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Introduction

Troubleshooting and repairing a "Stuck Relay" error.

This repair procedure applies to any OpenEVSE with an open-air relay (contactor) such as the 50A - Struthers - Dunn.

If your relay is a sealed unit, replace the entire relay.

  1. EV standards (IEC and SAE) require charging stations to provide soft start and soft stop of each charging session.
    • EV standards (IEC and SAE) require charging stations to provide soft start and soft stop of each charging session.

    • A properly functioning station should never require relay maintenance.

    • Ensure that the button on SAE J1772 plugs and lock/unlock are functioning properly to automatically remove all load before disconnecting vehicle.

    • The plug should never be disconnected under load if the button/unlock are working correctly.

  2. Turn power off to your OpenEVSE unit at the breaker
    • Turn power off to your OpenEVSE unit at the breaker

    • Validate that your OpenEVSE unit is off

  3. Open your OpenEVSE unit
    • Open your OpenEVSE unit

    • Validate that voltage is not present with your multimeter to ensure electricity is off

  4. Inspect the relay, ensure the contacts open and close as expected.
    • Inspect the relay, ensure the contacts open and close as expected.

    • Gently tug any stuck contacts to free them.

    • If the relay is seriously damaged, melted, bent, broken, or the contacts cannot be separated, replace it.

    • If relay is lightly pitted, or has other debris or build-up as shown in picture, continue guide to clean.

  5. 'Ensure any sharp metal burrs are removed from the edges of contacts. A metal file might be required. Cut a piece of coarse emery cloth roughly 3x the width of the contact (normal sandpaper is not recommended as it can leave deposits of other metal types on the contact surface) Fold the piece of coarse emery cloth, and place it between one set of contacts at a time. Apply gentle pressure to the contacts and sand evenly between the two surfaces.
    • 'Ensure any sharp metal burrs are removed from the edges of contacts. A metal file might be required.

    • Cut a piece of coarse emery cloth roughly 3x the width of the contact (normal sandpaper is not recommended as it can leave deposits of other metal types on the contact surface)

    • Fold the piece of coarse emery cloth, and place it between one set of contacts at a time. Apply gentle pressure to the contacts and sand evenly between the two surfaces.

    • Repeat process above using coarse, medium, and fine emery cloth to ensure a good connection.

    • Close the relay by gently pressing the plastic top bracket. Ensure an even and flat connection between the contacts.

  6. Once your contacts are evenly sanded, use contact cleaner and a q-tip to scrub each contact surface removing any build-up, metal, or grease
    • Once your contacts are evenly sanded, use contact cleaner and a q-tip to scrub each contact surface removing any build-up, metal, or grease

  7. Reassemble your OpenEVSE and power it on.
    • Reassemble your OpenEVSE and power it on.

    • Monitor the self-test to ensure errors have cleared

    • Attach a vehicle and charge at the full rate, monitor the OpenEVSE unit for any excessive heat build-up.

    • If any excessive heat is detected on the OpenEVSE unit, replace the relay.

    • Slowly plug and unplug the vehicle a few times ensuring the relay opens and closes as expected each time.

Finish Line

Alex von Gluck

Member since: 12/08/2021

1 Reputation

1 Guide authored

3 Comments

@dahan55 what vehicle are you primarily charging on the OpenEVSE?

I've been told this maintenance should not be needed by the OpenEVSE team, however after charging my Bolt EV for two years I've already needed to clean and replace the relay once due to wear. (This procedure got me an additional year from the relay before it started sticking again)

Alex von Gluck - Reply

I have a Mustang Mach-E Extended Range AWD. The OpenEVSE worked flawlessly for a little more than a year and a half. Then the relay got stuck and wouldn't open properly. I still don't know why it did that. I called the company and they explained what the error message meant and told me to follow these instructions above. If it gets stuck again, I am to call them back to do some brainstorming. The support guy answered immediately, was very helpful and courteous, and clearly seemed to know the device. I hope I won't have to call them back, but if I do, I would imagine the same level of competence and expertise.

David Dahan -

This worked. Very easy. Thanks.

David Dahan - Reply

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