Brochure

PowerPact H-, J-, and L-Frame Circuit Breakers
Accessories for Micrologic™ Trip Units
113
02/2016
© 2011–2016 Schneider Electric
All Rights Reserved
External Neutral Current Transformer (ENCT)
The external neutral current transformer is a sensor required for a three-pole circuit breaker in a
system with a distributed neutral to measure the neutral current in order to:
• protect the neutral conductor
• protect against ground faults.
This current transformer can be connected to Micrologic 5/6 trip units. The transformer rating must be
compatible with that of the circuit breaker.
For installation recommendations, see page 155.
External Neutral Voltage Tap (ENVT)
The external neutral voltage tap is required for Micrologic E power metering with a three-pole circuit
breaker in a system with a distributed neutral. It is used to connect the neutral to the Micrologic trip unit
to measure phase-to-neutral (Ph-N) voltages.
The ENVT is included with the Micrologic 5/6 electronic trip unit.
Zone Selective Interlock (ZSI) Module
A ZSI terminal block may be used to interconnect a number of Micrologic trip units to provide zone
selective interlocking for short-time (I
sd
) and ground-fault (I
g
) protection, without a time delay. For
PowerPact H- and J-frame circuit breakers, the ZSI function is available only in relation to the
upstream circuit breaker (ZSI out). For PowerPact L-frame circuit breakers, the ZSI function is
available in relation to the upstream circuit breaker (ZSI out) and downstream circuit breakers (ZSI in).
External neutral current
transformer
Table 83: Current Transformers
Circuit Breaker Rating Catalog No.
H-Frame
60–100 A S429521
150 A S430562
J-Frame 250 A S430563
L-Frame 400–600 A S432575
External Neutral
Voltage Tap
Table 84: ZSI Catalog Number
Description Catalog No.
ZSI Module S434212