97 / 248
A-83
Remote tripping
MX or MN voltage releases are used to trip the circuit breaker. They serve primarily
for remote, emergency-off commands.
,W LV DGYLVHG WR WHVW WKH V\VWHP HYHU\ VL[ PRQWKV
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,
b
or accidentally, through loss of power or faulty wiring,
b
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
b
supply to the release U
y
[ 8Q
If the supply voltage is between 0.35 and 0.7 Un, opening is possible, but not
b
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
[ 8Q %HORZ WKLV WKUHVKROG FORVLQJ LV QRW JXDUDQWHHG
Characteristics
Power supply
V AC
50/60 Hz: 24 - 48 - 100/130 - 200/240
50 Hz: 380/415 60 Hz: 208/277
V DC
12 - 24 - 30 - 48 - 60 - 125 -250
Operating threshold
Opening
0.35 to 0.7 Un
Closing
0.85 Un
Operating range
0.85 to 1.1 Un
Consumption (VA or W)
Pick-up: 30 - Hold: 5
Response time (ms)
50
Time-delay unit for an MN release
A time delay unit for the MN release eliminates the risk of nuisance tripping due to a
transient voltage dip lasting
y
200 ms. For shorter micro-outages, a system of
capacitors provides temporary supply to the MN at U > 0.7 to ensure non tripping.
The correspondence between MN releases and time-delay units is shown below.
Power supply
Corresponding MN release
8QLW ZLWK ¿[HG GHOD\ PV
48 V AC
48 V DC
220 / 240 V AC
250 V DC
Unit with adjustable delay
y
PV
48 - 60 V AC/DC
48 V DC
100 - 130 V AC/DC
125 V DC
220 - 250 V AC/DC
250 V DC
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
[ 8Q
Characteristics
Power supply
V AC
50/60 Hz: 24 - 48 - 100/130 - 200/240
50 Hz: 380/415 60 Hz: 208/277
V DC
12 - 24 - 30 - 48 - 60 - 125 -250
Operating range
0.7 to 1.1 Un
Consumption (VA or W)
Pick-up: 30
Response time (ms)
50
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.
b
Note:
circuit breaker opening using an MN or MX release must
be reserved for safety functions. This type of tripping increases
wear on the opening mechanism. Repeated use reduces the
mechanical endurance of the circuit breaker by 50 %.
044313
MX or MN voltage release.
DB115605
0.
7
0.35
Un
0
Possible openin
g
F
a
ils
af
e openin
g
1.1
Opening conditions of the MN release.
DB115606
0.85
Un
0
F
a
ils
af
e closin
g
1.1
Closing conditions of the MN release.
PB103752-32
DB115607
Del
a
yed
trip order
Inst
a
nt
a
neous
trip order
Ti
m
e-del
a
y
unit
MN
D
2
D1
10 1
2
3
6
MN release with a time-delay
unit.
Wiring diagram for
emergency-off function with
MN + time-delay unit.
DB115608
0.
7
Un
0
Possible openin
g
F
a
ils
af
e openin
g
1.1
Opening conditions of the MX release.
559E1880.indd
version: 1.0