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How to Select a Ground Fault Relay – Commercial Kitchens

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Home » Engineering Resources » How to Select a Ground Fault Relay – Commercial Kitchens

Two base models are offered:

The correct AC ground fault relay series is based on whether all current carrying conductors fit through the aperture window. Included is a Ground Fault Relay Guide to ease selection of the the proper ground fault relay. To use the Ground Fault Relay Guide, the following details are needed:

  • 1)

    Branch circuit specifications: amperage capacity and load configuration example 50A, 208 VAC, 3 Phase, Delta (3+1)

  • 2)

    Circuit-Interrupter type: Shunt-trip breaker, contactor, or relay
    Note: Shunt-trip breaker is recommended

  • 3)

    Optional: appliance type

NK recommends either the AG or AGL series ground fault relay for commercial kitchens and other wet locations per 2020 Edition National Electric Code (NEC) 210.8 (B) through (F)), and 422.5 special appliances. Which relay is best for the branch circuit is dependent upon whether the wire bundle passes through aperture of the ground fault relay.

The Ground Fault Selection Guide is provided to ease the selection process and recommendations are based on using a shunt-trip breaker and THHN wire. Given numerous wire and local code variants the Ground Fault Selection Guide is for reference only.

Other than the THHN wire and/or non-NEC cable correction factors, use application note How to Calculate Bundle Diameter to confirm wire bundle will pass through the aperture of either the AG or AGL ground fault relay.

After verifying all current carrying conductors pass through the relay’s aperture, Click here to select the correct model for you application.

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Here is what Engineers have to say about our technical expertise...

“Changes to NEC 210.8 B-F have challenged all of us in the industry to find new GFCI solutions. When NK Technologies reached out to us recently, we decided to invest a few hours into meeting with their application experts. Five of our electrical engineering designers attended the session and considered it time well spent. NK Technologies has an in-depth understanding of the new NEC requirements and ground fault products designed to meet them. We are thankful for their time.”

PK Electrical
One of the top electrical and low voltage/communications design firms,
in both the private and public sectors, based in Reno, NV and Denver, CO.

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