Section 1: Neutral Current Sensor Installation; Section 2: Performance Testing For Ground Fault Circuit Breakers - Eaton NRX Series Instruction Leaflet

Instruction Leaflet IL0131094EN
Effective March 2017

Section 1: Neutral Current Sensor Installation

Ground Fault Trip Units detect ground fault currents through Residual
Sensing. A different, round, torroidal sensor is required for source
ground or zero sequence sensing. All further information is for residual
ground fault sensing method only. If the system neutral is grounded
and residual ground fault is desired, but no phase to neutral loads are
used, a neutral current sensor is not necessary. In that case, a jumper
wire is required between circuit breaker secondary contact positions
11 and 12 (factory installed).
If the system neutral is grounded and phase to neutral loads are
used, then the neutral current sensor (see Figure 3) must be used to
account for this load in the residual ground fault sensing. It has the
same turns ratio as the phase current sensors in the Series NRX circuit
breaker. The neutral sensor is an air core design and can be used with
all Type RF I ratings (Figure 1). The factory installed jumper wire at
n
secondary contact positions 11 and 12 must be removed before
installing the neutral current sensor. See Figure 2 for installation
details.
 IMPORTANT
THE POLARITY OF THE SENSOR CONNECTIONS IS CRITICAL. ALWAYS
OBSERVE THE POLARITY MARKINGS ON THE INSTALLATION DRAWINGS.
THE POLARITY MARKINGS ARE IDENTIFIED AS WHITE DOTS ON THE
TRANSFORMERS. TO INSURE CORRECT GROUND FAULT EQUIPMENT
PERFORMANCE, CONDUCT FIELD TESTS TO COMPLY WITH NATIONAL
ELECTRIC CODE REQUIREMENTS UNDER ARTICLE 230-95-C. SEE
PERFORMANCE TESTING INSTRUCTIONS ON FOLLOWING PAGES.
70C1718G11 70C1718G12
"T" 0.787 0.750
[20] [19]
Figure 1. Dimensions.
2 EATON www.eaton.com
WHITE POLARITY
LEAD WIRE
.250
1.574
[39,98]
.144
.500 [3,64]
[12,7]
3.594
[91,29]
1.060
[26,92]
.530
[13,46]
"T"
All dimensions in inch (mm).
Series NRX with PXR - Instructions for Neutral
Section 2: Performance Testing For Ground
Fault Circuit Breakers
General Test Instructions
The interconnect system shall be evaluated in accordance with the
equipment assembler's detailed instruction by qualified personnel.
The polarity of the neutral sensor connection (if used) must agree
with equipment assembler's detailed instructions to avoid improper
operations following apparently correct simulated test operations.
Where a question exists, consult the specifying engineer and/or
equipment assembler.
The grounding points of the system shall be verified to determine
that ground paths do not exist that would bypass the sensors. High-
voltage testers and resistance bridges may be used.
.938
[23,83]
1.50
[38,1]
(3.937)
[100]
(1.063) (1.574 )
[27] [39,98]
(2.637 )
[66,98]
(3.700 )
[93,98]
Current Sensor – Type RF
1.002
[25,44]
8X ( .463 -.417)
(11.76-10.6)
3X (.984)
[24,99]
.49
[12,5]