Suitability for Isolation (Positive Contact Indication)

Compact® NSF and NSJ 150 to 600 A Circuit Breakers

Section 2—General Characteristics

The limiting capacity of a circuit breaker is its ability to limit short-circuit currents.

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Isc

Prospective

 

Isc Peak

Prospective

Current

Prospective

Isc

Limited

Isc Peak

Actual

Current

Limited

Isc

tsc

t

 

The exceptional limiting capacity of the Compact® NS line is due to the double break technique (rapid

 

natural repulsion of contacts and the appearance of two arc voltages in series with a steep wavefront).

 

The limiting capacity of the Compact NS line greatly reduces the forces created by fault currents in

 

devices. The result is a major increase in breaking performance. In particular, the service breaking

 

capacity Ics is equal to 100% of Icu.

 

The Ics value, defined by IEC 947-2, is guaranteed by tests comprising the following operations:

 

Breaking a fault current equal to 100% of Icu three times consecutively

 

Checking that the device continues to function normally

 

Conduction of rated current without abnormal temperature rise

 

Protection functions perform within the limits specified by the standard

 

Suitability for isolation is not impaired

Longer Service

Current limiting circuit breakers greatly reduce the negative effects of short circuits on installations.

Life of Electrical

 

Installations

 

Thermal Effects

Less temperature rise in conductors, therefore longer service life for cables.

Mechanical Effects

Reduced electrodynamic forces, therefore less risk of electrical contacts or busbars being distorted or

 

broken.

Electromagnetic

Less disturbance for measuring devices located near electrical circuits.

Effects

 

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Schneider Electric Class 615 dimensions Longer Service, Life of Electrical Installations