Part of the legacy SF series, the Zinsco SF2C175 is a 175-amp, 2-pole molded case circuit breaker. It utilizes fixed thermal-magnetic technology for reliable commercial protection. Designed as an exact hardware match, this bolt-on breaker mounts into existing Challenger, Sylvania, and Zinsco panelboards. It eliminates complex adapters and crosses to the Eaton FD2175. With a 25kAIC rating at 480V, it handles demanding fault currents. The unit features standard lug terminals and is HACR rated.
Which panelboards are compatible with the SF2C175 circuit breaker?
This breaker is designed exclusively for legacy Challenger, Sylvania, and Zinsco panelboards that accept SF frame or F-frame molded case circuit breakers. Always verify your panelboard labeling to confirm frame compatibility before installation.
How is the SF2C175 secured to the panelboard bus?
It utilizes a bolt-on connection. The breaker bolts directly to the panelboard busbars, providing a highly secure mechanical and electrical connection that is typical for commercial and industrial applications.
Can the SF2C175 be installed in a 240V AC electrical system?
Yes. While it has a maximum voltage rating of 480V AC with a 25kA interrupting capacity, it is fully compatible with 240V AC systems. When applied at 240V AC, the breaker delivers a higher interrupting rating of 65kA.
What type of fault protection does the fixed thermal-magnetic trip unit provide?
The fixed thermal-magnetic trip unit delivers standard LI (Long-Time and Instantaneous) protection. The thermal component prevents overheating from sustained overloads, while the magnetic component trips immediately to clear severe short circuits.
Is this breaker a direct replacement for older Challenger SF frame breakers?
Yes, this unit serves as an exact replacement for original 175-amp, 2-pole Challenger, Sylvania, or Zinsco SF frame breakers. This allows you to maintain existing legacy panelboards without requiring a full system upgrade.
Why is Eaton or Cutler-Hammer listed as the parent brand for this Challenger breaker?
Eaton acquired the Challenger and Cutler-Hammer product lines. While this specific breaker retains the legacy Challenger, Sylvania, or Zinsco branding, Eaton now oversees the manufacturing and support for these legacy molded case circuit breakers.
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