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B-2
Altitude derating
Altitude does not significantly affect circuit-breaker characteristics up to 2000 m.
Above this altitude, it is necessary to take into account the decrease in the dielectric
strength and cooling capacity of air.
The following table gives the corrections to be applied for altitudes above 2000
metres. The breaking capacities remain unchanged.
Compact NS630b to 3200
Altitude (m)
2000 3000 4000
5000
Impulse withstand voltage Uimp (kV)
8
7.1
6.4
5.6
Rated insulation voltage (Ui)
800
710
635
560
Maximum rated operationnal voltage 50/60 Hz Ue (V) 690
690
635
560
Rated current 40 °C
1 x In 0.99 x In 0.96 x In 0.94 x In
Intermediate values may be obtained by interpolation.
Vibrations
Compact NS devices resist electromagnetic or mechanical vibrations.
Tests are carried out in compliance with standard IEC 60068-2-6 for the levels
required by merchant-marine inspection organisations (Veritas, Lloyd’s, etc.):
2
b V
13.2 Hz: amplitude ±1 mm
13.2
b V
100 Hz: constant acceleration 0.7 g.
Excessive vibration may cause tripping, breaks in connections or damage to
mechanical parts.
Electromagnetic disturbances
Compact NS devices are protected against:
overvoltages caused by devices that generate electromagnetic disturbances
b
overvoltages caused by an atmospheric disturbances or by a distribution-system
b
outage (e.g. failure of a lighting system)
devices emitting radio waves (radios, walkie-talkies, radar, etc.)
b
electrostatic discharges produced by users.
b
Compact NS devices have successfully passed the electromagnetic-compatibility
tests (EMC) defined by the following international standards:
IEC 60947-2, appendix F
b
IEC 60947-2, appendix B (trip units with Vigi earth-leakage function).
b
The above tests guarantee that:
no nuisance tripping occurs
b
tripping times are respected.
b
Operating conditions
Installation
recommendations
DB128162
2000
(m)
DB128163
DB128164
Compact circuit breakers have been tested for
operation in industrial atmospheres.
It is recommended that the equipment be cooled or
heated to the proper operating temperature and kept
free of excessive vibration and dust.