Eaton Cutler-Hammer HMCP Series Thermal Magnetic Circuit Breakers

Eaton's Cutler-Hammer HMCP Series (Heat Magnetic Circuit Protector) is a circuit breaker designed specifically for motor and power distribution protection, providing dual overload (thermal protection) and short-circuit (magnetic protection). Suitable for industrial, commercial, and OEM equipment, this series offers a variety of specifications to meet diverse application needs.

1. HMCP Series Model Naming Convention

HMCP series model numbers generally follow the following format:

HMCP + frame current + breaking capacity + number of poles + tripping curve

Code Meaning Optional Values

HMCP Thermal-Magnetic Circuit Breaker -

Frame Current Maximum Carrying Current 30A / 60A / 100A / 200A

Breaking Capacity Short-Circuit Current Interrupting Class L (35kA), R (65kA), H (100kA)

Number of Poles Number of Circuit Breaker Poles 1P / 2P / 3P / 4P

Tripping Curve Protection Characteristics C (Standard), D (High Starting Current)

Example:

HMCP100R3C = 100A frame, 65kA breaking capacity, 3 poles, C-type tripping curve

HMCP60L2D = 60A frame, 35kA breaking capacity, 2 poles, D-type tripping curve

2. HMCP Series Common Models and Variants

(1) Different Breaking Capacities (L/R/H)

HMCP100L3C: 100A frame, 35kA breaking, 3 poles, C-curve (suitable for low short-circuit current systems)

HMCP100R3C: 100A frame, 65kA breaking, 3 poles, C-curve (standard industrial applications)

HMCP100H3C: 100A frame, 100kA breaking, 3 poles, C-curve (high short-circuit current applications)

(2) Different pole numbers (1P/2P/3P/4P)

HMCP100R1C: Single pole (1P), suitable for single-phase circuits

HMCP100R2C: Double pole (2P), suitable for single-phase or double-phase systems

HMCP100R3C: Three pole (3P), suitable for three-phase motor or distribution protection

HMCP100R4C: Four pole (4P), suitable for three-phase + neutral systems

(3) Different frame currents (30A/60A/100A/200A)

HMCP30R3C: 30A frame, 65kA interruption, 3 poles (small motor protection)

HMCP60R3C: 60A frame, 65kA interruption, 3 poles (medium load)

HMCP100R3C: 100A frame, 65kA Disconnection, 3 poles (standard industrial motors)

HMCP200R3C: 200A frame, 65kA disconnection, 3 poles (high current distribution)

(4) Different tripping curves (C/D)

HMCP100R3C: C-type curve (5-10 times rated current instantaneous tripping), suitable for general motors and transformers

HMCP100R3D: D-type curve (10-20 times rated current instantaneous tripping), suitable for high starting current equipment (such as compressors, crushers)

3. Other related circuit breaker series

If the HMCP series does not meet your needs, Eaton also provides the following similar products:

Series Features Typical applications

MCP (Motor Circuit Protector) Optimized for motor protection, no overload protection (needs to be used with thermal relay) Motor Control Center (MCC)

MCCB (Molded Case Circuit Breaker) Molded case circuit breaker, higher breaking capacity, adjustable tripping Main protection for distribution systems (such as the FAZ series)

MCB (Miniature Circuit Breaker) - Suitable for low-current protection in residential and commercial power distribution.

4. Selection Recommendations

Breaking Capacity (L/R/H)

L (35kA): Low short-circuit current systems

R (65kA): Standard industrial applications (recommended)

H (100kA): High short-circuit risk applications (such as large distribution cabinets)

Pole Selection

1P/2P: Single-phase or two-phase systems

3P: Three-phase motor or distribution protection

4P: Three-phase four-wire systems (with neutral protection)

Trip Curves (C/D)

C: Conventional loads (such as pumps and fans)

D: High starting current equipment (such as compressors and crushers)

Frame Current

Select based on the load's rated current. A 20% margin is recommended.