Thermal Overload

[Grease_Monkey]

I have one lane that keeps tripping the thermal overload. (Jap Electrical 230-240V set up)
Here's what I have done/found so far...

Would originally trip the CB half way or thermal over load when ball hit pit cushion
could continuiously cycle it for hours with no TOL
Changed CB after it died on night - no more CB problems
Swapped motor with another lane
Swapped thermal O/L
All of a sudden every couple of frames...
Swapped TOL again

Had a feeling that it was related to triggering after watching the relay in the time delay module removed manual triggering link (Have ZOT) problem now back to about 3 per day and when it TOL's now the rake is usually between 180 and 270

I bet this problem is right under my nose Any help would be appreciated

[laze3]

Re: Thermal Overload

sounds like a bare wire somewhere to me !start looking. [img]/content/btubb/images/%%GRAEMLIN_URL%%/eek.gif[/img]

[masternut]

Re: Thermal Overload

Take a Clip on amp probe and place on one of the braker wires, and watch the meter as the pinsetter cycles.That will tell you at where the load rush is comming from.If it is pulling alot of amps as the rake is sweeping on first ball chech the oil in the gearbox,if oil is okay will can go from there.

Later
Peanut

[Beerman]

Re: Thermal Overload

I agree with masternut. Also, if you have a frozen bearing somewhere in the machine, such as a ball or pin wheel guide roller, the extra load on the motor while the deck is raising will kick the TOL.

[Grease_Monkey]

Re: Thermal Overload

Thanks for your help...
Anyhow heres what I found

Oil level OK
Jackshaft bearings righthand side questionable and a few others not so bad

Changes in current while rake is sweeping

Terminal U wire 72 Drawing 10.3A - 11.6A
Terminal U wire 58 Drawing 0.2A - 0.8A
Terminal U wire 112?? Drawing 0.2A - 0.8A
Terminal U wire 48 Drawing 0.3A (240 V pinsetter light)

Terminal W wire 23 Drawing 8.6A - 10.4A
Terminal W wire 113 Drawing 7.1A

Had a day off after coming back wire 23 connected to the W terminal was black, burnt and crisp (must have come loose when I tested it)

Also found the bolt that passes through the upper pin wheel guide rollers loose and of course the pin wheel rubbing on the rear frame

Ran with out a TOL all day YES!! Thought I had it

BUT...Walk in today and CB trips out first thing. My guess is that the TOL strips are fused together and that is why i didnt get any yesterday
will see tomorrow

Thanks again for your help so far

[ August 13, 2001: Message edited by: Grease_Monkey ]

[KL Kevin]

Re: Thermal Overload

Grease Monkey:

I could be all wet here, but:

The Thermal overload is wired in series with only one thing, the motor, right??

You've swapped all electrical components that could be responsible, by your first post.

My thought: A broken spring in the rake tube, with the pieces randomly binding up the coils, would put a tremendous load on the motor just before she got to 180, as the tube was getting fully compressed. If the thermal didn't pop, or was slow to, the breaker would. Is the deck on this machine jerky going up and down?? If so, this ~might~ be causing it.

If you have a spare tube, it might be worth the time to swap it out and see what happens. Just remember to use your threaded rod during removal, and properly de-compress the spring afterwards, lest you have the front of the tube shoot out of the masking unit and embed itself in the concourse wall [img]/content/btubb/images/%%GRAEMLIN_URL%%/eek.gif[/img] [img]/content/btubb/images/%%GRAEMLIN_URL%%/eek.gif[/img]

Kevin

[MNSCORER]

Re: Thermal Overload

Greasemonkey:
One often overlooked problem with thermals is a dry lowering hook eccentric, they should be lubed monthly with 90 weight gear lub.
They actually put the most strain on the motor, owing to the bearing surface they present, in relationship to the leverage they have, compared to the lowering hook.
Indeed, the hardest thing the motor has to do, is pick up the deck, with a full load of 70 pounds of pins, and bring the rake back at the same time.
One usually always finds a four to one failure in this scenerio.
Hope of some help.
Roscoe.

[Grease_Monkey]

Re: Thermal Overload

Seems like a long time since my first post on this topic. I dont get much time to go online lately...Replacement thermal blew up just after my last post maybe it was faulty Put the original back in and havent had any more problems

Thanks to all for your help