What does the endurance test consist of that a UL489 circuit breaker must pass?

Issue:
What is the endurance rating for the thermal magnetic breakers?

Product Line:
Circuit Breakers

Resolution:
Circuit breakers are tested to UL489 and CSA 22.2. For endurance, both thermal-magnetic and electronic circuit breakers must successfully complete the number of operations shown in the below table.

• Power factor shall be 0.75 to 0.80 lagging.
• Starting in the open position, the breaker is closed, then opened (this counts as one operation)
• The Full Load Operations Test is done at rated current and voltage
• The No Load Operations Test is done following the Full Load Test

Frame Size in Amperes	Full Load Operations	No Load Operations
0-100	6,000	4,000
101-225	4,000	4,000
226-600	1,000	5,000
601-800	500	3,000
801-2500	500	2,000
2501-4000	400	1,000

NOTES:
Circuit breakers are not tested until they fail, so the maximum number of operations is not known.
Environmental factors affect the life of a breaker, so the number of test operations in the table should not be interpreted as a guaranteed number in actual use.

Released for: Schneider Electric Canada