Square D B1.16 Contactor Thermal Unit B Series

Product Description

The SQUARE D B1.16 is a thermal unit designed as an overload relay element for use with B Series contactors and starters. Thermal units sense motor current through heat buildup and trigger the overload relay to disconnect the circuit when current exceeds the rated threshold, protecting motors from sustained overloads and phase-loss conditions. This small but critical component weighs 0.04 pounds and measures 2.4 inches in length, 1.2 inches in width, and 0.8 inches in height. Electricians and industrial controls technicians install these units as part of routine starter maintenance or when upgrading overload protection to match a new motor nameplate current rating.

The B1.16 thermal unit fits into B Series overload relay assemblies commonly found in commercial and industrial motor control applications. Typical installations include motor control centers, combination starters, and panel-mounted contactors controlling pumps, fans, compressors, and other three-phase or single-phase motor loads. It is selected based on the full-load amperage of the protected motor, so verifying the motor nameplate current before ordering is essential.

Key Features

• Thermal sensing element trips overload relay to protect motors from sustained overcurrent conditions
• Compact form factor: 2.4 inches long, 1.2 inches wide, 0.8 inches tall
• Lightweight at 0.04 pounds for easy handling and replacement
• Sold individually, allowing single-element replacement without purchasing a full set
• Direct accessory for B Series contactor and starter assemblies

Compatibility

Designed for use with SQUARE D B Series overload relay assemblies and compatible B Series contactors and starters, as stated by the manufacturer.

Installation Notes

Thermal unit replacement is typically performed by a licensed electrician. Always de-energize the starter or motor control center and verify absence of voltage with a calibrated meter before removing or installing overload relay elements. Select the correct thermal unit based on the motor full-load amperage per the motor nameplate and the manufacturer selection chart. Follow NEC requirements for motor overload protection when sizing and replacing thermal units.