Phase S/C; Phase /C - GE 239 Instruction Manual

CHAPTER 4: PROGRAMMING
CURVE
NUMBER
1.03 1.05
10 14369 8537
11 15806 9391
12 17243 10245
13 18680 11098
14 20116 11952
15 21553 12806
4.5.2

Phase S/C

239 MOTOR PROTECTION RELAY – INSTRUCTION MANUAL
Courtesy of NationalSwitchgear.com
Table 4–2: 239 Phase Overload Trip Times (Seconds)
MULTIPLE OF MOTOR FULL LOAD CURRENT
1.1 1.5 2 2.5
4166.8 699.9 291.6 166.6
4583.5 769.9 320.7 183.3
5000.2 839.9 349.9 199.9
5416.9 909.9 379.1 216.6
5833.5 979.9 408.2 233.2
6250.2 1049.8 437.4 249.9
• PHASE S/C TRIP: In any application where the available short circuit current is above
the interrupting capability of the contactor, short circuit currents must cause a fuse or
circuit breaker to operate. This prevents damage to the contactor which is not designed
to interrupt normal levels of short circuit current. In an application with fuses, program
the setpoint
S4: PROTECTION\PHASE CURRENT\PHASE S/C\PHASE S\C TRIP: OFF
prevent the contactor from attempting to trip during a short circuit.
If a circuit breaker which can be tripped by an external contact closure is available
upstream from the contactor, it is possible to program the setpoint
PROTECTION\PHASE CURRENT\PHASE S/C\PHASE S\C TRIP: AUXILIARY
short circuit to activate the auxiliary relay instead of the trip relay. Though, it is also
possible to activate both the trip & auxiliary relays simultaneously. The auxiliary relay
could then be connected to the upstream breaker to cause it to open for a short
circuit. Ensure that the auxiliary relay is only programmed to activate under short
circuit when used in this manner.
SPECIAL NOTE: The AUXILIARY and TRIP status indicators will both operate for these
trips even if the TRIP relay is not selected for use (i.e. AUXILIARY). If the breaker cannot
be externally tripped, program the setpoint
S/C\PHASE S\C TRIP: OFF
short circuit. If a breaker is used as the motor starter interrupting device, short circuit
protection would generally be enabled as it will normally be capable of handling the
fault current. Short circuit protection causes the breaker to open quickly to prevent
excessive mechanical damage or fire due to any large phase current. Complete
protection from phase-to-phase and phase-to-ground faults is provided with this
feature. When enabled, by programming setpoint
CURRENT\PHASE S/C\PHASE S\C TRIP: TRIP
times, including during motor starts. It can be disabled by setting the setpoint
PROTECTION\PHASE CURRENT\PHASE S/C\PHASE S\C TRIP: OFF
• PHASE S/C PICKUP: The phase current short circuit trip level can be set from 1 to 11
times the phase CT primary. When any phase current meets or exceeds this setpoint
value during start or run conditions and is maintained for the
setpoint, the selected relay(s) will activate.
3 4 5
109.3 58.3 36.43 24.98
120.3 64.1 40.08 27.48
131.2 70.0 43.72 29.98
142.1 75.8 47.36 32.48
153.0 81.6 51.01 34.97
164.0 87.4 54.65 37.47
S4: PROTECTION\PHASE CURRENT\PHASE
to prevent the contactor from attempting to trip during a
S4: PROTECTION\PHASE
, short circuit protection is active at all
6 8 10 11
13.88 8.83 7.29
15.27 9.71 8.01
16.65 10.60 8.74
18.04 11.48 9.47
19.43 12.36 10.20
20.82 13.25 10.93
to
S4:
to cause a
S4:
.
PHASE S/C DELAY
4–35