached,
is attracted to the magnetic core upon energization of
the switch. When the switch closes, the moving con-
tacts bridge two stationary contacts completing the
trip circuit. Also, during the operation, two fingers on
the armature deflect a spring located on the front of
the switch which allows the operation indicator target
to drop.
3.0 CHARACTERISTICS
The non-tapped type CM relay has a minimum
pickup current of one ampere and a continuous ther-
mal rating of seven amperes. The tapped CM relay
has a minimum pickup of 1, 2 or 3 amperes, depend-
ing on the tap setting and a continuous of 7 amperes.
The minimum pickup current is defined as the pickup
current of each electromagnet with the other paired
electromagnet de-energized.
The relay may be utilized for continuous load cur-
rents of from one to seven amperes. The characteris-
tic curve of the relay is shown in figure 3.
4
Figure 3. Typical Operating Curve of the Type CM Relay
3.1. TRIP CIRCUIT
The main contacts will safely close 30 amperes at
250 volts dc and the seal-in contacts of the indicating
contactor switch will safely carry this current long
enough to trip a circuit breaker.
The indicating contactor switch (ICS) has two taps
that provide a pickup setting on 0.2 or 2 amperes. To
change taps requires connecting the lead located in
front of the tap block to the desired setting by means
of a screw connection.
For 0.5 ampere ACS, the 1 second coil rating is 18.0
amperes ac. For 1.0 ampere ACS, the 1 second coil
rating is 44.0 amperes ac.
3.2. TRIP CIRCUIT CONSTANTS
Contactor Switch –
ICS
0.2 ampere tap - 6.5 ohms dc resistance
2.0 ampere tap - 0.15 ohms dc resistance
ACS
0.5 ampere ACS - 18 ohms ac impedance
1.0 ampere ACS - 4.5 ohms ac impedance

4.0 ENERGY REQUIREMENTS

The burden of each electromagnet is as follows:
188A145