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Each unit closes its contacts after a time de
lay which is dependent both on the ratio and the
magnitudes of the currents and also on the time
lever setting. The time decreases with an increase
of both currents or an increase of the ratio of ope�
ating to restraint current. The time lever controls
the contact travel. A lower time lever setting de
creases the contact travel and the time.
RATINGS
Present available ratings are 5 amperes nor
mal current
up, with 120";t> slope.
The current-closing rating of the contacts is
30 amperes for voltages not exceeding 250 volts.
The current-carrying ratings are affected by the
selection of the tap on the target and seal-in coil
as indicated in the following table:
Function
Tripping Duty
Carry Continuously
The 2-ampere tap has a d-e resistance of 0.13
ohms and a 60 cycle impedance of 0.53 ohms while
the 0.2-ampere tap has a 7 ohm d-e resistance and
a 52 ohm 60 cycle impedance. The tap setting used
RECEIVING, HANDLING AND STORAGE
These relays, when not included as a part of
a control panel, will be shipped in cartons designed
to protect them against damage. Immediately upon
receipt of the relay, an examination should be made
for any damage sustained during shipment.
jury or damage resulting from rough handling is
evident, a claim should be filed at once with t h e
transportation company and the nearest Sales Office
of the General Electric Company notified promptly.
Reasonable care should be exercised in unpack-
LOCATION
The location should be clean and dry, free from
dust and excessive vibration, and well lighted to
facilitate inspection and testing.
MOUNTING
The relay should be mounted on a vertical sur
face. The outline and panel diagrams a r e shown
in Figs. 8 and 9.
CONNECTIONS
Internal connections are shown in Figs. 6 and 7.
Typical external connections for t h e UC52A
relay, are shown in Fig. 5.
30
5
0.8
4
If
in
INSTALLATION
Current Balance Relays
on the seal-in element is determined by the current
drawn by the trip coil.
The 0.2-ampere tap is for use with trip coils
that operate on currents ranging from 0.2 up to 2.0
amperes at the minimum control voltage.
tap is used with trip coils requiring more than 2
amperes, there is a possibility that the 7-ohm re
sistance will reduce the current to so low a value
that the breaker will not be tripped.
The 2-ampere tap should be used with trip coils
that take 2 amperes or more at minimum control
ceed
amperes at the maximum control voltage.
If
the tripping current exceeds 30 amperes an aux
iliary relay should be used, the connections being
such that the tripping current does not pass through
the contacts or the target and seal-in coils of the
protective relay.
BURDENS
The burdens imposed on the current transform
ers by each operating and restraining coil at 5 amps
are as follows:
Circuit
Ohms
Oper:tting
.38
Restraints
.54
ing the relay in order that none of the parts are in
jured or the adjustments disturbed.
If
the relays are not to be installed immediate
ly, they should be stored in their original cartons
in a place that is free from moisture, dust, and
metallic chips.
Foreign matter collected on the
outside of the case may find its way insidewhen the
cover is removed and cause trouble in the operation
of the relay.
When the exciting winding of the transformer
is connected in grounded wye, the secondaries of
the current transformers in series with this wind
ing should be delta-connected to avoid tripping ()n
external ground faults.
GROUND CONNECTIONS
One of the mounting studs or screws should be
&
S gage copper wire or its equivalent.
INSPECTION
At the time of installation, the relay should be
inspected for tarnished contacts, loose screws, or
If
other imperfections
should be corrected in the manner described under
"Maintenance".
Types IJC
·If
this
Power
Volt
Factor
9.5
.38
.34
13.5
any trouble i s found, it
5
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