Brochure
PowerPact H-, J-, and L-Frame Circuit Breakers
Trip Units
87
02/2016
© 2011–2016 Schneider Electric
All Rights Reserved
Micrologic 3 Trip Units
Micrologic 3 trip units can be used on PowerPact H-, J-, and L-Frame circuit breakers with performance
levels D/G/J/L.
They provide:
•
standard protection of distribution cables
•
indication of:
— overloads (using LEDs)
— overload tripping (using the SDx relay module)
Circuit breakers equipped with Micrologic 3 trip units can be used to protect distribution systems
supplied by transformers.
Protection
Settings are made using the adjustment rotary switches.
Overloads: Long time protection (I
r
)
Inverse time protection against overloads with an adjustable current pick-up I
r
set using a rotary switch
and an adjustable time delay t
r
.
Neutral protection
•
On three-pole L-frame circuit breakers, neutral protection is not possible.
•
On four-pole L-frame circuit breakers, neutral protection may be set using a three-position switch:
— switch position 4P 3D: neutral unprotected
— switch position 4P 3D + N/2: neutral protection at half the value of the phase pick-up, (0.5 x I
r
)
— switch position 4P 4D: neutral fully protected at I
r
Indicators
Front indicators
•
The green “Ready” LED blinks slowly when the electronic trip unit is ready to provide protection. It
indicates the trip unit is operating correctly.
•
Orange overload pre-alarm LED: steady on when I > 90% I
r
•
Red overload LED: steady on when I > 105% I
r
Remote indicators
An overload trip signal can be remotely checked by installing an SDx relay module inside the circuit
breaker. This module receives the signal from the Micrologic electronic trip unit through an optical link
and makes it available on the terminal block. The signal is cleared when the circuit breaker is reclosed.
See page 120.
Ii
tr
Ir
3.2
Ir (A) tr @ 6 Ir
Ii (x In)
15
60
50
45
40
35
30
25
20
.5
16
16
16
8
4
2
1
1.5
15
12
10
8
6
4
3
2
450 16
16
8
4
2
16
.5
150
175
200
350
125
300
250
225
12
8
4
5
3
110
1.5
2
6
Ir (A)
Ii (x In)Tr @ 6 Ir
Ii
x
SDX Module
Front Indicators