Frequently asked questions

FA234591

28 September 2021

Product Line:
NT and NW Masterpact breaker

Resolution:
 
 Table 41:        T-Frame Circuit Breakers
External neutral sensor for 3-phase, 4-wire residual ground fault system (or for neutral current monitoring).
These neutral sensors include their wiring harness. To order this harness as a spare part, order cat. no. NCTWIRING. 
 

NT Circuit Breaker Sensor Plug

External Neutral Sensor for general use

External Neutral Sensor Square D Panelboard

External Neutral Sensor for use in Square D Switchboards

  External neutral sensor for circuit breakers with standard neutral protection

100–250 A	S33575	S33924	S33926
400–1600 A	S33576	S33925	S33927

  External neutral sensor for circuit breakers with oversized neutral protection♦

100 A	S33575	S33924	S33926
250 A	N/A	N/A	N/A
400–1000 A	S33576	S33925	S33927
1200/1250 A	S48896	N/A	NA
1600 A	S48182	N/A	NA

♦Oversized neutral protection = 1.6xIr where Ir = long time pick-up.


Table 42:        W/Y-Frame Circuit Breakers
External neutral sensor for 3-phase, 4-wire residual ground fault system (or for neutral current monitoring) and external sensor for Modified Differential Ground Fault (MDGF) or Source Ground Return (SGR) system.
These neutral sensors include their wiring harness. To order this harness as a spare part, order cat. no. NCTWIRING.
 

Frame Size	Sensor Plug (A)	External Neutral Sensor		PZ4 External Neutral Sensor (For use in PZ4 Switchgear)		MDGF/ SGR Sensor►
		For Residual Ground Fault	For 3-Pole Circuit Breaker with Oversize Neutral Protection♦	For Residual Ground Fault	For 3-Pole Circuit Breaker with Oversize Neutral Protection♦
W	100	S48916	S48916	S48902	S48902
	250		N/A		N/A
	400	S34036	S34036	S48903	S48903	S33579
	600/630
	800
	1000
	1200/1250		S48896
	1600		S48182		N/A
	2000	S48896
	2500	S48182		S48182
	3000		N/A
	3200
	4000					N/A
Y	2000	S48897•	S48897•	S48898•	S48898•	S33579
	2500
	3000				N/A
	3200
	4000
	5000		N/A	S48897•
	6000
	6300			N/A

•Kit includes qty. (2) neutral sensors.
►Four MDGF sensors (phase + 1 neutral) are required for W-frame; eight MDGF sensors are required for Y-frame. For SGR system, only one sensor (neutral) is required for W-frame; two sensors for Y-Frame.
        An MDGF/SGR ground fault interface module (Cat. no. S48891) is also required for each circuit breaker. 
♦Oversized neutral protection = 1.6xIr where Ir = long time pick-up.

See catalog 0613DB1607 for more Masterpact parts