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Caution – Rockwell Automation 140U N-Frame Circuti Breakers Instruction Leaflet for N-Frame Circuit Breakers User Manual

Page 13

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40752-093(1)

Effective 5/02

Page 13

7.3.4 Using a low voltage (0-24V), high current, AC

source, apply a test current of 125% of the ground
fault pick-up setting through one phase of the cir-
cuit breaker, as shown in Fig. 7-1a. This should
cause the breaker to trip in less than 1 second,
and if an alarm indicator is supplied, it should
operate. Reset the breaker and the alarm indica-
tor. Repeat the test on the other two phases.

7.3.5 If the system is a 4-wire system with a neutral cur-

rent sensor, apply the same current as described
in paragraph 7.3.4 above through one phase of
the breaker, returning through the neutral sensor,
as shown in Fig. 7-1b. The breaker should not trip,
and the alarm indicator, if supplied, should not
operate. Repeat the test on the other two phases.

7.3.6 If the system is a 3-wire system with no neutral

current sensor, apply the same current as
described in paragraph 7.3.4 above through any
two phases of the breaker, with the connections

exactly shown in Fig. 7-1c. The breaker should not
trip, and the alarm indicator, if supplied, should not
operate.

Repeat the test using the other two combinations of
breaker phases.

FIELD TESTING SHOULD BE USED FOR FUNC-
TIONAL TESTING AND NOT FIELD CALIBRATION.

ANY TEMPORARY CONNECTION MADE FOR THE
PURPOSE OF CONDUCTING TESTS SHOULD BE
RESTORED TO PROPER OPERATING CONDITIONS
BEFORE RETURNING THE BREAKER TO SERVICE.

7.3.7 The results of the test are to be recorded on the

test form provided with the equipment.

CAUTION

Fig. 7-1a Connections for Ground

Fault Test

Fig. 7-1b Connection for Ground

Fault No-Trip Test, with a
Four Wire System

Fig. 7-1c Connections for Ground

Fault No-Trip Test, with a
Three Wire System