Environmental Conditions

Ambient Temperature

The ambient temperature refers to the temperature of the air immediately surrounding the circuit breaker.

Operation temperature: -25 °C to +70 °C (-13 °F to +158 °F)

NOTE: Commissioning is possible at -35 °C (-31 °F)
Storage temperature: -50 °C to +85 °C (-58 °F to +185 °F)

Extreme Atmospheric Conditions

ComPacT NSX DC circuit breakers are designed to operate in industrial atmospheres as defined in standard IEC 60947-2 for the highest level of pollution (level 3).

They are tested for extreme storage conditions according to the following standards:

Standard	Title
IEC 60068-2-2	Dry heat, severity level +85 °C (+185 °F)
IEC 60068-2-1	Dry cold, severity level –55 °C (–67 °F)
IEC 60068-2-30	Damp heat, cyclic temperature +55 °C (+131 °F) relative humidity 95%
IEC 60068-2-52	Salt-mist test

To obtain the best use from the circuit breakers, install them in properly ventilated switchboards where excessive dust is not a problem.

Vibration

ComPacT NSX DC circuit breakers are tested against vibration.

Conformity tests are carried out in accordance with standard IEC 60068-2-6 at the levels of severity required by the merchant shipping regulatory bodies (IACS, Veritas, Lloyd namely):

2 Hz to 13.2 Hz with an amplitude of +/- 1 mm (+/- 0.04 in)
13.2 Hz to 100 Hz at a constant acceleration of 0.7 g

Electromagnetic Disturbances

ComPacT NSX DC circuit breakers are immune to electromagnetic disturbance.

They comply with the requirements of the electromagnetic compatibility (EMC) standard IEC 60947-2 Appendixes F and J - Overcurrent protection tests.

Check for compliance with EMC standards by testing for immunity to:

Overvoltages produced by the operation of electromagnetic circuit breaker
Overvoltages produced by atmospheric disturbance that pass through the electrical network (for example, lightning)
The use of apparatus emitting radio waves (such as radio transmitters, walkie-talkies, or radar)
Electrostatic discharges produced by the operators themselves

Conformity with EMC standards as described above helps to ensure that:

The circuit breaker operates correctly in a disturbed environment
- without nuisance tripping
- in accordance with the trip time.
There is no disturbance to any type of industrial or commercial environment.

Altitude

ComPacT NSX DC circuit breakers are designed to operate within specification at altitudes of up to 2,000 m (6,600 ft).

Operation above 2,000 m (6,600 ft) modifies the characteristics of the surrounding air (dielectric strength, cooling capacity) and requires derating.

Altitude derating table for ComPacT NSX DC circuit breakers:

Altitude (m/ft)		< 2,000 m (6,600 ft)	3,000 m (9,800 ft)	4,000 m (13,000 ft)	5,000 m (16,500 ft)
Impulse withstand voltage Uimp (kV)		8	7.1	6.4	5.6
Rated insulation voltage Ui (V)		750	710	635	560
Maximum rated operational DC voltage (V)	ComPacT NSX DC ≤ 250 V	250	220	200	175
	ComPacT NSX DC 250–500 V	500	440	400	350
	ComPacT NSX DC 500–750 V	750	660	600	525
Rated current (A)		In	0.96 x In	0.93 x In	0.90 x In

Altitude derating table for ComPacT NSX DC PV circuit breakers:

Altitude (m/ft)	< 2,000 m (6,600 ft)	3,000 m (9,800 ft)	4,000 m (13,000 ft)	5,000 m (16,500 ft)
Impulse withstand voltage Uimp (kV)	8	7.1	6.4	5.6
Rated insulation voltage Ui (V)	1,000	900	800	700
Maximum rated operational DC voltage (V)	1,000	900	800	700
Rated current (A)	In	0.96 x In	0.93 x In	0.90 x In

Altitude derating table for ComPacT NSX DC EP circuit breakers:

Altitude (m/ft)	< 2,000 m (6,600 ft)	3,000 m (9,800 ft)	4,000 m (13,000 ft)	5,000 m (16,500 ft)
Impulse withstand voltage Uimp (kV)	8	7.1	6.4	5.6
Rated insulation voltage Ui (V)	1,600	1,400	1,250	1,100
Maximum rated operational DC voltage (V)	1,500	1,300	1,150	1,000
Rated current (A)	In	0.96 x In	0.93 x In	0.90 x In