What are Circuit Breaker Conditions of Acceptability?

Issue:
Do Conditions of Acceptability apply to UL489 listed circuit breakers?

Product Line:
Circuit Breakers

Resolution:
No. Conditions of Acceptability apply to UL recognized components, but it does not apply to UL489 listed circuit breakers.  (See attached for a detailed article from UL on this topic)

UL Listed circuit breaker products have been investigated using applicable construction and performance requirements, and when installed in accordance with the manufacturer’s installation instructions, should provide a safe, code-compliant installation.

UL Recognized components will not be compatible with all end-product equipment applications. UL’s Listing evaluation of an end product includes an investigation of the construction and performance of all installed components.

Because recognized components are only intended for installation in end products whose safety is evaluated by UL separately, they may be incomplete in construction or restricted in performance capabilities. This factor precludes their safe installation by electricians or contractors in the field. UL Recognized Components have been evaluated by UL for factory installation within equipment where the component’s limitations of  use are known and investigated by UL. Finally, UL Recognized Components have conditions of acceptability that describe how components can be used within end products.

Examples of conditions of acceptability for a contactor may include:

• Component is not intended to be cycled by the operation of an automatic reset overload
• Terminals are to be factory wired only
• Suitability of the connections, including spacing between factory connectors, must be determined once installed within an end product
• Short circuit capability may need to be evaluated in the end-use application
• Spacing from exposed live metal parts to the enclosure must be evaluated in an end product

See attachment for full UL article on this topic.

Released for: Schneider Electric Canada