Product Overview
Allen-Bradley N12 Type N Heater for Motor Overload Relays
Thermal overload heater elements are calibrated components used in Allen-Bradley overload relays and motor starters to protect electric motors from sustained overcurrent. The heater converts motor line current into heat, closely matching motor thermal behavior and providing inverse-time protection rather than instantaneous interruption. Proper selection is based on motor nameplate current and relay design, not horsepower alone, across single-phase / three-phase AC motor systems.
Product Condition
Unused, New Old Stock.
Product Overview
The Allen-Bradley N12 is a Type N thermal overload heater element from the legacy N-Series. It installs into compatible Allen-Bradley overload relays and magnetic motor starters that accept screw-in Type N heaters. Under sustained overload conditions, the heater warms the relay’s bimetal or eutectic mechanism until the calibrated trip point is reached.
Key Features
- Allen-Bradley Type N thermal overload heater element
- Designed for compatible Allen-Bradley overload relays and motor starters
- Provides inverse-time motor overload protection, typically Class 20
- Heater selection value corresponds to approximately 1.25 A motor full-load current
- Each N-number is electrically calibrated and not interchangeable
- Common physical form factor across Type N heaters with different trip behavior
- Part of the legacy N-Series used in NEMA motor control equipment
Applications
- Motor overload protection in magnetic motor starters
- General-purpose AC motor control circuits
- Small single-phase and three-phase induction motors
- Low-current motor applications near 1.25 A FLA
- Maintenance of legacy Allen-Bradley NEMA starters
- Industrial control panel repair and refurbishment
Frequently Asked Questions
What does the N12 heater number represent?
The N12 designation identifies a specific thermal calibration tied to a narrow motor full-load amp range. Heater size is selected using Rockwell Automation heater tables based on the motor nameplate FLA and application conditions.
Are Type N heaters interchangeable if they physically fit?
No. Although Type N heaters share a similar mounting style, each N-number has a different electrical calibration. Using an incorrect heater size can lead to nuisance tripping or inadequate motor protection.
How does the N12 compare to other N-Series heaters?
The N12 is intended for lower full-load current motors than an N14 or N15. In the same overload relay frame, an N12 will trip at a lower sustained current.
What equipment is this heater designed to work with?
The N12 is designed for Allen-Bradley overload relays and magnetic motor starters that accept Type N heater elements, commonly found in legacy NEMA motor control assemblies.
You can maintain proper inverse-time motor protection in a legacy magnetic starter by installing this N12 Type N heater element into the existing overload relay block matched to the motor’s nameplate full-load current.
