Wiring repairs for 1941 Monarch 10EE

I purchased this motor-generator 10EE several months ago. Money was tight until recently. Now I have a 220 v 40A line feeding a 7.5 hp rotary phase converter in my shop.



The lathe came with this box in the back. I think it was a DC converter box for running the DC motor. I damaged it in moving the lathe into my house and have discarded it. Not sure it was functional before I mangled it.


My goal is to use the Monarch motor-generator unit. The original wiring has been altered to accept the after market DC converter, and I need to restore the wiring back to original.

Here's a picture of the motor starter. (Sorry for the odd angle, I had to dismount it to get a decent picture due to limited space at the back of the lathe.)


It looks similar, but not the same as the Allen-Bradly unit in this thread:
10EE starting circuit with Allen-Bradley contactor

I will be ordering the manuals from Monarch for my lathe. Hopefully there will be electrical diagrams included.

A question for the forum members, is this starter suitable for my lathe? If so, is it feasible to determine how it should be wired correctly?

Walt

Walt Dizzy said:

I will be ordering the manuals from Monarch for my lathe. Hopefully there will be electrical diagrams included.

Click to expand...

AFAIK it is a waste of time for a round dial as you will not a manual for your machine unlike the square dials.... Easier to just download the 1942 manual off the internet (which probably will not contain much electrical info for you) and search here for answers to your questions...

"Meanwhile, search within the Monarch forum for everything you have time to read where an 'MG' machine is involved."

Thanks, I am doing so. I may be able to sort out some of the wiring modifications with previously posted information.

Walt

I have been able to establish, for instance, that the coil on the motor starter is not 440 v, it reads 270 v instead and will probably run on 220v.

Walt Dizzy said:

I purchased this motor-generator 10EE several months ago. Money was tight until recently. Now I have a 220 v 40A line feeding a 7.5 hp rotary phase converter in my shop.
View attachment 89988
...

My goal is to use the Monarch motor-generator unit. The original wiring has been altered to accept the after market DC converter, and I need to restore the wiring back to original.

Here's a picture of the motor starter. (Sorry for the odd angle, I had to dismount it to get a decent picture due to limited space at the back of the lathe.)
View attachment 89996

It looks similar, but not the same as the Allen-Bradly unit in this thread:
10EE starting circuit with Allen-Bradley contactor

I will be ordering the manuals from Monarch for my lathe. Hopefully there will be electrical diagrams included.

A question for the forum members, is this starter suitable for my lathe? If so, is it feasible to determine how it should be wired correctly?

Walt

Click to expand...

Hi Walt,

Welcome to the club!

We've seen your machine here before. Here's a link to the thread: http://www.practicalmachinist.com/vb/monarch-lathes/i-have-aquired-10ee-265802/

The motor/generator (MG) was probably taken out of service for a reason. It could be as simple as a bad exciter shunt field resistor or a simple brush problem. It may also be that the MG is damaged beyond repair. It's going to take time, patience and willingness to work on things electrical in order to get it running again. Your machine has some pretty odd things going on with the wiring and it will take time to sort it out. What's your background in electrical stuff?

You can download a manual for you machine here: www.metalillness.com :: View topic - Monarch 10ee Manuals
Monarch does a nice job of putting together a custom documentation package for square-dial machines, but for round-dials like yours, not so good. For your money you will get a photocopy of the same manual in the link above, but the above manual is a high resolution scan of an original manual and much better quality. You will also get a "Handling and Installation" manual and a lubrication manual, both covering a number of Monarch lathes; they have about one page each that's specific to the 10EE. Monarch may be able to give you the correct electrical drawing for your machine.

Check the cover of the DC panel and the tag on the spindle motor and see if your machine has a 230 Volt excitation. If you order a manual, etc. from Monarch, make sure they give you the right electrical drawing for your exciter voltage. You do have a machine with an in-line exciter, so make sure they give you the drawing for an MG with an in-line exciter, probably drawing EE-2442 or EE-2452, depending on exciter voltage.

Your AC contactor appears to be an older Allen-Bradley contactor, similar to the one in my thread (which you linked to). It will probably work to run the MG, but it's not the original contactor. You may want to replace it, but we can deal with that later.

Cal

Fortunately the starter in question is a straightforward three phase one. Anything that can handle the current will work, even if he has to put it in a box on the wall. Also fortunate is that the relay box looks completely stock, including the braking resistors on the back. I can fix any of the relays or the braking resistors if required.

It sounds like the first order of business is to get the MG running. If it runs, then look for generator brushes hung or worn to the point they no longer make contact. If the commutators are in good shape and all the brushes are good, then the investigation begins.

Bill

Hi,

Cal, here is a picture of the tag on the spindle(DC?) motor:


Does the "Duty Volts 230" establish this lathe as having a 230 v exciter?

Thanks for the link to the thread started by the previous owner.

Thanks for your comments, all.

Walt

Edit/ "What's your background in electrical stuff?" I have a basic knowledge of electrical concepts such as E=IR, P=IE, series and parallel circuits. I can use a volt-ohmmeter. I can wire basic 110v AC supply circuit and keep the hot-neutral correct. The 220 v line I put in for the lathe is running a bench top milling machine without issues. I can (usually) get a solder connection to go together well. I'm pretty weak in reading circuit diagrams. Apparently I don't know much about electric motors judging by the discussions about the Monarch 10EE. /Edit

The nameplate reads as follows:

Line 1 - frame data

Lines 2 through 5 - Armature specifications

Lines 6 and 7 - Field specifications

The "duty" is stated to be intermittent, but we know from experience that these machines could operate 24/7/365 for the entire WW-II, and then some, and keep on ticking.

Armature is always 230 volts.

Field is usually 115 volts, except for a few, rare, 230 volt examples.

If the field is 230, then the exciter and the DC Panel would also be 230, not 115.

Walt Dizzy said:

... here is a picture of the tag on the spindle(DC?) motor:
View attachment 90240

Does the "Duty Volts 230" establish this lathe as having a 230 v exciter?
...

Click to expand...

Hi Walt,

That is the DC spindle motor. On that vintage motor they usually use line at the very bottom to list the motor voltages. Mine says "230 VOLTS ARMATURE - 115 VOLTS FIELD" and has the volts box empty, whereas yours says 230. I'm pretty sure that you have a 230 V exciter setup. For one thing, the field current and rheostat resistance for a motor 115 V field is 1.5A and 400 Ohms, respectively; yours are .75A and 1600 Ohms, which is what I would expect for a 230 V field. They probably don't list the field voltage on your machine separately because it's the same as the armature voltage.

OK. It sound's like you have a reasonable background in things electrical. Here's your homework assignment:

The first thing that we need to do is find out how the machine is currently wired. You need to trace out and sketch the wiring from the AC input to the machine through to the T1 to T3 terminals in the terminal box on the motor/generator (MG). (The MG terminal box is behind the cover at the operator's feet and under the chip pan.)

You need to trace out all of the wiring connected to the AC contactor's coil circuit. The explanation in this thread should help you understand how that works: Your contactor is a bit different from the Allen-Bradley (AB) contactor in the above thread. Yours only has two overload devices and does not have the "hold-in" switch (terminal numbers 2 and 3) above the coil; instead, it probably uses the forth pair of contacts at the top to serve that purpose. In that respect, it's more like the original Cutler-Hammer (CH) contactor than the above AB contactor. You might want to read the explanation of the CH starting circuit here: If you understand how the two circuits work (they are very similar) you will be in good shape. If not, sing out.

Note that there are two wires leaving the contactor compartment via the conduit at the top: those wires connect to the neutral switch in the drum switch, under the spindle nose. There are three wires that go out the bottom of the compartment to the start/stop station on the front of the machine. You need to trace all of those wires out and sketch how they are connected to the coil, the small contacts on the sides of the overload devices and to the terminals at the top.

Post a photo of the inside of the disconnect box on the back of the machine and note the size of the fuses. I expect to see fuses around 30A, if present.

Post a photo of the inside of the MG terminal box showing all of the terminals. Note what wires on the right side are connected to the T1 to T4 terminals. The AC motor wires should have metal tags on them with numbers from 1 to 9. If the AC motor is connected for 220/240 AC, you should find the wires connected as follows: T1: 1 & 7; T2: 2 & 8; T3: 3 & 9. Wires 4, 5 & 6 should be connected together, either as in independent bundle or using terminal T4.

Cal

All good points, Cal.

On my 5 HP General Electric spindle motor (for my square dial) the field has four wires in the connection box, and is wired in parallel for 115 volts. I presume that GE did this for its own convenience, so it could make a few 230 volt field motors, for those who were so inclined.

Only two wires are actually brought out to the DC Panel, of course.

This is a compound-wound motor, as it was designed for a WiaD or Modular drive.

Cal Haines said:

Hi Walt,

The first thing that we need to do is find out how the machine is currently wired. You need to trace out and sketch the wiring from the AC input to the machine through to the T1 to T3 terminals in the terminal box on the motor/generator (MG). (The MG terminal box is behind the cover at the operator's feet and under the chip pan.)

You need to trace out all of the wiring connected to the AC contactor's coil circuit. The explanation in this thread should help you understand how that works:

http://www.practicalmachinist.com/v...rting-circuit-allen-bradley-contactor-172647/
​

If you understand how the two circuits work (they are very similar) you will be in good shape. If not, sing out.

Note that there are two wires leaving the contactor compartment via the conduit at the top: those wires connect to the neutral switch in the drum switch, under the spindle nose. There are three wires that go out the bottom of the compartment to the start/stop station on the front of the machine. You need to trace all of those wires out and sketch how they are connected to the coil, the small contacts on the sides of the overload devices and to the terminals at the top.

Post a photo of the inside of the disconnect box on the back of the machine and note the size of the fuses. I expect to see fuses around 30A, if present.

Post a photo of the inside of the MG terminal box showing all of the terminals. Note what wires on the right side are connected to the T1 to T4 terminals. The AC motor wires should have metal tags on them with numbers from 1 to 9. If the AC motor is connected for 220/240 AC, you should find the wires connected as follows: T1: 1 & 7; T2: 2 & 8; T3: 3 & 9. Wires 4, 5 & 6 should be connected together, either as in independent bundle or using terminal T4.

Cal

Click to expand...

Hi Cal,

I think it might be useful for me to post some initial results: I'm working on everything you asked for, but it's taking time to put it all together.

For starters, the disconnect box doesn't have any fuses. I took it all apart, cleaned and painted it and put it back together though.


The motor contactor with the coil connects with the headstock drum switch and start/stop switch combo as your diagram indicates, at least through the starting circuit. I still need to confirm the run circuit is OK.

I found 2 defective components. The most serious appears to be the stop switch which has 1k-100k of resistance depending on how one of the rear terminals is flexed. The other is that the finger(?) contact on the drum switch for center position is burned off at the end. There is enough contact remaining to make an electrical connection though.



The terminal block mounted against the AC-DC generator (Motor-Generator?) has the end of main power cables from the contactor connected to cables running to the generator which are doubled up, with one exception. The metal tags are very difficult to read, but appear to be 3&9, 2&8, and another 2 by itself on the 3rd terminal. There is a loose/broken off wire with a 7 tag on it. (I doubt that there are actually 2 wires with tag 2 on them. It's very difficult to see the tags clearly. Probably the pairs are as you state 1&7, 2&8, 3&9))

There is a 4th terminal with no wires on either side of it. The 5th one has a wire with tag GF1, the 6th GS2, the 7th GS1, the 8th is GA2, the 9th is GA1. These are the motor-side tags, most of the wires on the other side of the terminal block are not tagged. The only ones that are agree with their motor-side counterparts.

The picture of the terminal block I supplied doesn't seem to convey much information, please guide me to post what you need.

There are 3 wires twisted together, I can read 4 and 6, the other tag is too far behind the main casting to read, probably safe to assume it's 5. At least until proven otherwise.

Back at the contactor. The 3rd and 4th contact set are jumpered together. Not sure what, if any difference that makes.

I think this is starting to make sense. At least the connection through to the AC motor leads 1&7, 2&8, 3&9. These are one or the other of the rotor/stator windings, are they not? Then the leads on the other terminals must be for the other windings? Or the generator side of the unit?

Walt

AFAIK all the wires are tagged both ends. With a meter you should be able to ID all of them and either make temp paper tags from masking tape or get one of those machines that print them on a plastic ring/tab. Some of mine were hard to read until I got cleaning and straightened them out somewhat.

Oh and I don't know if anyone has ever tested their switch box for asbestos but mine sure looked like some of the internal parts were cast from it

Walt Dizzy said:

...
For starters, the disconnect box doesn't have any fuses. I took it all apart, cleaned and painted it and put it back together though.
View attachment 90647

Click to expand...

Whoever wired this up apparently didn't know that you are not allowed by code to use a white wire as a "hot" wire. It's a safety thing, so that you can see at a glance what wires are hot; white, bare and green wires are reserved for wiring that is at ground potential). You can tape the ends of the white wires black or blue and you're good. The ground wire also needs to be connected.

Walt Dizzy said:

The motor contactor with the coil connects with the headstock drum switch and start/stop switch combo as your diagram indicates, at least through the starting circuit. I still need to confirm the run circuit is OK.

I found 2 defective components. The most serious appears to be the stop switch which has 1k-100k of resistance depending on how one of the rear terminals is flexed. The other is that the finger(?) contact on the drum switch for center position is burned off at the end. There is enough contact remaining to make an electrical connection though.

Click to expand...

I don't know who made the drum switches. A quick peek at eBay didn't reveal any similar switches. Someone here may have a switch that they can sell you. Monarch may also have switches that they've pulled out of machines that they are reconditioning.

The contacts on the typical 10EE start and stop switches are pretty primitive. Can you post a photo of yours?

Walt Dizzy said:

View attachment 90648

The terminal block mounted against the AC-DC generator (Motor-Generator?) has the end of main power cables from the contactor connected to cables running to the generator which are doubled up, with one exception. The metal tags are very difficult to read, but appear to be 3&9, 2&8, and another 2 by itself on the 3rd terminal. There is a loose/broken off wire with a 7 tag on it. (I doubt that there are actually 2 wires with tag 2 on them. It's very difficult to see the tags clearly. Probably the pairs are as you state 1&7, 2&8, 3&9))

There is a 4th terminal with no wires on either side of it. The 5th one has a wire with tag GF1, the 6th GS2, the 7th GS1, the 8th is GA2, the 9th is GA1. These are the motor-side tags, most of the wires on the other side of the terminal block are not tagged. The only ones that are agree with their motor-side counterparts.

The picture of the terminal block I supplied doesn't seem to convey much information, please guide me to post what you need.

There are 3 wires twisted together, I can read 4 and 6, the other tag is too far behind the main casting to read, probably safe to assume it's 5. At least until proven otherwise.

Click to expand...

The good news here is that the AC section of the motor/generator (MG) is connected to the AC contactor. So the MG was probably in service when the machine last ran. Now, it may have failed, leading to the machine getting sold. Based on the DC box in the coolant compartment, the exciter may have failed--we'll worry about that later.

The bottom 4 terminals in the MG panel are used for the AC section of the MG. The terminals above are used for the generator section, including the exciter. You should find wires on the left heading off through the conduit to the DC control panel, near the spindle motor, and wires on the right going through the back of the panel to the generator and exciter. (On later model MG machines with a belt-driven exciter, the exciter wires go out the flexible conduit on the right of the terminal box.) The wires for the AC motor and DC generator typically look slightly different, but go through the same hole. All of the generator and exciter wires should have tags the start with G or E.

You only list 9 terminals; round-dials typically have 12 terminals. The top two terminals should be E1 and E2; that's where I would expect to find wires leading to the add-on box that was in the coolant pump compartment on the back of the lathe (if, in fact, it was a replacement for a failed exciter). What connects to the GF1 wire? Can you find GF2? (GF1 and GF2 are the generator's shunt field and should connect to the exciter and the generator potentiometer in the motor compartment).

Can you post a photo of the entire MG terminal panel? (I know that with an inline-exciter MG, part of the terminal box is hidden.)

We'll want to do a resistance check on all AC motor leads before we try to power it up. That's for later.

Walt Dizzy said:

Back at the contactor. The 3rd and 4th contact set are jumpered together. Not sure what, if any difference that makes.

Click to expand...

There's probably a jumper on the line side, which is used to power the coil when the contactor closes. I would not expect to see a jumper on the load side of the contacts. This contactor has four sets of contacts, like the original Cutler-Hammer contactor. The terminal in the back is the line (hot) side and the one in front is the load side of each contact. If it's like my Allen-Bradley contactor, you can push up on the bottom of the armature and close the contacts. You should read 0 resistance between the line and load sides of each contact when the armature is pushed up. Obviously, don't fiddle with any of this stuff when the machine is connected to power.

Walt Dizzy said:

I think this is starting to make sense. At least the connection through to the AC motor leads 1&7, 2&8, 3&9. These are one or the other of the rotor/stator windings, are they not? Then the leads on the other terminals must be for the other windings? Or the generator side of the unit?

Walt

Click to expand...

The 9 numbered wires go to the six windings (3 pairs) in the AC motor's stator. Each winding pair can be connected in series for high voltage (440 VAC) or in parallel for low voltage (220 VAC). The rotor windings are not brought out; they are powered by induction. The four terminals on the bottom are AC, for the AC motor section; the terminals above are DC and connect the generator and exciter together and to the DC control panel, next to the spindle motor.

What we need to do now is: 1) sort out the coil circuit of the AC contactor and get it working with the motor disconnected at the MG terminal box; 2) repair the broken #7 wire and verify that the extra #2 is actually #1; 3) verify the AC winding resistances and check for shorts to the case; 4) test the AC section by running the MG.

Cal

"Whoever wired this up apparently didn't know that you are not allowed by code to use a white wire as a "hot" wire. It's a safety thing, so that you can see at a glance what wires are hot; white, bare and green wires are reserved for wiring that is at ground potential). You can tape the ends of the white wires black or blue and you're good. The ground wire also needs to be connected."

Thanks, will do.

"The contacts on the typical 10EE start and stop switches are pretty primitive. Can you post a photo of yours?"



"The bottom 4 terminals in the MG panel are used for the AC section of the MG. The terminals above are used for the generator section, including the exciter. You should find wires on the left heading off through the conduit to the DC control panel, near the spindle motor, and wires on the right going through the back of the panel to the generator and exciter. (On later model MG machines with a belt-driven exciter, the exciter wires go out the flexible conduit on the right of the terminal box.) The wires for the AC motor and DC generator typically look slightly different, but go through the same hole. All of the generator and exciter wires should have tags the start with G or E.

You only list 9 terminals; round-dials typically have 12 terminals. The top two terminals should be E1 and E2; that's where I would expect to find wires leading to the add-on box that was in the coolant pump compartment on the back of the lathe (if, in fact, it was a replacement for a failed exciter). What connects to the GF1 wire? Can you find GF2? (GF1 and GF2 are the generator's shunt field and should connect to the exciter and the generator potentiometer in the motor compartment).

Can you post a photo of the entire MG terminal panel? (I know that with an inline-exciter MG, part of the terminal box is hidden.)"



First, I made a mistake in listing the wires coming off the right side of the MG terminals. Apologies for adding to the confusion. However, there are 11 terminals. The corrected list from top to bottom is:

(Empty terminal. Seen at top of terminal box apart from the rest of the terminal block.)
GA1
GA2
GS1
GS2
GF1 (red wire)
GF2 (red wire)
(Empty terminal)
1
2&8
3&9

The terminal numbers refer to the metal tags on the wires on the right side of the terminals. All these wires go into the MG. The empty terminals have no wires connected on either side.

I found the wires which were connected to the add-on box.
One connects to the left side of the terminal which has GF1 on the right side. (The left side has a second wire which goes into the lower of two conduits which appears to go to the DC control panel.)
The other wire is spliced to the end of a wire coming out of the same conduit . At a guess, that wire was originally connected to one of the MG terminals.

There are no wires with E1 or E2 metal tags on the right side of the terminals. There is wire on the left side with a plastic tag E2. It's connected across from the GF1 wire (and shares the terminal with the wire from the add-on box). However, it goes into one of the conduits to the DC control panel and does not go to the MG.

Walt

Is it possible the in-line exciter is simply gone from my lathe? Here's a picture of the left end of my motor-generator. Is that where the exciter should be?


(I searched for a couple of hours on the PM site and have not been able to come up with a picture of a MG with in-line exciter.)

Walt

thermite said:

There's one - rather poor graphic - in a parts-manual online somewhere. I'll have a recce if someone doesn't post something better first.

Update ..

An outside-the-site Google search turned up a photo a PM member posted:

Inline Exciter, 1941 10ee Photo by bosleyjr | Photobucket

So yes, that part seems missing outright.

Adding; And that is not a show-stopper, even if you cannot find an original to complete yours. Several MG's - inline especially - have had the functionality replaced by a transformer and simple bridge rectifier. Dunno if it is 'as good', but it does work.

Bill

Click to expand...

Thanks much Bill. This explains a lot.

I'll start researching the replacement options. A quick search on eBay last night didn't turn up anything useful.

Walt

thermite said:

...So yes, that part seems missing outright.
...

Click to expand...

No. He has an early model motor/generator (MG) with an in-line exciter. The AC motor, exciter and generator are all built on a common shaft.

Walt,

Please stand by. The problem that led to your exciter being decommissioned may be a minor one.

I'll have a reply to your earlier post in a while.

Cal

thermite said:

...
DC from an unfiltered rectifier output is 'rougher' (120 Hz ripple..) than that from the Reliance rotating generator, which impairs stable speed regulation and makes life tougher for at least one of the relays. Hence the 'new' panel.

Click to expand...

I'm not aware of any problems of a simple rectifier causing problems with any relays in the DC control panel. Please post a link to your source.

Also, if you're suggesting that Walt could replace his MG with a piggyback exciter MG, you're wrong. Monarch had to modify the base to accommodate the piggyback units and he has the old style base, as does Bosleyjr.

Cal

Walt Dizzy said:

...
"The contacts on the typical 10EE start and stop switches are pretty primitive. Can you post a photo of yours?"

View attachment 90812View attachment 90813

Click to expand...

Hi Walt,

The stop button has been replaced at some point. You'll want to find another suitable button on eBay. The switch you have is an Allen-Bradley 800T-XA. There are lots of them on eBay. Be aware that the contact block and the button are separate parts and can be mixed and matched. Another 800T-XA contact block should work with your button, but I’m not really sure. There were lots of options within the series.

The original button was a normally closed (NC), momentary action switch. When you pressed the stop button it broke the contactor's coil circuit, causing the contactor to open and shutting off power to the MG. I prefer the type of switch with the large mushroom head that stays in the open position once pushed, so that you have to deliberately pull it back out before you can restart the machine. The large head is nice because you could hit it with your knee in an emergency.

For purposes of testing the coil circuit only, you can replace the stop switch with any NC switch; a household light switch will work.

Let's proceed with the steps that I outlined earlier:

1. sort out the coil circuit of the AC contactor and get it working with the motor disconnected at the MG terminal box;
2. repair the broken #7 wire and verify that the extra #2 is actually #1;
3. verify the AC winding resistances and check for shorts to the case;
4. test the AC section by running the MG.

We're still at step #1. If the AC section of the MG is dead, the MG may be beyond economical repair, so let's get that far before we worry about everything else. Note that step #1 likely involves changing which of the contactor's terminals power the coil circuit in order to get it to work reliably with your rotary phase converter.

Cal

Walt, your exciter is missing altogether. I can see the stub shaft sticking out the end of the generator where the exciter mounts. I have mine off right now because I subbed a transformer/rectifier supply for it. My exciter is 230 and yours is likely also 230. Later ones are 115. If you don't have the exciter, you can build a supply to replace it and if all else is ok, it will work. There's a very slight drop in RPM's under load, then it stablizes and pulls like a train, EE style. My EE is #9960, built a couple of months after yours. I can take a pic of my start contactor if you need it. JinNJ

Walt, one other thing, while I remember[don't know when I'll be back online]. Your MG will rotate in the opposite direction from the piggy back type, naturally, since it's in backwards[?] compared to those later MG's. CCW when facing the fan at the TS end cover, or CW facing the generator behind the panel. Did someone already substitute a supply for the exciter in that machine? Is there a 230vdc with it?
Cal's right, get the AC working and then proceed from there...carefully. BolsleyJr posted the mostly correct schematic for the '41 with 230 exciter, should match yours closely.