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Round-dial 10EE overload relay and field winding problem

perky2

Plastic
Joined
Jan 23, 2022
Ok, its been a few years since I restored this lathe and i forgot much of what i knew. Lathe started going wonky. Tripped breaker in dc panel. I reset it and it would run for about thirty seconds then kick out again. Started getting worse and would not reset. Would run if I manually press contact in. Then got really weird and when i tried to change speed would stop and go in reverse without touching anything else and forward contact stayed engaged. Turned on motor generator today and it smoked the breaker.Where can I get a new breaker? Any help would be much appreciated. Unfortunately I am not an electrical wizard. Thank you.


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Cal Haines

Diamond
Joined
Sep 19, 2002
Location
Tucson, AZ
That overload relay won't cause the symptoms that you're describing; it's the canary in the coal mine. You have some other problem that's overloading the DC panel. It might be a short in the field of either the spindle motor or the generator or perhaps a short in the generator rheostat. What do you mean by "the lathe started going wonky"? What exactly was going on when the problem first happened?

If someone doesn't have a spare overload relay, it can be replaced with a fuse. (The square-dial DC panel uses a 1A fuse instead of an overload device for the same circuit.) If you do find a spare, know that you have to move the heater from the old relay to the new one. The heater is the oddly shaped metal strip, located below the reset button and mounted with two screws. The heater is what controls the current level that trips the relay.

Cal
 

perky2

Plastic
Joined
Jan 23, 2022
It was running fine till it started tripping the breaker. I let it sit overnight and it would run for maybe 5 minutes then would trip the breaker. I checked all the brushes and they all seem to be making contact. Checked for loose connections and did not find any.The stopping and going in reverse is what I meant by going wonky.When the breaker tripped and would not reset I manually pushed the contact closed and the spindle motor would run. When I tried changing speeds it would change rpm if I turned the speed control slowly. If I tried changing speeds quicker it would stop and go in reverse just like you flipped the headstock lever to reverse without changing anything so I would quickly shut it down to prevent any damage. I actually have not run this much since I restored it but it always ran fine. The motor generator seems to run fine. Is there a way I could check the voltage coming into the breaker without killing myself or if you could walk me through some troubleshooting I would be grateful. If there is any information you need let me know and I will get it to you. Thank you
 

thermite

Diamond
Joined
Sep 21, 2011
Location
Sol, Terra
It was running fine till it started tripping the breaker. I let it sit overnight and it would run for maybe 5 minutes then would trip the breaker. I checked all the brushes and they all seem to be making contact. Checked for loose connections and did not find any.The stopping and going in reverse is what I meant by going wonky.When the breaker tripped and would not reset I manually pushed the contact closed and the spindle motor would run. When I tried changing speeds it would change rpm if I turned the speed control slowly. If I tried changing speeds quicker it would stop and go in reverse just like you flipped the headstock lever to reverse without changing anything so I would quickly shut it down to prevent any damage. I actually have not run this much since I restored it but it always ran fine. The motor generator seems to run fine. Is there a way I could check the voltage coming into the breaker without killing myself or if you could walk me through some troubleshooting I would be grateful. If there is any information you need let me know and I will get it to you. Thank you

"Reversing" when it should not?

Drawing higher current that it had been?

Running slower?

Read up on "brush timing" of the final-drive MOTOR then.

Sounds to me as if your brush mounting plate is loose and has rotated out of optimal position plus is STILL able to move a skosh.

DC Panel can't fix that.
Screwdriver can.

Unless it has cracked.
That, too can be fixed.
 

perky2

Plastic
Joined
Jan 23, 2022
Its not brush timing,I checked all the brushes and holders for problems. I know how to set timing with equal speed in forward and reverse. If I manually close the contactor it will run. When I change the speed is when things go haywire. I have only tried running it for a few seconds. I dont want to do anymore damage so I thought I would ask for help. I know you and Cal know these machines like the back of your hand. I dont have a schematic or the electrical knowledge to go poking around on my own so I thought I would ask for help. Thank you
 

thermite

Diamond
Joined
Sep 21, 2011
Location
Sol, Terra
Its not brush timing,I checked all the brushes and holders for problems. I know how to set timing with equal speed in forward and reverse. If I manually close the contactor it will run. When I change the speed is when things go haywire. I have only tried running it for a few seconds. I dont want to do anymore damage so I thought I would ask for help. I know you and Cal know these machines like the back of your hand. I dont have a schematic or the electrical knowledge to go poking around on my own so I thought I would ask for help. Thank you

CAL... knows the DC panel. And really, really well. not I.

I don't mind the design. I just don't like unobtanium components.

I would do it differently if I had to build one from scratch not because it is "wrong". But because I'd be using ONLY "present-day stocked" components.

4Q DC Drives don't use even one molecule of it, so I do not have the need.

Once I have finished making records of how my still factory standard MG does?

Annnnd I live long enough to "get a round tuit"...?? IF..

It will get a Solid-state DC Drive, same as the other one has.

But "3-Phase" not single-phase. There are SEVERAL of them already here to be tested

Also SEVERAL higher priorities.

Cal probably has far the better idea where to look next, but if brush timing is good, then I woold look for an intermittent in the control circuitry FOR the primary contactors.

Those will NOT arbitrarily flip between FWD and REV by themselves.
What is controlling them CAN do.

I had - some years ago, on a DC Panel I was donating to Jonathan Lewis, detected a wire broken right AT the solder pad. Stiffness of the varnished-stiff-(with-dirt-and-age) cambric sleeve and the (solid) wire kept it in contact with its proper pad... but only "mostly".

You may have just the same. THAT wire was UNDER the braking resistor pak, which I had removed for cleaning. I am not he who even bothered to sort out what did or did not happen when it made contact or did NOT as 100% of the orignal wire and conduit has already been removed from the machine. With a Milwaukee "Sawzall"!

I was also painting the Cambric sleeves with poor-lady store El Cheapo colored nail polish, and photographing that for Cal's "library".

The colours were intended to make it easier to trace the wires from a photo. "At the time.." I was not aware how many variations there ARE in the DC Panel world. Cal IS aware of most, if not all of those.

Jonathan may still have that panel. It was out of a 115 VDC piggyback exciter MG of 1942, His 10EE was an inline exciter of 1940 or '41 and already failed - as they do - in the Field generator section.

So he was using a transformer & rectifier for his field supply. Which loses the built-in feedback for load regulation. IF he used it at all, it would have been to pull parts. I think he has pulled but one. if ANY.

You could contact him. Shoot me an email if need be. We have stayed in contact.

Bill
 

perky2

Plastic
Joined
Jan 23, 2022
That may well be the case. The first time this breaker kicked out on me I started tugging on wires in the dc panel looking for loose connections or any bare spots. It ran ok for a while after that. I really would like to diagnose and fix this before I do anymore damage. This was a US navy machine with the original drivetrain all intact and funtioning. Thank you
 

Cal Haines

Diamond
Joined
Sep 19, 2002
Location
Tucson, AZ
First of all, this is not a circuit breaker, so let's stop calling it that. It's an overload relay. The typical AC circuit breaker is a two-terminal device that functions as a resettable fuse, both sensing and interrupting the current through the device. An overload relay is a four-terminal device: two terminals are used to sense the load current; two terminals are used to control something. If the two halves are wired in series, it can function like a circuit breaker, but that's not how they are typically used.

On this model DC control panel, one overload relay senses the current to the DC panel and everything that it feeds, including the fields of the generator and spindle motor, as well the big Ohmite rheostats. When that one operates, it kills power to the entire DC panel. The second overload relay senses the armature current and interrupts the forward/reverse relay control circuit, shutting down the spindle motor and generator.

The overload relay in question is probably the one that protects the DC panel. If that's the case, when you forced the main contactor closed, you forced the armature circuit to run, but without the spindle motor's field. When that is done, the spindle motor can rapidly run away and all sorts of strange/bad things can happen. In the future, never do that again; it's right up there with putting a penny in a fuse box. You probably have a short or perhaps a rheostat problem that's overloading the DC panel.

I'll have to do some digging to find the spindle motor and generator resistance tests; maybe I can do that this evening. In the meantime, I want you to do two quick tests to verify the identity of the overload relay:
  • Set your Ohmmeter on it's lowest range, usually 200 Ohms
  • Tests are done with the machine shut off.
  • Check for continuity between terminals E1 and E1-2 at the bottom of the DC panel. Use the metal tags on the wires to verify that you're on the correct terminals.
  • Check for continuity between terminals C3 and E2.

Cal
 

thermite

Diamond
Joined
Sep 21, 2011
Location
Sol, Terra
That may well be the case. The first time this breaker kicked out on me I started tugging on wires in the dc panel looking for loose connections or any bare spots. It ran ok for a while after that. I really would like to diagnose and fix this before I do anymore damage. This was a US navy machine with the original drivetrain all intact and funtioning. Thank you

The panels are ... a LONG way from the day they were new and pretty!

As was once sung about "the Bastard King of Eng-a-land":

"He waaaaaas... dirty and lousy and full of fleas, had his women by twos and threes"

But it is just TEDIOUS work to clean them up and trace ALL the wires, 'coz they are actually brute-simple at day's end and have no teeny-tiny parts like old computers had . before they had "Integrated Circuits".

Nowhere NEAR the challenge of the 17 tube 1938 Sparks-Withington nor 18-tube 1947 GE "Type 41" all-band console receivers I cut tooth on as a smart-alec kid!

You can do this.

Gather ye the schematics. Make a plan. Take LOTS of decent pictures. Make lots of notes. Ask for help when stuck. Revise the plan.

All PM community asks is that you pay attention and do your part, not ignore advice, argue with those who have DONE IT before, after sixth time asking the same question because you don't like the answers .."etc".

Then get all pig-headed and butt hurt over the noise about it.

We cannot reach the hardware across the wire even if we wanted to do.

You can reach it. Tedious, yes. Hard? Not really.
 

perky2

Plastic
Joined
Jan 23, 2022
Oh, believe me , I am old enough,64, to know I am way out of my element. I am very good at mechanical things when I can see how it is supposed to work.I have tried many times over the years to understand electricity and I just can not get a grasp on it. I can not see what it is doing so I can not diagnose what is wrong because I don't know what it is suppose to be doing. I don't know if that makes any sense to anybody but that's how I see it. I would be grateful for any tips on how and what to check.
 

thermite

Diamond
Joined
Sep 21, 2011
Location
Sol, Terra
I can not see what it is doing so I can not diagnose what is wrong because I don't know what it is suppose to be doing. I don't know if that makes any sense to anybody but that's how I see it. I would be grateful for any tips on how and what to check.

"Funny you should mention" "can't see it".

That was sooo freakin' FRUSTRATING . .having only a VOM, then VTVM, I had acquired my SECOND Oscilloscope by age nine and two more by age 13!
More since as I keep upgrading, but I only had to rebuild four of them from junk.

Back when I still had more brains than money.
(Funny how that reverses in later years, ain't it?)

But 'scopes are cheap as dirt nowadays!

Y'see.. nearly everything that happens in a 10EE falls within the "audio passband." So IF one had a probe that could SAFELY connect to an iPhone or laptop PC?

Most already have display software to analyse that "audio" spectrum.

There are in fact, such plug-in gadgets made. I'm no fan of their safety, however.

A 10EE with "Contactor Reversing" can draw a spike around five TIMES the service Voltage. 1500 Volts? And a bit.

Typical meters are also suspect. Check the ratings. And where made.

I prefer an inexpensive quad-trace Rigol 'scope, but the older one is a Fluke that cost the very EARTH when new, Had GREAT test leads.. so.. nothing for it but to buy a set of high-Voltage "multiplier" leads and no-gettee-fingers-here probes for the Rigol. Which cost MORE than the Rigol scope had cost. US-made leads. Vs Chinese made scope.

Meter, scope, or just "wet meat" (yerself!), HIGH VOLTAGE is the killer.
And that is NOT just a figure of speech!

A 10EE is chock full of "lethal" Voltages.

Rectified or rotating, Dee Cee is deadlier than AC. No reversal = no "OFF point that "might" THROW a body off. DC is called "stick and fry" or as our former moderator put it: being "rectumfried".

"Job One" is safe operating practices.

Habit of close-on 70 year for those among us as started with hollow-state and Tee Vee with high voltage Cathode Ray Tubes.

Potentially deadly-dangerous as to bad habits for those who came in with low shock hazard low Voltage transistor audio gear and silly-puters.

PM is not the only place to learn about such things. Nor the best. Internet is chock full of sources.

US Navy training courses and their publications are about as clear and well-written as anybody has ever published anywhere. Kinda inconvenient to call a tow-truck for a submarine 600 feet down? Every man has to know his speciality. And then some.

Those can be found cheap or even free without having to sign up and wear a uniform..

US taxpayer funds a thing? US public is entitled to the benefit of it.
So long as it is not classified for security reasons.

NASA publishes as well. And "not-only".

Never too old to learn new things. Maturity even makes it faster and less stressful than it might have been in impatient and less confident/relaxed youth.

Learning as a hobby in one's "golden years" even makes up for some of the "fun" things no longer as easy to do.

If-even a perpetually 23 year-old wife of 31 years would allow those!

:D
 

perky2

Plastic
Joined
Jan 23, 2022
Oveload relay it is. Continuity check on e-1 to e-1-2 has continuity,8.7 on meter. c-3 to e-2 has continuity, .3 on meter.
 

perky2

Plastic
Joined
Jan 23, 2022
Oveload relay it is. Continuity check on e-1 to e-1-2 has continuity,8.7 on meter. c-3 to e-2 has continuity, .3 on meter.

I found a schematic close to mine. I should not have gotten continuity on one of those with the overload relay removed should I?
 

Cal Haines

Diamond
Joined
Sep 19, 2002
Location
Tucson, AZ
What you're seeing is the resistance of the exciter's series field in combination with the spindle motor's field and some of the other stuff on the DC panel. But 9 Ohms is a lot lower than I would expect for that. Disconnect E1-2 at the bottom of the DC panel and it should read open.

Send me an e-mail and I send you my color coded version of the schematic for your machine.

Cal
 

Cal Haines

Diamond
Joined
Sep 19, 2002
Location
Tucson, AZ
It will be at least tomorrow before I can pull together the resistance tests for you. (I have about 300 pages of saved posts to search through.)

Cal
 

perky2

Plastic
Joined
Jan 23, 2022
It will be at least tomorrow before I can pull together the resistance tests for you. (I have about 300 pages of saved posts to search through.)

Cal

I really appreciate you taking time to help. If there is something I can do in return let me know. All my pictures and old posts from my restore must be gone, I can't find them.
 

perky2

Plastic
Joined
Jan 23, 2022
I found three of your previous threads, complete with photos, under the username perky:
In the last one, four years ago, you were reporting a problem with the DC panel overload relay and it doesn't look like it was resolved then.

Look in the first thread. I give directions for spindle motor resistance checks, start there.

Cal

Did the tests. a1 to a2 3.0. f1 to f2 5.5. The other ones where open. I put a 2 amp fuse where the relay was and it blows the fuse as soon as I start the motor generator. I must have lost my password at some point and reregistered. Thanks. Apparently after rereading my old posts I was having the same problem back then and never fixed it. I have not touched the lathe since then. I restored a couple cars and built a cnc plasma table since then and just never got back to it. Did you know your memory starts to fade as you get older?
 








 
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