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41-579.11B
2.5
TR RELAY
Construction:
P.C. board mounted miniature power relay.
Operation:
The TR relay is energized by the SCR at the conclusion
of the time delay. Two sets of transfer contacts are
provided to give a flexible trip circuit arrangement.
2.6
TX RELAY
Construction:
P.C. board mounted miniature power relay.
Operation:
When used (see Figure 6), the TX relay is energized by
the application of dc voltage to the relay. Because of its
slow dropout characteristic, a contact of the TX relay is
connected externally around the contact of the initiating
relay. This maintains voltage to the timing module of
the relay if the contact of the initiating relay bounces.
Discrete components (a resistor, diode, and capacitor)
are connected across the coil of the TX relay to protect
the static components from the inductive voltage kicks
associated with the coil of the TX relay. Typical operate
time for the TX relay is 7 ms. Dropout time is 15 ms.
A jumper JP1 on the printed circuit board is provided on
48/125 VDC and 24/32 VDC relays for setting the
resistance that is in series with the coil of the TX relay.
.
6
Type TD-5 Class 1E Time Delay Relay
This jumper is preset from the factory in Position 2 for
125 or 32 VDC operations. JP1 should should be set to
Position 1 in order to change setting from 125 to 48 or
from 32 to 24 VDC.
JP1 is not required on 250 VDC relays.
RELAY
RATING
POSITION
(VDC)
48/125
48/125
24/32
24/32
2.7
INDICATING CONTACTOR SWITCH (ICS)
The indicating contactor switch is a small dc 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 contacts bridge two
stationary contacts, completing the trip circuit. Also,
during this operation two fingers on the armature 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 cover.
The front spring, in addition to holding the target, provides
restraint for the armature and thus controls the pickup
value of the swtich.
For Class 1E relays, ICS units are available with 0.2,
1.0 or 2.0 amp fixed rating operating current values.
The relay nameplate identifies the value of the ICS in
the relay.
JP1
RELAY
OPERATION
(VDC)
1
48
2
125
1
24
2
32
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