Need help on my lathe electrical

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spro
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Joined: Mon Feb 20, 2006 11:04 pm
Location: mid atlantic

Re: Need help on my lathe electrical

Post by spro »

Well maybe but that switch between the traverse rod and the contactor...is the likely suspect. I culled out some old pics of my lathe and you can see hot chips sitting on that little case. Now I remember either making a new gasket or sealing it better.
choprboy
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Joined: Sat Oct 29, 2011 11:23 pm

Re: Need help on my lathe electrical

Post by choprboy »

I think you need to to post a bit more information... Which Enco model? What is your power supply situation? Is your voltage drooping when under load? Motor load when it happens?

From your previous description, it sounds like it is a control issue, not a motor issue, as it ran when you manually pushed in the motor relays. In addition to the safety cutout others mentioned, I see both a thermal cutout and a transformer (probably for relay coil control voltage) in the electrical box. Defective thermal trip or running too hot under high-speed load? Power drooping under load/low voltage out of the transformer causing the relays to chatter? The Enco manuals usually include a wiring diagram that would help track it down.
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whisperfan
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Location: Virginia, USA

Re: Need help on my lathe electrical

Post by whisperfan »

I believe I found it.
This item in the control box has a little black 'bar' sticking out above that 'dial' looking thing. When I pushed on it, it went in and clicked. I was looking for a fuse or a circuit breaker of some type, but I didn't expect the breaker to be black-on-black with no red or other color.

live and learn

Here's a photo of it.

Where do I find the model number of the lathe? I'd love to track down a manual
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Lathe019.jpg
spro
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Joined: Mon Feb 20, 2006 11:04 pm
Location: mid atlantic

Re: Need help on my lathe electrical

Post by spro »

Well, choprboy spotted that and it appears to be adjustable time delay/heat delay. Very cool. My older Enco doesn't have as sophisticated electrics. That isn't surprising because it is probably 25+years older. The castings are different, control locations are different but similarities remain.
Hopefuldave
Posts: 148
Joined: Wed Jun 01, 2011 8:17 pm

Re: Need help on my lathe electrical

Post by Hopefuldave »

That uses the transformer to supply 24v ac for the contactor coils (via switches etc.). the transformer has a small white rectangular block attached that looks like a fuse holder, might be worth checking the fuse hasn't popped (disconnect supply first, the fuse is at 220!) - without the 24v control voltage, the motor will run when you press the contactors' physical buttons but won't stay running...

The "safety" switches on covers and the E-stop should show closed (short-circuit) when in correct running positions, and they work by opening and preventing the 24v control current flowing (so there will be 24v ac across 'em when open), if you don't have an ac voltmeter / multimeter a 24v bulb with a couple of soldered-on wires with alligator clips can be helpful, if the switch is open (i.e. "safe" and disabling the motor) the bulb will light when clipped to the switch terminals, closing the switch will extinguish the light when it's in running (closed) condition.

Dave H. (the other one)
Rules are for the obedience of fools, and the guidance of Wise Men - Douglas Bader
Hopefuldave
Posts: 148
Joined: Wed Jun 01, 2011 8:17 pm

Re: Need help on my lathe electrical

Post by Hopefuldave »

Your post came while I was typing! That's the motor overload, the dial sets the motor's rated full-load current, yes there's a thermal element in it plus (usually) a magnetic element, the thermal averages out the running current and the magnetic measures the instantaneous current, if either goes above the setting on the dial it disconnects the motor to protect it - good thing to have!

When it tripped, if you weren't doing something heavy, it might suggest there's something somewhere binding somewhere that put too high a load on the motor - or, of course, the overload might be a bit temperamental!

Dave H. (the other one)
Rules are for the obedience of fools, and the guidance of Wise Men - Douglas Bader
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