Technical data

11/98

Appendix

Endurances

A–Endurance Without Maintenance

MASTERPACT 08 12 16 20 25 30 - 32 40 50 63

MP or MC

Mechanical 12,500 10,000 10,000 10,000 10,000 10,000 5,000 5,000 5,000

Electrical 480 Vac 10,000 10,000 10,000 9,000 8,000 4,000 3,000 3,000 2,000

600 Vac 10,000 10,000 10,000 7,000 6,000 2,600 2,500 2,500 1,500

B–Endurance With Service Maintenance

Electrical (480 Vac) or Mechanical

20,000 20,000 20,000 15,000 15,000 15,000 10,000 10,000 10,000

C–Endurance Required by Standards

Frame size 800 1200 1600 2000 2500 3000 4000 5000 6300

UL489 Mechanical 3,500 2,000 2,000 2,000 2,000 1,500 1,500 1,500 1,500

Electrical 500 500 500 500 500 400 400 400 400

ANSI Mechanical 12,500 NS 4,000 4,000 NS 1,500 1,500 NS NS

Electrical 2,800 NS 800 800 NS 400 400 NS NS

Important Notice:

All endurances given are based on normal operating conditions and conventional tests:

n Closing and opening operations at rated current

n Power factor: 0.75–0.80

As actual conditions differ, use these values only as inspection guidelines and periodically check

contact wear.

Under normal operating conditions of use, as determined by UL 489 or ANSI Standards (see table

C) and controlled by tests, MASTERPACT circuit breakers do not require maintenance. However,

these circuit breakers exceed, without maintenance and additional costs, the endurances required

by standards. See tables A and C. Service maintenance by a field service representative will extend

the endurance according to table B. This service can be performed on site and consists in changing

contacts, arc chutes and some other parts.

Example:

MP16 at 480 V requires no maintenance before 10,000 cycles (mechanical or electrical). Endurance

may be increased after servicing at 10,000 operations.