Ul 489 Standard. Ul 1077 supplementary protectors used for overcurrent protection within appliances or electrical equipment where branch circuit protection is already provided or not required. The major physical difference between a ul 489 miniature circuit breaker and a ul 1077 supplementary protector is the required pole spacings.
Ul 489 1 inch through the air 2 inches over surface. Definitions from the standard ul 489 mccb on photo abb molded case circuit breakers tmax series by galco. These circuit breakers are specifically intended to provide service entrance feeder and branch circuit protection in accordance with the national installation codes in annex b ref.
The major physical difference between a ul 489 miniature circuit breaker and a ul 1077 supplementary protector is the required pole spacings.
A ul 489 device can be used as branch circuit protection and for supplementary protection. Ul 1077 3 8 inch through the air 1 2 inch over surface. Ul 489 january 15 2013. Under the standards of ul most circuit protection devices are investigated and covered by ul s recognition or listing services.
