Altech Corp.: Miniature Circuit Breakers with Unique Features

The UL489 series, with its exceptional electrical ratings, is the ideal solution for branch circuit protection. These current limiting circuit breakers minimize the short circuit current to a relative small amount in an extremely short time. This limits the short circuit’s potential harmful energy. The current limiting attribute was recently confirmed by UL tests.

The UL508 manual motor controller/supplementary protector offers a unique way of protecting various loads including single phase motors and any components in the control circuit of a UL508A industrial control panel. The supplementary protectors tested according to UL1077 are suited for any control circuit and supplemental protection.

The UL489 miniature molded case circuit breakers come in AC and DC versions. The AC version is dual voltage rated from 0.3A to 63A at 240V AC and 0.3A to 32A at 480Y/277V AC. The DC version is rated from 0.3A to 63A at 125V DC (1 pole) and 250V DC (2 pole). Combining the AC voltages in one design along with the industry unique dual terminal design for accepting standard wire along with ring tongue terminal wire keeps the flexibility up and the stocking requirements down. The unique housing characteristics are featured in each of the UL489, UL508 and UL1077 versions and make the circuit protection side of a UL508A panel look uniform and clean. The offering is completed by the largest line up of IEC style busbars with UL approval. The busbars are rated in AC and DC to accommodate the respective voltages in the miniature circuit breaker series.

Current Limiting Confirmed by UL Tests
Industry ONLY dual wire terminal connection (cage clamp and ring tongue compatibility combined in one design); no need to special order ring tongue versions!

  • Terminal barriers are serviceable
  • Individual part numbers printed on each breaker
  • Clear protective marking area cover
  • Dual voltage (480Y/277V and 240V AC) design greatly reduces stocking requirements
  • DC version available up to 250V DC


  • Branch circuits
  • Motors
  • Transformers
  • Heaters
  • Control circuits
  • Outlets