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Monarch 10EE-phase converter

kader

Plastic
Joined
Jun 11, 2002
I am purchasing a monarch 10EE of 1943 vintage. It has the original
motor generator setup. 3 phase 220 I assume, can this be ran off of a
static phase converter or how would you recommend setting it up?
THanks
p.s. If you could give me a reason why a static converter won't work but a rotary will I would appreciate it, I am an electrical idiot. Thanks again
 
I don't know for sure but I wouldn't bet on it. I'd use the rotary phase convertor.

If you have the circuit diagrams for your model I could look them over and see, I've got everything for the tube drive who is happy to run from a single phase 220 supply (everything except the 3-phase coolant pump).
 
Ok, like i said, im an electonics idiot, what harm would it cause to try and run it off of a static converter since I already have one. Would it ruin something, or would it just not run properly. I should have those diagrams soon, I am waiting on my manual. Thanks for your help.
 
I talked to the electricial expert at Monarch and he says rotary is the best way to go but a static converter will work but the lathe might not run to it's fullest.
 
Hey Scott. I've heard many times that the tube type 10EE can be run on single phase, but without the coolant pump. Next time you talk to the electronics guy at Monarch, ask
him his opinion on this. I bet a bunch of us would like to know how, but are not qualified enough electrically to figure it out ourselves.
 
Absolutely the tube type can be run single phase - it's quite clear from the circuit diagram that the only think using L3 is the pump, the rest of the system is happy with L1 & L2.
 
I have a 1943 vintage 10EE that I am in the process of rebuilding too. This machine has the motor generator drive (rather than the tube type drawer drive of later years), which also requires a three phase power supply. What I can report from what has been told to me is that a rotary convertor is much preferred over the static type for a load such as a lathe.

I can also report that a VFD drive system (variable frequency drive power supply)is another good way to provide three phase power for your machine tools with only a single phase supply to the line side of the VFD drive. I have done this for years with my Bridgeport mill with no adverse effects.

This is my plan for the Monarch unless I hear from the contrary. I am neither a EE or an electrician so I'm all ears too.

Does anyone out there have an opinion about using a VFD power supply as a source of 3 phase power for the 10EE?

All the best - Dave
 
So long as you stay at 60Hz it shouldn't be a problem. As long as you're doing that you may as well make a rotary phase converter as it'd be cheaper than the VFD (a rotary phase converter is simply a 3 phase motor wired in such a way as to generate the third phase from single phase input - sometimes with capacitors to balance the legs and often with starting circuits to fire them up. You can make one for your use with any 220V 3 phase 5 HP motor, most are made with motors salvaged from the junkheap).
 
I recommend for the electrically inept (yours truly)that you read the article in http://www.metalwebnews.com/howto/ph-conv/ph-conv.html. Once you do, the mystery of three phase conversion is revealed in all it's simplicity. My first converter cost $15 plus a 110 volt light switch and a bag full of capacitors that an old motor guy gave me. My latest is a $75 motor, reconditioned and guaranteed plus $25 for the start and run capacitors. I found out that you have to deal with a good motor shop as the capacitors are bigger than you can find in the Grainger catalog. If you live near Baltimore I can give you my sources for these parts. Home number is 410-666-3842

Regards Bill Bonta
 
The whole idea of the Ward Leonard drive is to accept line power at 60 Hz (25 or 50 Hz in some localities) and to generate: 1) dc at 120 volts for the spindle drive motor's shunt field, about 2 amps, and 2) dc at 240 volts for spindle drive motor's armature (and, obviously, the motor's series field), about 18 amps.

The 3-phase power input doesn't have to be perfect, but it should be within the motor's specifications, particularly the maximum current in the B-phase.

Since the 10EE starts with no load on the spindle, and hence little or no load on the dc generator, a static converter, used as a starter, with additional caps to supply a reasonably good B-phase for the three-phase motor, should work.

Use a clamp-type ammeter to ensure that the B-phase motor current is within limits when going from no spindle load to full spindle load.

Two-phase 10EEs are known to exist (mainly in Buffalo and Philadelphia), and these can more easily be converted to single-phase operation, as a single-phase motor is really a two-phase motor, anyway.

A tube drive 10EE needs very little B-phase power, and then only if it is equipped with a coolant pump (my 10EE was manufactured without a coolant pump).

For a tube drive 10EE with a coolant pump, a 1/2 HP three-phase motor is all that is needed for an idler as the coolant pump, which is the only three-phase load, is rated 1/4 HP.
 
I am looking into getting a 10ee round dial. I have read on this forum that they can be run with a 7.5 hp static phase converter but the lathe will surge unless started up at a low speed and then brought up to the desired speed. I will be getting a rotary phase converter in preparation for a monarch but would i have to get a 7.5 hp or can i get away with a 5 hp rotary phase converter? This is the converter I'm looking into getting, just need to know what would be the best size.

7 5HP 3 Phase Converter Rotary 1 to 3 Phase CNC Built | eBay
 
Dave, Kader's post is over ten years old.

Can't recall anyone documenting application of Peter's design for operating a MG from single phase side stepping any sort exterior phase generation/conversion. The design will work but can't recall a single post or photo of someone cutting apart the triple point connection in the motor field and bringing out the three wires needed to implement the design.

If anyone has done it please chime in.
 
"If anyone has done it please chime in."

There WAS a follow-up post by another. He performed the modification on a conventional motor and then placed the converted motor in a "prony brake" power measurement system (the usual way of testing a motor's true horsepower).

The converted motor did, indeed, produce slightly more than rated nameplate horsepower.

With specific respect to an unconverted M-G machine, Forum member Donie operated his M-G machine for a number of years on single-phase using a "Cedarberg" heavy-duty static converter which was rated 7.5 HP.

It is my understanding that such a static converter employs both a starting means (electrolytic capacitor and a potential relay) AND a running means (run-type capacitor).
 
I did run a 1951 MG powered lathe on a 7.5hp static converter for a while.

If the spindle was started above base speed of the motor, around 1100rpms, the forward or reverse switches would drop out then back in.
In effect, the spindle would surge. If the speed was set at or below 1000rpms the machine would start, and then could be ramped up to full speed once started at the lower.
The drive motor base speed is the rpms when armature and field are at full voltage.

Using what was at hand, a MG unit with a non working DC end, using the AC end as a pony motor, starting that first with the static converter, then running the machine off that, the surging problem stopped. It has been running fine for many years.
An old MG unit makes a nice pony motor, super quiet precision balanced motor. I did remove the large fan blade on the end, the tandem armature has a small fan blade built on, also removed the brush holders from the burned up DC end of the unit.
 
I'm aware of several people running motor/generator 10EEs from static converters. Member 10k recently built one from scratch and I believe that he intends to write an article about it in due course.

Cal
 
The load placed by the 10EE's M-G is about 6 point something horsepower. This exceeds the starting capacity of a Steveco 90-66 potential relay.

However, the Steveco can be setup to actuate an external "definite purpose" contactor with, say, three or four contact sets and the starting capacitor may be distributed more-or-less evenly across those contacts.

A "balanced" converter (equal run-type capacitors from B to A and from B to C) would be an obvious starting point, but a slightly unbalanced converter, with about 60/40 percent imbalance, would probably be closer to the ideal. In such a case, the starting capacitors would be placed across the 60 percent run capacitor during starting.
 
There WAS a follow-up post by another. He performed the modification on a conventional motor and then placed the converted motor in a "prony brake" power measurement system (the usual way of testing a motor's true horsepower).

I recall that. Electrically it works, not sure about motor heating in continuous full power applications however. Still no MG conversions have turned up here. I looked for the connection when my MG was apart for new bearings and such while considering such a conversion. Decided it was too risky to the excellent condition (very low hours, near new condition) MG to start messing with the field windings.

Nicolas, I've witnessed 10 EE MG machines attempting to run off a 5 HP rotary phase converter. Starting the MG is iffy, sometimes it works, sometimes it doesn't and that's on the same machine and setup. There is a distress sound from the converter too. There won't be a problem with a 7.5 HP rotary phase converter. Great price on that converter for a new unit.
 








 
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