MX or MN voltage releases are used to trip the circuit breaker. They serve primarily
for remote, emergency-off commands.
It is advised to test the system every six months.
| Power supply | V AC | 50/60 Hz: 24 – 48 – 100/130 – 200/240 |
| 50Hz: 380/415 60Hz: 208/277 | ||
| V DC | 12 – 24 – 30 – 48 – 60 – 125 -250 |
MN undervoltage release
The MN release opens the circuit breaker when its supply voltage drops to a value below 35% of its rated voltage Un.
Undervoltage tripping, combined with an emergency-off button, provides fail-safe tripping. The MN release is continuously supplied, i.e. if supply is interrupted:
·either voluntarily, by the emergency-off button,
·or accidentally, through loss of power or faulty wiring,
the release provokes opening of the circuit breaker.
Opening conditions
“Circuit-breaker tripping by an MN release meets the requirements of standard
IEC 60947-2.”
·Automatic opening of the circuit breaker is ensured when the continuous voltage supply to the release U y 0.35 x Un
·If the supply voltage is between 0.35 and 0.7 Un, opening is possible, but not guaranteed. Above 0.7 Un, opening does not take place.
Closing conditions
If there is no supply to the MN release, it is impossible to close the circuit breaker, either manually or electrically. Closing is ensured when the voltage supply to the release U u 0.85 x Un. Below this threshold, closing is not guaranteed.
MX shunt release
The MX release opens the circuit breaker via an impulse-type (u 20 ms) or maintained order.
Opening conditions
When the MX release is supplied, it automatically opens the circuit breaker. Opening is ensured for a voltage U u 0.7 x Un.
Circuit breaker control by MN or MX
When the circuit breaker has been tripped by an MN or MX release, it must be reset before it can be reclosed.
MN or MX tripping takes priority over manual closing.
“In the presence of a standing trip order, closing of the contacts, even temporary, is
not possible.”
Connection using wires up to 1.5 mm² to integrated terminal blocks.
