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A-72
Electrical and mechanical
accessories
Compact NS1600b to 3200
(cont.)
Compact NS1600b to 3200 circuit breakers may be
equipped with an MX shunt release, an MN
undervoltage release or a delayed undervoltage
release (MNR = MN + delay unit).
Remote tripping
This function opens the circuit breaker via an electrical order. It is made up of:
a shunt release 2
b
nd
MX
or an undervoltage release MN
b
or a delayed undervoltage release MNR = MN + delay unit.
b
These releases (2
nd
MX or MN) cannot be operated by the communication bus.
The delay unit, installed outside the circuit breaker, may be disabled by an
emergency OFF button to obtain instantaneous opening of the circuit breaker.
Wiring diagram for the remote-tripping function
Voltage releases 2
nd
MX
When energised, the 2
nd
MX voltage release instantaneously opens the circuit
breaker. A continuous supply of power to the 2
nd
MX locks the circuit breaker in the
OFF position.
Functions and characteristics
Characteristics
Power supply V AC 50/60 Hz 24 - 48 - 100/130 - 200/250 - 277 - 380/480
V DC
12 - 24/30 - 48/60 - 100/130 - 200/250
Operating threshold
0.7 to 1.1 Un
Permanent locking function
0.85 to 1.1 Un
Consumption (VA or W)
pick-up: 200 (80 ms)
hold: 4.5
Circuit breaker response
50 ms±10
time at Un
Instantaneous voltage releases MN
The MN release instantaneously opens the circuit breaker when its supply voltage
drops to a value between 35 % and 70 % of its rated voltage. If there is no supply on
the release, it is impossible to close the circuit breaker, either manually or electrically.
Any attempt to close the circuit breaker has no effect on the main contacts. Circuit
breaker closing is enabled again when the supply voltage of the release returns to 85
% of its rated value.
Characteristics
Power supply V AC 50/60 Hz 24 - 48 - 100/130 - 200/250 - 380/480
V DC
24/30 - 48/60 - 100/130 - 200/250
Operating
opening
0.35 to 0.7 Un
threshold
closing
0.85 Un
Consumption (VA or W)
pick-up: 200 (200 ms)
hold: 4.5
MN consumption
pick-up: 400 (200 ms)
hold: 4.5
with delay unit (VA or W)
Circuit breaker response
90 ms±5
time at Un
MN delay units
To eliminate circuit breaker nuisance tripping during short voltage dips, operation of
the MN release can be delayed. This function is achieved by adding an external
delay unit in the MN voltage-release circuit. Two versions are available, adjustable
and non-adjustable.
Characteristics
Power supply
non-adjustable
100/130 - 200/250
V AC 50-60 Hz /DC
adjustable
48/60 - 100/130 - 200/250 - 380/480
Operating threshold
opening
0.35 to 0.7 Un
closing
0.85 Un
Consumption of delay
pick-up: 200 (200 ms)
hold: 4.5
unit alone (VA or W)
Circuit breaker response
non-adjustable
0.25 s
time at Un
adjustable
0.5 s - 0.9 s - 1.5 s - 3 s
DB128138
Opening
order
D2
D1
MN
DB128137
C2
C1
MX
Opening
order
DB128139
MN
D2
D1
10 12
3 6
Delayed
opening
order
Instantaneous
opening
order
Delay
unit
056421
MX voltage release