My T-8 heats up and shuts off

[larryMc2000]

I remember seeing a conversation about this before but after an hour or so of continuous my T-8 shuts off and won't re-start for 10-15 minutes.  I have contacted Tormek and they graciously replaced it with a new model assuming something was wrong with machine. Now to my dismay the replacement does the same thing. I'm wondering if this has anything to do with my power supply. I run with a solar setup charging four 130 ah batteries. Anyone else out there running off solar?

[Ken S]

Welcome to the active forum, Larry.

As a retired career troubleshooter for Ma Bell, I would want to know if the trouble follows if you use your Tormek with conventional electric power.

The other possibility, if you must use the solar power, would be to switch to a T4. The motor of the T8 draws 200 watts. The motor of the T4 only draws 120 watts. Don't pay any attention to the "30 minute" limit. That's an old leftover from the all plastic housing of the T3. Tormek corrected this with the redesigned zinc top of the T4.

Ken

[larryMc2000]

Ken,
Thanks for the question I appreciate your knowledge. I ran it for 2 hours on house power, it got real hot and smelled hot but never shut off.  It would usually shut off with shorter continuous use on the solar/battery power.  I measured the exact same voltage from the house and inverter. As far as switching to a T-4, maybe something I can do in the future but currently I have a handful of SG-250's I got a good price on.

Thanks

Larry

[Ken S]

Larry,

Part of my duties as a troubleshooter for Ma Bell involved "vendor meets". For chronic trouble, I would meet the equipment vendor at the job site. Working together, we would try to duplicate and isolate the trouble. I never cared whose trouble it was; we worked together and repaired it. With Tormek related trouble like yours, I am neutral and just looking to fix it, regardless of whether it is a Tormek problem or not.

While the trouble still might be Tormek related, the fact that you have the same trouble with two separate Tormeks makes me think that it is less likely Tormek caused.

Our member, Fernando, had trouble with his Tormek shutting off. I don't think it was ever finally resolved. He thought it was due to very high ambient temperature. Tormek suspected the motor switch. Unfortunately, Fernando lives in Columbia, and the nearest Tormek service area is in the US.

Must dash. I will return later.

Ken

[Jan]

Larry, thanks for sharing your issue with us.

When the problem continues also with the new Tormek machine than it is probably caused by the voltage generated by your inverter.

The inverter does not generate pure sine AC voltage but only quasi-sine AC voltage accompanied with spikes. This voltage unbalance can increase motor power consumption by 15 to 20%. This increase can lead to motor overheating. Common voltmeter is not able to detect the voltage unbalance.

My recommendations are:
1)   improve motor cooling by lowering the ambient temperature
2)   do not run the machine idle, because it generates more heat than under load.

Jan

[Ken S]

Jan,

Do the Uninterruptable Power Supplies with battery backups that many of us use to protect our computer equipment also smooth out voltage spikes?

Ken 

[Jan]

Ken, all UPS cause some harmonic distortion of the voltage/current. Inexpensive UPS units usually have significant departure from sinusoidal form. See the attached picture! The inverter "chops" the voltage in square waveform output which is rich in harmonics. Passive filters can reduce the harmonic distortion to some 10% at full load.

More sophisticated and more expensive UPS units can produce almost pure sine AC voltage.

Jan

[larryMc2000]

Thanks for all the good info. I will modify my operation and see how it goes.

[Ken S]

Larry, I hope you will persist in solving your overheating/stopping problem and will post your observations.

We have had several postings over the years with this problem. Unfortunately, many of us, like me, have never experienced this problem. If those of us, like you, who do experience it, will diligently try to isolate it and consult us, maybe we can solve the riddle.

Do keep us posted!

Ken