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  1. #1
    Join Date
    Feb 2002
    Posts
    134
    Need to know proper technique for testing mill volt out put of thermopile.
    Any replys very helpful.
    Thanks,Catch_48

  2. #2
    Join Date
    Jun 2002
    Location
    Bemidji, Mn
    Posts
    3,573
    Hook your meter up to the leads, set to Millivolts, there ya go...
    You picked a fine time to leave me loose wheel...

    http://rapalaguy.spaces.live.com/

  3. #3
    Join Date
    Feb 2002
    Posts
    134

    Chad711

    Ok so you have generator dissconnected from fuel valve and test in the pilot mode what will be a avg. read.
    Next what set up to test main gas on read.

  4. #4
    Join Date
    Jun 2002
    Location
    Bemidji, Mn
    Posts
    3,573
    Depends on the type of gas valve. tcouples are usually around 30 mv and Generators can be up to 750 mv...

    Gas pressure depends on model too, ng or lp...
    You picked a fine time to leave me loose wheel...

    http://rapalaguy.spaces.live.com/

  5. #5
    Join Date
    Apr 2002
    Posts
    1,383
    The best way to test a pilot generator is under a realistic load. Robertshaw milivolt gas valves have a 12 ohm load on the magnet, so I have a twelve ohm resistor that I connect across the pilot generator leads, then connect my meter in parallell with the resistor.

    A minimum acceptable read is about 350 milivolts, while a new pilot generator and a good pilot flame generates about 500-550 milivolts.


    Occasionally, you find pilot generators that give high reads with no load, and zero reads when connected across a load. This testing procedure is more accurate and reliable than testing without a load in my experience.



    Seattle Pioneer

  6. #6
    Join Date
    Feb 2004
    Posts
    2,462
    What type of generator do you have ? (voltage 750 250 ie pg-1 pg-9 robertshaw honeywell) The way I have always taken reads is with a closed system (calling for heat pilot on)A- read take across generator terminals C- take across t'stat terminal B- this is what is left to operate valve take across operator terminals. When taking only an open read (not calling for heat) you will never see if the generator is breaking down under load. reads taken inder load also will show if there is excessive resistance in the system such as a poor splice,wrong t'stat loose wire etc. If we don't know what reads to expect it makes it difficult to troubleshoot.

  7. #7
    Join Date
    Apr 2004
    Location
    Ohio
    Posts
    5

    Thermocouple

    Procedure to test thermocouple 1) Use .1 D.C volt setting 2) Heat thermocouple 1/4" at end 3) Meter should read between 25 M.V.D.C 30 M.V.D.C

  8. #8
    Join Date
    Jul 2001
    Posts
    3,112
    James 2, those readings are way to low for a powerpile generator. Should read between 250 to 750 mv.

  9. #9
    Join Date
    Feb 2004
    Posts
    2,462
    When taking millivolt reads remember to take a closed read. I only take an open read to confirm an open in the system. (an open will show the same read as an open or closed read) I have seen many open reads say in the case of a thermocouple show 22 or so and a closed read of 0-1. Which of course is dead. Same thing with a P.G system. May show 500+ open and as low as 0 closed.

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