Eaton NRX-Serie Montageanweisung Seite 3

Instructions for Series NRX Neutral
Current Sensor – Type NF
The grounding points of the system shall be veri ed to determine that
ground paths do not exist that would bypass the sensors. High-voltage
testers and resistance bridges may be used.
N
X
Neutral Sensor
Figure 2.
Neutral Current Sensor Application (NEMA)
N
X
Neutral Sensor
Figure 3. Neutral Current Sensor Application (IEC)
N ote: Since the ground fault circuit breakers derive their operating power from
the phase current and not from the neutral current, passing current through the
neutral sensor only will not properly test the ground fault feature.
Source
L C R
15 16
Load
Source
L C R
15 16
Load
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
circuit breaker as displayed in Figures 4 and 7. 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 indicator.
Repeat the test on the other two phases.
If the system is a 4-wire system with a neutral current sensor, apply
the same current as described above through one phase of the
breaker, returning through the neutral sensor, as displayed in Figures 5
and 8. The breaker should not trip and the alarm indicator, if supplied,
should not operate. Repeat the test on the other two phases.
If the system is a 3-wire system with no neutral current sensor, apply
the same current as described above through any two phases of the
breaker with the connections as displayed in Figures 6 and 9. 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.
Record the test results on the test form provided with the equipment.
FIELD TESTING SHOULD BE USED FOR FUNCTIONAL TESTING, NOT FOR
FIELD CALIBRATION. IF TEMPORARY CONNECTIONS WERE MADE FOR
THE PURPOSE OF CONDUCTING TESTS, RESTORE TO PROPER OPERATING
CONDITIONS BEFORE RETURNING THE BREAKER TO SERVICE.
ELECTRICAL SHOCK OR BURN INJURY CAN OCCUR WHEN WORKING ON
POWER SYSTEMS. ALWAYS TURN OFF POWER SUPPLYING CIRCUIT BREAKER
BEFORE CONDUCTING TESTS. TEST OUT OF THE CELL, IF POSSIBLE.
EATON CORPORATION www.eaton.com
IL01301032E
effective January 2011
CAUTION
WARNING
3