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Appendix C Specifications
Overcurrent Timing Characteristics
Characteristic:
Time Dial :
Time Delay Accuracy
Instrumentation Feature
Communications Option
Power Supply
Target Indicators
Single-Phase Units:
Multi-Phase Units
Table C.1
Specifications (continued)
The relay incorporates all of the time overcurrent characteristics shown in
through
A.1 6
in
Appendix A.
accomplished by programmed instructions. Separate selections can be made for
phase current and for ground current.
Figures A.1
Refer to
through
curves for each type.
The time overcurrent delay shall be within
of the characteristic curves shown in
any combination of TIME DIAL and pickup setting at
5%
vary more than +/-
over the temperature range of
Provision is made to monitor primary current on a real-time basis. Accuracy is within
+1-
2%. Range is from 1 0% of TAP (at the low end) to 1 50% of TAP (at the high end).
Includes an RS-232 port on the front panel for local testing and configuration, and an
RS-485 port at rear of unit for operation by a Siemens Power Monitor unit at distances
up to 4000 feet using baud rates up to 1 9,200.
Power for the internal circuitry may be derived from ac or de external power sources
as indicated in
Table C.2.
hold-up circuit is required. (Option
The targets are magnetically latched type.
Current-operated targets are furnished for each of the tripping outputs included within
the relay (e.g., TIME and I NSTantaneous overcurrent functions)
To trip, a current-operated target requires a minimum of 0.2 A in the output circuit of
its associated output contact. This confirms that current has flowed through the relay
output contacts and the external trip circuit.
Includes the above plus an internally-operated target for each phase element (A,
and/or ground) which may initiate a trip.
Selection of a specific timing characteristic is
A.1 6
Appendix A,
in
which show
5%
or
20
milliseconds (whichever is greater)
Figures A.1
through
25°C.
-40°
If ac control power is used, a separate power supply
3-1)
Page 42
Figures A.1
1 4
1 00
of the
available
A.1 6
in
Appendix A
for
The time delay shall not
70°C (-40°
1 58°F)
to
to
B,
C,
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