Siemens / ITE K3B150 Molded Case Circuit Breaker

This bolt-on breaker is designed exclusively for legacy ITE and Siemens panelboards and switchboards configured for K-frame breakers. You must verify your panel interior labeling to confirm K-frame compatibility before installation.

Yes. Siemens acquired the ITE electrical line and continued producing these K-frame breakers under the Siemens name. A Siemens K3B150 is an exact, interchangeable replacement for an original ITE K3B150.

The LI designation means the trip unit provides Long-Time (L) and Instantaneous (I) protection. The Long-Time function handles sustained overloads using a fixed thermal element, while the Instantaneous function protects against short circuits using an adjustable magnetic element.

The breaker features a fixed thermal element for long-time overload protection and an adjustable magnetic element for instantaneous short-circuit protection. The magnetic pickup can be adjusted using the dials on the front face of the trip unit to coordinate with your system fault current requirements.

Yes. As a bolt-on molded case circuit breaker, it requires the appropriate strap kit or mounting hardware specific to your ITE or Siemens panelboard or switchboard chassis. The required hardware is dictated by the panel type rather than the breaker itself.

No. Circuit breakers must only be installed in panelboards and switchboards they are UL-listed for. Mixing brands without explicit cross-listing voids the UL certification and can lead to improper seating, overheating, and severe electrical hazards.