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PowerPact H-, J-, and L-Frame Circuit Breakers
Installation Recommendations
155
02/2016
© 2011–2016 Schneider Electric
All Rights Reserved
External Neutral Voltage Tap (ENVT)
External Neutral Current Transformer (ENCT)
This connection is required for accurate power measurements on three-
pole circuit breakers equipped with Micrologic 5/6 E trip units in
installations with a distributed neutral. It can be used to measure phase-
neutral voltages and calculate power using the 3 wattmeter method.
PowerPact H-, J-, and L-frame three-pole circuit breakers come with a wire
installed on the device for the connection to the ENVT. This wire is
equipped with a connector for connection to an external wire with:
• cross-sectional area of 18–14 AWG (1 mm² to 2.5 mm²)
• maximum length of 32.8 ft. (10 m).
N A B C
I
V
ENVT
Wire
Ready for
Connection
External Wire
3P+N
External neutral voltage tap (ENVT)
This connection is required to protect the neutral on three-pole circuit
breakers equipped with Micrologic 5/6 A or E trip units in installations with a
distributed neutral. For Micrologic 6 A or E, it is required for ground-fault
protection.
The ENCT is connected in the same way for unit-mount, plug-in or drawout
devices:
• unit-mount devices are connected using terminals T1 and T2 of the
internal terminal block.
• plug-in and drawout devices are not connected using the auxiliary
terminals.
The wires must be connected/disconnected inside the devices using
terminals T1 and T2.
The ENCT must be connected to the Micrologic trip unit by a shielded
twisted pair. The shielding should be connected to the enclosure earth only
at the CT end, no more than 12 in. (30 cm) from the CT.
• the power connections of the CT to the neutral (H2 and H1) must be
made in the same way for power supply from the top or the bottom (see
figure). Make sure they are not reversed for devices with power supply
from the bottom.
• cross-sectional area of 22–16 AWG (0.4 mm² to 1.5 mm²)
• maximum length of 32.8 ft. (10 m).
N A B C
3P+N: supply from the top
I
V
ENCT
T1
T2
H2
H1
T1
T2