ITE Siemens HM3F800 Circuit Breaker

This HM series breaker is designed for use in compatible legacy ITE and Siemens panelboards and switchgear that accept bolt-on molded case circuit breakers.

It features Long-Time and Instantaneous (LI) trip functions. The thermal element provides delayed tripping for sustained overloads, while the magnetic element trips instantaneously during short-circuit faults.

The HM series was originally manufactured by ITE. Following the acquisition of ITE by Siemens, these breakers are often branded as ITE-Siemens or Siemens. They are functionally identical regardless of which brand name is printed on the label.

It utilizes a bolt-on connection to attach directly to the panel busbars. This provides a highly secure mechanical and electrical connection suitable for industrial applications.

No, it uses a thermal-magnetic trip unit which operates mechanically based on the heat and magnetic fields generated by the current passing through it. It does not require an external power source to trip.

Lug configurations can vary based on the specific installation requirements. You will need to verify that you have the correct mechanical or compression lugs sized for your conductor material and wire gauge.

Installation should only be performed by a licensed electrician. Always ensure the panelboard is completely de-energized and follow proper lockout and tagout procedures before attempting to bolt the breaker to the busbars.

Yes, because Siemens acquired ITE, a Siemens branded HM3F800 is a direct drop-in replacement for an older ITE breaker with the exact same catalog number.

Molded case circuit breakers like the HM3F800 can typically be mounted vertically or horizontally without affecting their tripping characteristics, but you must follow the specific panelboard manufacturer guidelines for proper orientation and clearance.

Standard thermal-magnetic molded case circuit breakers without line and load markings are generally suitable for reverse feeding, but you must verify the specific labeling on your breaker and adhere to local electrical codes before reverse wiring.