Hello

I recently moved my workshop 2 months ago and have had problems with getting my 10EE started again after wiring it up in the new shop.

Im running the machine off of an American Rotary phase converter and the machine is getting it required 240 volts phase to phase and its 120 volts line to ground.

The main start up switch down below on the front of the machine will not start the machine any longer as it should when everything is working properly.

The motor starter electrical box which is located on the backside of the headstock is not fuctioning properly. It contains a master contact switch.

The main contact switch should be pulled closed and be held closed when the machine power is turned on and is working properly.....Now it has to be manually held closed (with the housing removed so I could get at it ) for it to remain in contact and to have the smaller piggyback motor start up and keep running.

Once the piggyback motor is running , the main spindle switch will not turn the main motor on. With some fiddling and poking around my electrician was able to get the spindle running. But it wont stay on.

There is a electrical box located directly under the variable resistor that controls the main spindle speed. When that box was opened up and the contacts were manually pressed together, then the main spindle finally started.

Im stumped and my electrician doesnt deal with this type of equipment very often so he's a little stumped aswell.

I should also state that the machine worked fine in my old shop. I simply unwired, moved it across town to the new shop and re-wired it.

Thanks
Dennis

Sometimes, the "off button" contacts get oil and dirt on them. Remove the four screws on the switch plate, pull it out a little, and spray contact cleaner on the contacts and rotate the round copper washer.
Clean the on button contacts also.
That is for the main contact to start the generator.
If the forward and reverse DC contacts "spindle switch" is not holding, in my experience indicates low exciter voltage. It should be around 120volts DC off terminals E1 and E2 " I think", I usually test the exciter off its brush holders.
Also you have to make sure, the wild leg off your cornverter is not on the switch leg. And the generater is rotating in the proper direction.

Dennis,

Was the machine running from the same rotary phase converter at the previous location?

Cal

Alas, 10EEs are designed to operate from utility three-phase. Phase Perfect three-phase also works well.

There are problems when a single-phase-capable 10EE (WiaD and Modular) is indeed operated from single-phase, or an RPC-capable-10EE (Sundstrand and M-G and others) is operated from an RPC.

Occasionally, the Cutler-Hammer main contactor (this could be substituted by an Allen-Bradley, or similar, on a few examples) is miswired at the factory so that the "three-wire control station" is returned to the B phase, not to the C phase.

Changing the one wire which returns the control loop to the C phase cures this problem.

By convention, in most utility three-phase installations, the B phase is the "wild leg". Also, the B phase could be powered by an "open ∆" transformer called a "kicker". The A and C phases are usually supplied by the large distribution transformer, and this transformer is the source of 120/240 for the premises.

By code, the phases within the premises panelboard are labeled left-to-right or top-to-bottom as A, B and C, so it is not too difficult to trace back and find which feeder conductors are A and C.

Cal

No...the machine was running on a homebrew style phase converter that came with the machine when I bought it approx 18 months ago from a gentleman in Montreal.

I purchased a new American Rotary 15Hp phase converter when I moved into my new shop. It was purchased to allow me to run 2 additional cnc machines aswell as the 10EE.

Im currently waiting for my buddy ( electrician with 4 years exp) to come by shop with an older more experienced guy that works with him to take a look.
The older guy has specific experience with industrial machinery.

Im going to get him to read through the responses to this thread so far and hopefully with your shared knowledge and his experience I'll get this machine running again this evening.

Thanks again for all your help so far.
Dennis

I just had an industrial electrician come by and poke around for a few hours.
Ive had both of my electricians read your responses to this thread so far, and they have checked all the issues which you guys have recommended.

The machine is still not running, and this is where we're at as of now:

The machine is getting its required voltage, which is from the phase converter of 240 Volts 3 phase...thats not an issue.

As I stated in a previous post, whats happening here, or what is not happening, is the contactor coils are not closing properly on there own. If we manually close the contactor for the Exciter motor, it runs properly... but, the main spindle motor will not run via the spindle control. The main spindle motor WILL run if we manually close those contacts. So something tells me that the coils are not getting the required voltage.

What my electrician is now asking for is a Schematic of the wiring and required Voltage, whether AC or DC at all the contacts, as well as the coils for the contactors and the terminal strip voltages.

Were still stumped a little here but Im confident that we'll get to the source of this problem in the next few days.

Thanks again
Dennis

Pull the leads, and rotate 'em by one terminal... swap 'em all... if it's a 'wild leg' problem, you'll eventually get it right.

Like they say- EE's are picky about that. Also watch motor rotation- they (the generators) don't like to spin backwards.

"What my electrician is now asking for is a Schematic of the wiring and required Voltage"

That can be best had by contacting Monarch. From what I can gather, you have a Motor Generator powered machine, year unknown as yet, there are at least 3 different versions of the type, with possible many small changes through the years by Monarch, and maybe other changes made by owners.
One of the little things I get a chuckle out of, is showing electricians the drive systems in my EEs!

The easiest way to determine what voltage the machine wants is to look at the main contactor coils. The main contactor is in the box mounted on the back of the headstock - it's held in place by a couple of SHCS screwed through into the bed right at the bottom of the headstock, there should also be a big reset button in the middle of the cover. Pull that and look at the coil pulling the contactor down, there should be a voltage on the coil. Check the voltage supplied at the coil contacts.

When you press the "start" button, do you get a light?

Dennis,

We need to know if you have a round or square dial machine and if you have electric leadscrew reverse (ELSR). If you post a photo of the machine we can tell from the photo. We also need to know if you have the original Cutler-Hammer (CH) main contactor. The CH contactor looks like this:



Here's a thread that shows the starting circuit for a non-ELSR machine equipped with an Allen-Bradley main contactor (the circuit for a CH contactor is similar):
http://www.practicalmachinist.com/vb/showthread.php?t=172647&highlight=circuit

Others have already said this, but it is absolutely critical that you make sure the motor-generator (MG) is turning the right direction. Have you done that? You should find direction arrow on the plate attached to the MG, to the left of the terminal box. Remove the large cover on the front of the machine, under the chip pan, to get to the left end of the MG.

Once you have verified that the exciter is turning the right way, check its output voltage. You can check it across the E1 and E2 terminals at the top of the terminal box on the MG. You should read 115 VDC. If the machine has not been run for some time the exciter may have lost its magnetism, which would explain why the spindle direction switch is not working. (The starting problem is another matter, could be related to the RPC's wild leg, as already covered by others.)

Most of the relays in the DC control panel, next to the spindle motor are 115 VDC. The starting circuit for the main contactor is AC and the voltage should be either 220 or 440 VAC.

Cal

Hi guys

Sorry for not mentioning earlier that my 10EE is a 1943 round dial.
I recieved a wiring schematic today from monarch.

Im going to make sure that Ive checked and tried all that you guys have suggested so far....so heres the breakdown:

Donie: I checked the contacts on the main switch and everthing is fine.
In regards to checking the exciter voltage, my guys checked it and
Im pretty sure they were getting 120 volts. I had both my
electricians read through your post and they said that everything was
as it should be.

Cal: In regards to your first post.
As I mentioned yesterday, the machine was running on a different phase
converter in my old shop, but my electrician tells me that this cannot be
the source of the problem because the machine is getting the exact
same power supplied to it, just from a newer converter now.

Dave: Im just about to try switching the leads here in a few minutes.
My guys also checked and made sure that the exciter motor was
turning in the proper direction when they were here last night.

rke[pler: Please excuse my personal lack of technical knowledge in regards to
electrical components.
My electrician said that even though some of the components have
a stated maximum capacity stamped onto the outside, it doesnt tell
him what the component should be getting. This is why he
requested that I get a schematic for him. Thankfully Monarch
supplied me with one today.

Cal: 1943 Round dial
No ELSR on my machine
My contactor appears to be the same as the one in the picture that
you posted. It is a CH model. Im not sure if it is the OG stock unit
but it certainly looks like it is.

I did check the direction indication panel thats riveted to the left
side of the MG for conformation. Its turning the proper direction.
Im not sure if we checked the E1 and E2 terminals for the 115 VDC
last night. I can check that in a minute.

Im curious about the exciter losing its magnetism.
The machine has been sitting for approx 8 weeks now. If this is the
case, should I simply manually close the exciter switch and hold it in
place with a block of wood to allow it to run for awhile? Will this help
build up the magnetism again? Is there any risk of damaging any
other electrical components on the machine if I run the exciter like
that?

Thats it for now.
Thanks again for all your help so far.
Dennis

If I am reading the photo of the Cutler-Hammer main contactor correctly, it is setup for 220 volts, but certainly 240 would be fine.

When that machine was made, the standard North American voltage was indeed 220.

Immediately after the conclusion of the World War, it was 117/234 volts. Essentially 230 volts.

Several years later, it had crept up to 240 volts.

Just another tidbit of info here.

Last night to get the CH contactor to stay shut it had to be manually held closed. I did this by placing a wooden block in front of it to keep it closed.

I just fired up the machine again, and although the contactor wont close on its own still, it now stays closed on its own once it has been manually closed.
To turn it off I simply pressed the red reset button.

Whats your thoughts on this change? Do you think that the contactor magnet is becoming charged up again now that I've let it run a little bit.

Thanks
Dennis

Keep in mind, the spindle forward/reverse lever must be in neutral for the generator to start, there for when in neutral, it completes the start circut.
Your problems may be there.
peterh has posted about problems and fixes for the spindle switch.

Dennis, the contactor magnet isn't becoming charged up.

The CH contactor coil is only energized momentarily by pressing the start switch. By design, to hold it closed a set of contacts in the contactor then provide continuous power to the contactor coil after the start button is released. The start button is a momentary contact normally open switch. Pressing it closes it and provides power to the contactor coil, the now closed set of contacts in the contactor then power its coil.

Manually operating the contactor by pushing its armature to the closed position also closes the contacts which provide power to the contactor coil. It should stay in if the fwd/rev lever is in the stop position. As a safety measure the circuit to the coil that can be closed by the start button also has another switch which must be closed in the circuit. It's only closed with the fwd/rev lever in the stop position.

There are four switches in the circuit that operate the contactor coil. To provide momentary power to close the contactor both the start button switch and the fwd/rev safety switch must be closed. They only need an instant to pull in the contactor, it then latches closed by the circuit now powering the coil through its own contacts, the third switch.

The fourth switch is the stop switch. It's normally closed and in the latch circuit which powers the contactor coil through the contacts closed when the contacter is activated. It's job is to interrupt the circuit supplying the coil through the contactor contacts. Press it, the circuit to the coil opens and the contactor opens.

Check all of their operation.

The coils on a contactor act as an electromagnet, pulling on a steel bar in the contact plate. If it doesn't have enough power it can't pull the contacts closed. It sounds like yours is either not getting enough power to pull closed or that it's not able to generate enough field to pull the contact plate closed. You can check this by measuring the coil voltage and comparing it to the spec on the coil - a 440V coil will not pull in if you give it 220V. Similarly, a coil given a line and the wild leg from a rotary convertor might not get enough voltage to operate, it should be getting the line voltage.

If it's not the voltage or convertor it might be that the laminated core of the contactor isn't able to make enough field to pull in the contact plate. This message shows the disassembly and cleaning of an AB contactor:

http://www.practicalmachinist.com/vb...3&postcount=12

(On edit: all of the above is assuming that the contactor simply is not pulling in when you're pressing the 'start' button, and is maybe humming or clicking a bit. You can check that by hanging a voltmeter on the coil and pressing the start button and making sure that you're seeing the right voltage across the coils.)

"The CH contactor coil is only energized momentarily by pressing the start switch."

The main contactor's coil is continually energized, whenever the machine is operational.

It is initially caused to be brought in by pressing the (normally open) START switch.

It is maintained continually thereafter by the action of the contactor's own "hold" contact set.

It is caused to be dropped out by pressing the (normally closed) STOP switch.

It is also caused to be dropped out by the overload block, which (normally closed) functional contacts are in series with the (normally closed) STOP switch.

This is a very simple application of the classic line voltage control "three-wire control station".

Larger Monarchs use 115 volts for their control stations, but 10EE Monarchs use line voltage control, usually 230 or 460 volts.

OK, that means that the run part of the starter circuit is working and your coil is not open. That leaves these possibilities:

1. Wrong coil
2. Mechanical problem with the main, 4-pole relay (the one you have been pushing in to start the MG).
3. Problem with the center contacts on the headstock switch
4. Problem with the start button
5. Broken wire in start leg
6. RPC wild leg connection

What does the tag on the coil read? You can see the coil and it's tag, top-center, in this photo:



Check the voltage across the coil, as Russ suggested. Take an AC reading across the two terminals on the coil when the start button is pressed, you should see 240 volts. If you see 240 volts when the start button is pushed then you can probably rule out problems 3, 4 and 5, above.

You can bypass the starting circuit to verify that the coil is working by connecting the right terminal of the coil to the L2 terminal, immediately to its right. (The 4 terminals are, left to right, L3, L1, L2 and 3.) Make sure you know what you are doing here. Make sure the other terminal connects to either L3 (typical) or L1. You should install the jumper when the power is disconnected. When power is applied the contactor should close and remain closed until power is removed. If it doesn't, you have either a bad/incorrect coil, a mechanical problem or the issue is with the RPC wild leg.

Did you try rotating in the 3 incoming phases, as suggested?

What does the left-hand terminal of the coil connect to?

What does the exciter voltage read?

Cal

I had a similar problem, but mine is a WIAD, and this advice may not help you. The contactor wouldn't latch or would drop out. I rewired the incoming main(breaker to machine) line to a much larger wire gauge, and the problem was solved. Since this problem has shown itself in your new location, something to look at.

Dennis,

I just finished a post with a detailed explanation of how the starting circuit works and some information on reading the Monarch wiring diagram:

http://www.practicalmachinist.com/vb...it-191465.html

Hopefully it will be of help to you and others.

Cal