I.L. 41-759.2D
2
ARS Relay
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 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, which allows the operation indicator target to
drop. The target is reset from the outside of the case
by a push-rod located at the bottom of the case.
The front spring, in addition to holding the target, pro-
vides restraint for the armature and thus controls the
pickup value of the switch.
The ICS is commonly used to provide a seal in
around the main protective relay contacts relieving
them of carrying heavy duty trip currents. When ac
current is necessary in a control trip circuit, some
chattering can be observed and the ICS unit can be
replaced by and ACS unit.
3.0
CHARACTERISTICS
All ARS relays are capable of being energized con-
tinuously. The energy requirements are listed in
Table 1.
AR Unit
All AR units are capable of being energized continu-
ously. All high speed relays will pick up at 80% of
rated voltage or less; and drop out at 5% of rated
voltage or higher.
Typical operating times and effective contact bounce
are outlined in Tables 2 and 4.
Each relay contact is rated 3 amps continuous and
30 amps long enough to trip a breaker.
Indicating Contactor Switch (ICS)
The main contacts will close 30 amperes at 250 Vdc
and the seal-in contacts of the indicating contactor
switch (ICS) will carry this current long enough to trip
a circuit breaker.
The indicating contactor switch (ICS) has two taps
that provide a pickup setting of 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. Operating speed of the ICS
unit at two times pickup is 10 to 16 ms.
ARS Operate and Reset Time
The operate and reset times for the ARS relay are
shown in Tables 2 and 3. The ARS operating time is
the combined time of the circuit delay time (Table 3)
plus the AR unit time (Table 2) according to the par-
ticular contact arrangement used.
Table 1:
Input Energy Requirements
Per Input
INPUT
(dc Volts)
INPUT
VOLTAGE
RANGE
(dc Volts)
MAXIMUM
INPUT
CURRENT
REQUIREMENT
20
15 to 20
6 milliamperes
Drain Per AR Unit
dc Volts
Non-Operate
Operate
48
0
83 milliamperes
125
0
210 milliamperes
Trip Circuit Constants
Indicating Contactor Switch
0.2 A tap
6.5 ohms dc resistance
2.0 A tap
0.15 ohms dc resistance
Table 2:
AR Unit Operate and Reset Times
Rated
Operating
Energy
(Watts)
Operate Time
(Milliseconds)
Reset Time
(Milliseconds)
NO
Contact
Closes
NC
Contact
Opens
NC Contact
Closes
10
2.0
1.5
4.0
