Issue:
What is the difference between SWD and HID ratings, and what do they mean?

Product Line:
Circuit Breakers

Environment:
QO

Resolution:
Circuit breakers used to switch 120V or 277V fluorescent lighting circuits must be listed and marked "SWD" or "HID"
Circuit breakers used to switch high-intensity discharge lighting circuits must be listed and marked "HID"
UL 489 (Standard on Molded Case Circuit Breakers) permits "HID" breakers to be rated up to 50A, whereas an "SWD" breaker is rated up to 20A.
The tests for "HID" breakers include an endurance test at 75 percent power factor, whereas "SWD" breakers are endurance-tested at 100 percent power factor.
The contacts and the spring of an "HID" breaker are heavier duty, to dissipate the increased heat from greater current flow during the HID ignition period. [Courtesy of Mike Holt newsletter 10/22/03]

Note:  
SWD marking indicates "Switch Duty" rated for fluorescent lighting.
HID marking indicates "High-Intensity-Discharge" duty rated for lighting applications High Intensity Discharge lighting.

Released for:Schneider Electric USA