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nickel on relay/contactor

Has anyone seen this before? and why would someone do this?

thanks in advance


  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    Stupidity, laziness...I'm equally concerned about the exposed red conductor under the wire nut.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,597
    When I had a "No Heat Call" I think someone told me that there is not enough nickel plating on the contacts. This caused a poor electrical connection from time to time. So I added more nickel.

    Is there a problem?
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    JUGHNE Member Posts: 11,021
    IMO, it took some thought and effort to glue that nickel in place.
    I would guess it was to quiet the humming or chattering of the relay??
    Could have saved a component replacement.
  • mimodman
    mimodman Member Posts: 1
    we were called there for a tune up and my tech pointed it out. I just had never seen that before. I thought maybe as a heat sink. LOL the things you find out there.
  • HomerJSmith
    HomerJSmith Member Posts: 2,406
    edited April 2021
    The relay operates by magnetically drawing the plate to the coil core, closing the points. Nickel is non magnetic. I don't see how adding a nickel to the plate would stop chatter, of course loose wiring in a coil can vibrate, but the way to deal with that is to use a coil varnish on the coil . No need for a heat sink. It's a mystery wrapped in a riddle, wrapped in an conundrum, wrapped in an enigma, etc you get it.

    Take it off and see what transpires. You will be a nickel richer.
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,247
    I imagine that @Steamhead would have something to say about this. ;)

    Yours, Larry
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,597
    I have seen this before. Not a nickel but a penny. It is to reduce the 60 Hz vibration that sometimes gets acoustically amplified on some relays. It doesn't happen often but when it does it can be annoying to a customer. I believe this was a trade secret found in some classified documents on the dark web back in the early 1900s

    Every transformer, motor, and relay coil has the 60 cycle HUM. You may not hear it in every appliance but it is there. How the surrounding environment is affected will determine how loud it gets. Another trade secret trick used by oil-burner men was to put a loop of copper on the fuel line near the oil tank to prevent Tank Hum. A frequent phenomenon caused by fuel pumps operating 1725 RPM. Tank Hum was so prominent that Sunstrand (Now Suntec) started to place "anti-hum" wafers in their fuel pumps.

    But I always told the customer who complained about any HUM from ther heater... "It's because it forgot the words"

    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • HomerJSmith
    HomerJSmith Member Posts: 2,406
    edited April 2021
    Hum comes from 60 HZ vibration of the coil windings. You have to have vibration to have hum. Having dealt with electronics in my younger life, I have always used coil varnish to stem the vibrations. I use to build my own speaker systems and the cross overs coils would on rare occasions vibrate.