Exploding Telechron!

Discussion in 'Electric Horology' started by moon_man157, Feb 5, 2017.

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  1. moon_man157

    moon_man157 New Member

    Feb 5, 2017
    Country Flag:
    Region Flag:
    Okay so hasn’t blown up recently, it’s probably been out of order for decades. I recently purchased a Telechron 1H1412 but unfortunately, it's not working. When I opened it to see what might be the problem I noticed a lot of soot. Many people talk about replacing the motor in these clocks but it looks to me like the coil might be the problem since that is where the soot appears to have come from. I found what appears to be a reputable supplier for the motor (H-3) but where should I get a coil from? And then there's the question of, is it the coil, the motor, or both? I would hate to buy a new motor only to find a need a coil. I would really appreciate any suggestions you could offer.

    20170205_113857.jpg 20170205_113926.jpg 20170205_114734.jpg 20170205_114744.jpg 20170205_114820.jpg
  2. Tinker Dwight

    Tinker Dwight Registered User

    Oct 11, 2010
    Calif. USA
    First question is, is it really soot or discoloration and dust that is
    sticking there from the heat of the motor.
    If the clock has been in an environment where there is a smoker,
    there will be a build up of tobacco tars from the smoke near the motor.
    This is caused by the thermal convection of the hot motor coil.
    It constantly pulls in outside air and it squeezes by the coil, depositing
    the gunk on the colder metal plate.
    If in the kitchen, frying can have similar effects. ( Ever clean an
    exhaust fan? )
    As for the coil working or not, plug it in for about 15-20 minutes.
    Unplug it first and then put your hand on it.
    It should be about 35C. Hot but not so hot you think it is going to
    burn your hand.
    If it is cold or too hot, it should be replaces.
    The motor part itself does not get noticeably hotter than the
    feild core metal.
    Tinker Dwight
  3. David S

    David S Registered User
    Donor NAWCC Member

    Dec 18, 2011
    Professional Engineer - Retired
    Brockville, On Canada
    Country Flag:
    Region Flag:
    #3 David S, Feb 5, 2017
    Last edited: Feb 5, 2017
    With the unit plugged in you can hold a steel screw driver blade near the pole pieces around the rotor and see if the screwdriver buzzes / rattles as you approach the pole pieces. If it does then the coil is good.

    I have seen those "sooty" marks on electrical equipment before and agree with Tinker's opinion.

  4. davefr

    davefr Registered User
    NAWCC Member

    Nov 29, 2008
    Semi Retired Engr. Mgr - Currently Rebuilding Tele
    Country Flag:
    Region Flag:
    That black soot is perfectly normal. It's probably a result of decades of outgassing of lubricant combined with heat and oxidation. Test the coil with an ohmeter. If it reads around 600 ohms it's electrically OK. However be extremely careful with the terminal strip. It's held onto the body of the coil with only a paper wrapping. That paper get's brittle and the least amount of flexing/movement of the wiring will break it loose. That will also likely break the tiny coil wires. They're about the thickness of a human hair.

    I'd suggest reinforcing the coil with a few wraps of 3M #27 glass cloth tape and then anchor the wiring to the frame of the movement with a knot or tie wraps. (like shown in your images)

    I can supply used/tested coils but I doubt you need one. They're incredibly reliable and almost never burn out.

    More troubleshooting info is here:
  5. moon_man157

    moon_man157 New Member

    Feb 5, 2017
    Country Flag:
    Region Flag:
    Thank you all but especially davefr, your website is a great resource. It's also the "reputable supplier" mentioned in my first post.
  6. Larry48075

    Larry48075 Registered User

    Mar 23, 2009
    Michigan, USA
    Country Flag:
    Region Flag:
    I have restored more than 100 Telechron clocks, and nearly all have had that sooty coating on the insides. It is normal. When it coats the dial, it is a problem to remove.

Similar Threads - Exploding Telechron Forum Date
Pappy's Telechron Forum - What Happened? Electric Horology Oct 6, 2017
Telechron restored, Electric Horology Feb 27, 2017
Telechron questions Electric Horology Jan 7, 2017
Telechron H3 Motor. Electric Horology Dec 12, 2016

Share This Page