10EE Drive Retrofit Considerations

It is my objective in this thread to document some of the information, including "gotchas", discovered during the design and implementation of a retrofit drive for my 1956 Monarch 10EE (3 HP, WiaD).

Most of the information I post will be my own. However, some may be paraphrased from other sources (with attribution, of course, where known). Comments and constructive criticism is invited.

240 volt single-phase operation is the goal, with "four quadrant" operation and full support of the 10EE's Reliance 3 HP compound wound motor. After support for compound wound motors is confirmed, support for shunt wound motors (the Ward-Leonard 10EEs) should follow directly.

I'm starting out with a few "baby steps", so please bear with me.

Support for 230 volt dc (armature and series field), 115 volt dc (shunt field) motors appears to be impossible with "open frame" and "packaged" drives operating on 240 volt single-phase power. Several commercial "packaged" drives have been identified which provide this support, but these are three-phase only.

Many drives are actually intended for the more modern permanent magnet ("permag") motors, not the older, conventional motors which are found in all 10EEs.

Some very interesting considerations were recently identified in DANAHER MOTION's publication on their M4000 Series of 5-1000 HP drives.

In the section titled, "Special Motor Considerations", I found this tidbit.

"The Mentor II Drive nameplate is for 240 VDC Armature and 150 VDC field for a 230 VAC 3 phase input. ... The MDA3 Field Current Regulator is set at the factory based upon a typical motor's nameplate data. This means that the drive's settings will get you in the ballpark but they may have to be adjusted to obtain the motor's nameplate speed and full torque capabilities with your specific motor. ... Old MG set motors ... are notorious for uncommon motor nameplates. Note! Be careful when using the Mentor II Drive with a motor what was previously used on a MG set. The motor inductance may be too low and drive tripping and erratic behavior may result. In this case an output choke may have to be installed in the armature circuit."

I am presently proceeding with my design based upon two commercial "open frame" drives which are designed for 240 volt operation. The identity of these drives will be disclosed later.

As usual, these drives only support 180 volts dc (armature; maximum, variable) and 90 volts dc (field; maximum, fixed), are "single quadrant", which do not specifically support compound wound motors, and which do not support "field crossover"/"field weakening" at all.

My initial investigation will be:

1) converting these drives for 288 volt operation, this 288 volts being obtained through the use of an autotransformer (or autotransformers), connected in "boost" mode,

2) converting the first of these drives to develop the required 230 volts dc, 14 amps (maximum; variable) for the armature and series field, and

3) converting the second of these drives from full-wave to half-wave operation in order to develop the required 115 volts dc, 2 amps (maximum; variable, for "field crossover"/"field weakening") for the shunt field.

Peter.


[This message has been edited by peterh5322 (edited 04-28-2003).]

Looks like I'm on the right track.

I discovered an obscure distributor of this particular drive which sells modified versions for *lower* ac input voltages and *lower* phase-controlled dc output voltages to foreign countries, whereas I am in the process of developing a modified version for *higher* ac input voltages and *higher* phase-controlled ac output voltages.

The modification for lower ac input voltage is mainly to the (analog) control section and its (independent) power supply, whereas the modification for higher ac input voltage will be mainly to the input and (phase controlled) output sections.

The revision of the drive I'm working with is slightly different from the current production, but with no other significant differences. Mainly different designators for the various components.

If this modified drive proves out, I'll have to translate the old production component designators to the current production component designators.

Peter.

As long as we are on the topic of drive conversion, I've been considering what
to do if my hydraulic drive (1940 EE) ever gives up.

I don't know what the availability would
be for a similar replacement, but it might be
possible to adapt an automatic transmission
to the job. Depends on whether I can find
one designed for the power range (3-5 HP).

Has anyone else tried something similar, or
have any pointers?

-Dave

Re: Hydraulic drive ...

I think repair or replace "in kind", if you want to keep the machine stock, or convert to a dc drive, are the best options.

If you go for a dc drive, try to find a hand-me-down dc motor and back gear assembly from someone who has converted his 10EE to a 10 HP ac drive (which is provided with no back gear).

Try to get the belt sheaves as well, as Monarch charges $800 for them.

Peter, good idea, but there isn't enough
room for the EE DC motor. Monarch changed
the base casting between 1940 and 1941;
the 1940 model has a compartment for the
drive under the headstock, and a tooling
compartment with collet rack, etc. under
the bed.

Re: Very old 10EEs ...

I forgot about that darn collet rack!

How much space is available for possible replacement machinery ... that is, what are the dimensions of the hydraulic motor and how long are the belts.

Perhaps a "permag" motor is a possibly option.

Which would be nice as these are usually 90 and/or 180 volts ... not 230/115 volts ... and 90 and/or 180 volts is a lot easier to produce and control, for a machine which is to be operated on 240 volts, which I would assume would be one objective.

More info on my replacement 10EE drive ...

My approach, at this point, is to utilize a 240:48 volt, say, autotransformer to apply 288 volts, say, to the input of two basically identical supplies in order to achieve 230/115 volts dc output.

(Each of these supplies are rated 3 HP, because that's what I had available to me on short notice. The field supply could be rated significantly lower, of course, but having one replacement part number has its advantages during the development phase).

The two supplies will be fused differently, however, with the (shunt) field supply being fused at about one-twentieth of the armature (and series field) supply.

Yes, my design is for a (WiaD or later) compound wound motor (with the option for an M-G-type shunt wound motor).

SCRs and power diodes in the input sections of the supplies will be changed to the next higher voltage rating, say, from 600 volts to 800 volts, in order to accommodate the 288 volt input.

Series dropping resistors in the supplies will be changed as needed to provide the supplies' control sections with their original design voltage, also to accommodate the 288 volt input.

The armature supply will be retained as full-wave, in order to provide 230 volts output, while the field supply will be changed to half-wave, in order to provide 115 volts output (which happens to be the nameplate ratings of the armature and field, respectively, of the Reliance and the GE motors I have).

(The motor field could be rewired to 230 volts, and I have that option on the GE motor, but I don't know if I have that option on the Reliance motor).

The original speed control potentiometer will be retained so that "field crossover"/"field weakening" can be achieved, as with the tube drive. (A replacement speed control potentiometer is also under development).

In actual practice most of the original tube drive relays and other components could be retained, but for this "proof of concept" implementation I will be duplicating these functions with other, new components, in order to demonstrate a completely stand-alone, fully functional drive.

(It is my understanding that the other 10EE replacement drive currently under development may be a 180/90 volt drive).

Peter.



[This message has been edited by peterh5322 (edited 05-04-2003).]

Re: Hydraulic drive 10EE retrofits ...

See the thread "Monarch 10EE Drive Conversion" for my comments on retrofitting a dc or ac motor to a hydraulic drive 10EE.

Peter.


[This message has been edited by peterh5322 (edited 05-03-2003).]