Purchasing a Monarch 10EE Round Dial

Robert, I don't know what 2 phase is....I'm thinking you mean 3 phase? No matter what it is, you can make it run. Mine is 3 phase 440 and I'm running it with my standard residential service. Congrats on your purchase. It looks like you have your work cut out for you. If you happen to have any extra contactor coils in the mix, I would be real interested in buying one from you. I've been using my machine with only forward spindle rotation for a couple of years now. Good luck with your project.

Chuck
 
I stand corrected. I googled 2 phase and learned that it does exist although it's not common. I'll be interested to hear about it from someone that knows electrical systems.

Chuck
 
The following applies to North American electrical systems....

Two phase is not the correct terminology and sometimes, the terms "split phase" or "split leg" is used. The 220 power that we are familiar with is what comes into our home service panels and it consists of one neutral and two "hot wires". Somewhere in the neighborhood, there is a transformer with high voltage coming into it. They put a winding next to the core and it induces 220 volts into the winding. The two wires from that winding are the two hot wires that enter your house. If you measure the voltage between those two hot wires, it will read 220 volts. In the middle of that winding, they put a "center-tap" which is just a wire that connect to the center of the winding. That wire is the neutral that is brought into your house. If you measure between the neutral wire and any hot wire, the voltage is 110 but, one with respect to the other is 180[SUP]o[/SUP] out of phase. Without a significant description of phasor mathematics and something called "complex numbers", it would be very hard for me to describe in other terms why the phase change occurs but, suffice it to say, it does indeed occur.

BTW, the terms 110, 120, 220 and 240 are a little confusing. 110 and 120 are the same really; it's just that the power company is allowed to vary the voltage under different circumstances and it could be somewhere in that range. The frequency (60 Hz in North America) will not change and if it ever does, there are serious, serious problems going on in at the generation facility -to the extent you will probably see a bright flash coming from the facility. -Basically, it does not vary and if it does, it happens simultaneously all through North America. The entire system is synchronized.

Ray


Chuck K said:
I stand corrected. I googled 2 phase and learned that it does exist although it's not common. I'll be interested to hear about it from someone that knows electrical systems.

Chuck
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Ok Ray, I'm kind of an idiot when it comes to electricity. Are you saying that 2 phase 220 is what I know as single phase 220? My understanding of 220 single phase consists of 2 hots and a ground. (red, black, and green)

Chuck
 
Ray it is a 4 wire 2 phase 220 volt motor generator. It is an obsolete power type except in certain places on the east coast. It is completely different from split phase. Robert
 
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What I'm conveying is that the residential 220 volts that come into our house are technically called "single phase" but sometimes referred to as "split leg" or "split phase". The originating power on the feed side of transformer is single phase (actually, it is coming from one of the legs of a massive 3 phase transformer that's located at your local power substation) but, through the trick of center-tapping the output side of the transformer, you can split that single phase apart by 180[SUP]o[/SUP]. When it returns to the transformer, it recombines into single phase. Once again, the mathematics to show this is very time consuming and I consider it a failure on my part to not be able to describe it in understandable terms -and I don't know of anyone whose managed to describe it in non-mathematical terms.

Anyhow, yes, we get 220 single phase (2 hots and a neutral) and it's single phase. Measuring between the neutral and a hot, you get 110 and measuring between neutral and the other hot you still get 110 but, it's 180[SUP]o[/SUP] OOP with respect to the first one you measured. You can see this easily with an oscilloscope.

Ray


Chuck K said:
Ok Ray, I'm kind of an idiot when it comes to electricity. Are you saying that 2 phase 220 is what I know as single phase 220? My understanding of 220 single phase consists of 2 hots and a ground. (red, black, and green)

Chuck
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Four wire 220 is a totally different animal! I do not think it's available commercially and if it is available, it might be part of a private generation system that is not connected to the North American grid. It's possible a railway system or some massive industrial complex needs such power and they generate it themselves or, pay the local power company to produce it specially for them. It is not common at all that I know of but, I am not currently involved in industrial electronics. My initial pedigree (dual major) was in traditional electrical engineering and physics.

Ray

vettebob said:
Ray it is a 4 wire 2 phase 220 volt motor generator. It is an obsolete power type except in certain places on the east coast. It is completely different from split phase. Robert
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One final note... The neutral wire that comes into your house may or may not be grounded to earth at your house. It may be grounded to earth at the location of the transformer. The rules on this vary in different locations and it depends on many things pertaining to the transformer equipment used by your local power company and the distance it's located from your service entrance panel and believe it or not, depends on the soil conditions in your area. I believe these days, most houses have one (and only one) connection from that neutral wire of your service panel to earth ground. Having two connections is NEVER a good thing. -Again, I am not totally familiar with the "rules and ordinances" aspect of commercial wiring. You need to check with a certified electrician in your area.

Ray
 
Ray,

There is such a thing as 2-phase power. It's not single phase, i.e. standard household wiring. It's not 3-phase. It has two phases, 90 degrees apart, whereas 3-phase has 3 phases, 60 degrees apart. In the late 1800's 2-phase generators were installed at Niagara Falls and 2-phase power continued in the area until some time in the 1950s. 2-phase systems are usually 4 wire systems. Engineers figured out fairly early that you could get smoother power and use fewer wires by going to 3 phases. But by that time there was already an installed base of 2-phase generation, so the system continued. I've seen one other 2-phase 10EE crop up in the last decade. Josh, over in the Van Norman & Cincinnati forum, is rebuilding a Cincinnati Toolmaster mill that was originally 2-phase.

According to this, PECO still provides 2-phase service in Philadelphia:
http://en.wikipedia.org/wiki/Two-phase_electric_power


Robert,

A "Scott T" transformer connection can, in theory, be used to run a 2-phase motor from 3-phase. However, I don't know if it's going to work from a rotary phase converter. You may be able to find a surplus "Scott T" transformer from a piece of 2-phase equipment that been pulled out of service; check electrical surplus outfits in the Niagara Falls area. (You would be looking for about a 5kW transformer.) Is there any chance that the seller has one?

The good news is that with your machine is that a relatively inexpensive solid-state DC drive can be put together to run the original DC spindle motor. One option is to use a single-quadrant DC drive for the armature and a simple DC supply for the field. The DC control panel and the big rheostats would continue to be used. The DC control panel will provide reversing, anti-plugging, dynamic braking and field acceleration functions; the field rheostat would provide field weakening to get the motor above base speed. There is a gentleman in the UK who's doing just that.

The DC control panel on your machine is the type used on square-dial machines. You either have a very late model machine or one that's been updated.

The big box on the front of the base, under the tailstock is probably a rheostat and other wiring for a rapid reverse feature. I’ve only seen one other motor-generator 10EE with the feature. It works with the ELSR so that the reverse speed can be set higher when threading to speed up operations. There is going to be some unusual wiring associated with it and I do not know of a factory wiring diagram for it.

What is the serial number and build date of the machine?

Cal
 
Cal it was manufactured in February of 1944. I was thinking about going to a solid state drive to remedy this. The lathe does have the rapid reverse feature. If some one had a motor generator that didn't work I could probably swap in the motor part into mine. The mg was rebuilt in 05 or 06 and the Lathe has sat around for probably the last 4 years. Could you send me a link to the guy going solid state. If I go solid state I want to be able to maintain the elsr features. I thought about the kblc boards but there is probably better out there now days. Robert
 
This is just a educated guess but I would say the MG set is to use 2 phase power to run a standard motor.

Vettbob and Cal Haines are closest to the truth. Two phase is only available back east and I have read about it but never seen it in use. Was very popular or at least used quite a bit in the Ohio PA area in large manufacturing plants. The National Electric Code has very little to say about it. I have heard of the Niagara Falls connection in other sources.

Grounding of neutrals. Neutral conductors are the electrical ground of a system. The green or bare wire is the equipment ground of a system. For some time they were allowed to be used for dual use by code such as in ranges, ovens, dryers and such in residential applications. Since about the 2006 edition of the code they are once again separated and must remain so. You no longer have three wire cords going to ranges and dryers. Now all cords and recps and associated wiring must be four wire. The change over in existing locations will come via changes and remodels to the premises when inspected by a Electrical Inspector. So when you add a circuit to the patio and have to rewire the range or dryer or both, don't be too surprised.

Every neutral is grounded at the main service entrance panel. This is the only location where the green and white wire may come together. The transformer on the pole or pad mount is grounded to the neutral. If you look at the pole where the transformer is mounted there is a plastic pipe or wood cover coming down the pole. This is to provide physical protection for the ground wire. There generally is no ground rod. Once the wire gets below ground level it is wrapped around the butt of the pole six to eight times.

The neutral conductor carries the unbalance of load between the two phase conductors. If you have two 120v devices. A phase draws two amps, the second draws two amps. The neutral carries zero amps. Yo could disconnect the neutral and the circuit could not care less. When measured at the source. If you have two 120v devices. One draws two amps, the second draws three amps. The neutral carries one amps. Now here is the real zinger. In the second scenario if the neutral connection goes away for any reason you loose the votage refernce to ground for the system. This means the voltage on phase A will be 160 volts and the voltage on phase B will be 80 volts. Any other 120v items in the system connected to phase A will likely burn up (excess voltage) and any 120v items on phase B will get dim and maybe cease to function. (under voltage) Eitherway it is not a good thing. Either way it is very important to have a solidly grounded neutral in the system at the main distribution panel. Take a lamp holder and wire Phase A and neutral to it. Take a second lamp holder and wire phase B and the same neutral to it. Put in two 60 watt lamps. Turn it on. Now disconnect the neutral, besides maybe a flicker nothing changes. Now de-energize the power and replace one 60 watt lamp with a 100 watt lamp. Restore power, everything should be fine. Now disconnect the neutral. Fun huh? While doing all this clamp an amprobe on the neutral and see what it reads.

Tried to explain the best I could without math. I am not strong on math by any stretch but isn't it funny how important it is to both electricity and machining? Wish my teacher would have said "You will use these trig formulas calculating angles for gears." Hell I would have probably paid attention.
 
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