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Thread: HACR type breakers
06-02-2007, 12:50 AM #1
10-31-2007, 08:24 PM #2
Re: HACR type breakers
43. HACR Type — A circuit breaker that has been found acceptable for use in heating, air-conditioning and refrigeration equipment comprising group motor installations is marked “HACR Type” in conjunction with the UL Mark. This marking alone, however, does not indicate the acceptability of the circuit breaker in these installations. For an acceptable installation, the end-use equipment must be marked to indicate that “HACR Type” circuit breakers may be used for branch circuit overcurrent protection. The 2005 NEC permits the use of any inverse-time type circuit breaker in heating, air-conditioning and refrigeration equipment comprising group motor installations.
Back in the mid 80's UL changed their testing procedure with the end result that today all "new" multi-pole breakers are automatically HACR rated.
10-31-2007, 08:57 PM #3
Re: HACR type breakers
I'm not sure.
HISTORY OF HACR RATINGS (underlining is mine)
For many years Underwriters Laboratories® (UL)® required special testing of circuit breakers used in group motor applications in air conditioning and refrigeration equipment. UL had Listed these circuit breakers as HACR Type and they were used to meet the requirements of Article 430-53(c)(3). At first, UL restricted the HACR listing to circuit breakers rated 240 Vac or less and 60 A maximum. In the early 1990s SQUARE D® Company and UL worked together to redefine the test parameters for UL Listed HACR Type circuit breakers. These test parameters resulted in HACR ratings for circuit breakers rated 600 Vac and less and 250 A maximum as a second step.
By these test parameters HACR Type circuit breakers were the same as other types of inverse-time circuit breakers except they were additionally investigated by UL and determined to be suitable for motor branch circuit protection on group installations. Initially, these circuit breakers were tested and Listed to UL 489, the standard for safety for molded-case circuit breakers. Then additional investigation was done including tests to determine that the circuit breaker provided appropriate protection for the circuit components of typical heating, air conditioning, and refrigeration equipment. These included compressor motors and fan motors connected in group motor applications.
HACR RATINGS TODAY
A great number of circuit breakers were investigated by UL using the special HACR testing. It was found that all circuit breakers that passed the normal UL 489 tests also passed the special HACR testing without a special design. As a result, UL 489 has been revised to recognize that all circuit breakers that satisfy the construction and test requirements for UL 489 Listing are also suitable for HACR applications.
Paragraph 7.7 of the 9th edition of UL 489 grants HACR listing to all UL 489 Listed circuit breakers. There is no longer a requirement for special testing. These circuit breakers are suitable for group motor applications requiring HACR designation.
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