Eaton HMCP100R4C Cutler-Hammer HMCP Series Thermal Magnetic Circuit Breakers

The Eaton HMCP100R4C (also sold under the Cutler-Hammer brand) is a 100A, 4-pole (3P + N) Molded Case Circuit Protector (MCCP) designed for motor circuit protection and short-circuit interruption in industrial and commercial applications.

Key Specifications:

Series: HMCP (Heavy Molded Case Protector)

Manufacturer: Eaton / Cutler-Hammer

Ampere Rating: 100A

Poles: 4 (3 phases + neutral)

Voltage Rating:

480V AC (common)

600V AC (verify datasheet)

Interrupting Capacity (AIC):

65kA @ 480V (high fault current withstand)

Trip Type: Magnetic-only (instantaneous short-circuit protection, no thermal overload protection)

Must be used with an overload relay (e.g., Eaton EOCR) for motor protection.

Mounting: Fixed or plug-in (varies by model)

Standards: UL 489, CSA, IEC

Typical Applications:

✔ Motor Protection Circuits (paired with an overload relay)

✔ Industrial Power Distribution (switchgear, panelboards)

✔ Short-Circuit Protection in 3-phase + neutral systems

Comparison with Other HMCP Breakers

Model Poles Current Rating Trip Type Common Use

HMCP100R4C 4P (3P+N) 100A Magnetic-only Motor circuits requiring neutral protection

HMCP100R3C 3P 100A Thermal-Magnetic General motor/power protection

HMCP30R4C 4P (3P+N) 30A Magnetic-only Small motor circuits

Replacement & Cross-Reference:

Direct Replacement: HMCP100R4C (same series)

Alternative Models:

Eaton FAZ-C100/4 (similar magnetic-only breaker)

Eaton GJL100 (thermal-magnetic alternative, but 3P only)

Compatibility: Check panel type (e.g., Eaton C-Series, Pow-R-Line).