Question
Does UL certify combination AFCI circuit breakers that are intended for use in another manufacturer’s panelboard? If so, how can one identify these products and the panelboards in which they can be installed?
Answer
Yes, UL Classifies molded-case circuit breakers, including arc-fault circuit-interrupter combination type and branch-feeder-type circuit breakers for use in other manufacturers’ panelboards under the product category Circuit Breakers, Molded-Case, Classified for Use in Specified Equipment (DIXF), located on page 99 in the 2010 UL White Book. The Guide Information can also be found online at www.ul.com/database and entering DIXF in the category code search field.
This category covers molded-case circuit breakers rated 15 to 60 A, 120/240 V maximum that have been investigated and found suitable for use in place of other Listed circuit breakers in specific Listed panelboards, with ratings not exceeding 225 A, 120/240 V ac, to be connected to circuits having an available system short-circuit current of 10 kA maximum. The circuit breakers are Classified for use in specified panelboards in accordance with the details described on the circuit breaker or in the publication provided therewith.
In addition, Classified molded-case circuit breakers may also be Listed with additional features such as a ground-fault trip element, ground-fault circuit interrupter, arc-fault circuit interrupter, secondary surge arrester, transient-voltage surge suppressor, and the like.
A circuit breaker that is Classified only is marked on the side with the statement:
“Classified for use only in specified panelboards where the available short-circuit current is 10 kA, 120/240 volts ac or less. Do not use in equipment connected to circuits having an available system short-circuit current in excess of 10 kA, 120/240 volts ac. For catalog numbers (or equivalent) of specified panelboards, refer to Publication No.______ provided with this circuit breaker. If additional information is necessary, contact [Classified circuit breaker manufacturer’s name].”
A circuit breaker that is both Classified and Listed is marked on the side with the statement:
“This circuit breaker is Listed for use in circuit breaker enclosures and panelboards intended and marked for its use. This circuit breaker is Classified for use, where the available short-circuit current is 10 kA, 120/240 V ac or less, in the compatible panelboards shown in Publication No. ______ provided with this circuit breaker. When used as a Classified circuit breaker, do not use in equipment connected to circuits having an available system short-circuit current in excess of 10 kA, 120/240 V ac. If additional information is necessary, contact [Classified circuit breaker manufacturer’s name].”
The referenced publication is a compatibility list which tabulates the company name, catalog number, number of poles and electrical ratings of the Classified circuit breaker, in addition to the company name and catalog number of the applicable UL Listed panelboards, and corresponding UL Listed circuit breakers in place of which the Classified circuit breaker has been investigated. The compatibility list also details the maximum permissible voltage and maximum available short-circuit current of the supply system to the panelboard. The Classified circuit breaker is not suitable for the specified application if the system supply characteristics exceed the maximum values indicated in the compatibility list. One copy of the compatibility list is provided with each circuit breaker.
Circuit breakers which are both Classified and Listed have markings as above, with the addition of the Listing Mark, located on the side of the circuit breaker.
