NEMA Overload Relays

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NEMA overload relays are made to standards designated by the National Electric Manufacturers Association (NEMA). Also known as NEMA overloads, they are electromagnetic switches that send signals to contactors to de-energize circuits when excessive current or phase failure is detected, protecting motors, machinery, equipment, and high-voltage systems from overheating and being damaged.

NEMA magnetic overload relays combine with compatible contactors to create motor starter assemblies.

NEMA Thermal Overload Relays

NEMA Thermal Overload Relays

These NEMA thermal overload relays prompt contactors to break electrical connections with downstream equipment once a set temperature is reached to protect connected loads from overheating and causing damage. Thermal units, also known as heaters, contain either bimetallic strips or melting alloy solder materials. When the current exceeds a predetermined threshold and temperatures rise, the material bends or liquefies, causing the thermal unit to break the circuit and cause the contactor to break its power contacts. As the materials cool down, they will return to their normally closed position and the circuit can be reset automatically or manually.

Relay Mounting Style: Direct To Contactor

Direct To Contactor identifies that the overload relay mates directly to the bottom of contactors.

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Relay Mounting Style: Separately Mounted

Separately Mounted identifies that the overload relay can mount to surfaces with or without a carrier or terminal block support assembly.

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NEMA Electronic Overload Relays

NEMA Electronic Overload Relays
These NEMA electronic overload relays trigger contactors to break electrical connections with downstream equipment once the current reaches a pre-determined range of full-load amperage. They have adjustable current settings and use semiconductors to monitor for overload conditions and trip once the current exceeds that set point. Electronic overload relays turn circuits on and off faster, are more accurate, and have longer service lives than thermal overload relays.

Relay Mounting Style: Direct To Contactor

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Relay Mounting Style: Separately Mounted

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Note: Product availability is real-time basis and adjusted continuously. The product will be reserved for you when you complete your order.
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