Hello Everybody
If any of this is already described elsewhere, I would appreciate links to any message threads, or websites that describe what I'm confused about, if it has already been covered.
A little while ago I purchased a number of DC motors and DC drives from a guy who had been "collecting" them to (but had barely began to) match them together. Any that he could repair, he would if he could.
One was already "matched", but now I want to begin to test, and then match as many remaining working motors to remaining working controllers. Many of the motors and controllers I end up not matching together, that won't suit my machines, I may be selling off or finding homes for.
I don't want to burn anything up for a stupid reason like connecting inappropriate motors/drives together. After extensive Googling, (possibly using incorrect terms?) I am having a hard time making sure which numbers need to match, or which numbers need to be "less than", or if the motor specs should be much "less than", and when.
SO:
-I would like to learn how to match appropriate motor specs to drive specs
-I would like to know the importance of DC motor "armature voltage" vs "field voltage" (unless I REALLY don't need to know)
-I would like to know how far below the Driver-voltage can the motor be, or does the motor-voltage need to be higher than the driver-voltage? Or does it need to be exact?
-Is just wiring up possibly-correct motors and drivers together and powering them on a reasonable way to check them? or should I put the Fluke Meters and look for certain readings on motor leads or driver connections first, somehow?
-What do I do when the DC-Driver has no specs, or limited specs? It has been VERY hard to find vintage PDF's of brochures, manuals, catalogs to glean this information, even for Bodine, who is still in business (I called them!). Maybe I should try calling them again?
-I heard that the TYPE of DC motor might effect driver choice, as regards matching a drive to either a Permanent-Magnet, Series, Shunt, or Compound motor.. Is this true?
I can post pics of more motor spec-plates and driver spec-plates (if there they have one)
-All of the motors in question are permanent magnet DC motors, Porter Peerless, Dayton, and one really nice Leeson (**this is one of the first I want to match up, it's new**)
-I have a few different Reliance IMPAK "V-S" drives- one non-"V-S", a nice Bodine drive, and a Dayton drive.
For instance..
.
One of the IMPAK drive's plate says:
1.5 HP
AC 230v 9.5 A. RMS. 50/60 HZ.
ARM 180v 7.5 A. AVE.
DC FIELD 100V. 2A. MAX
.
A Leeson Motor plate says:
1.1kW (1.5 HP) F.F. 1.05 D.C. AMPS 7.0
.75kW (1.1 HP) F.F. 1.40 D.C. AMPS 4.9
RPM: D.C. Volts: 180
(This is a nice motor, but is "metric" or something, and does not give NEMA, but IEC numbers)
Do these go together?
I attached pics of these plates to this post.
... So the most powerful DC motor attached to this should be above or below 100V?
I am assuming the motor should be less than 2A at that voltage.
Thank you for reading! This was the SHORT version of this post!
Bernie
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B IMPAK V-S 8C57D 1-5 hp_.jpg
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MB LEESON 180V 3-4 rpm _s.jpg
Happy to help.
Regarding "field" specs - you got it.
Testing the motor - Motor windings generally fail open or short. Hang an ohm meter across the motor terminals to check this. Give the shaft one slow rotation by hand, so that you check each of the commutators and rotor windings. Resistance will change a bit as the brushes alternately make contact with one or two commutators, but should never go short or zero. You should also check the motor brushes (remove them one at a time, and replace in the same orientation they were originally). Basically, you're looking for lengths below 1/8" (or 1/4"?), which would indicate the brushes are ready for replacement. Once you've done this, you're ready to try the motor under power.
As for the power supply, as long as the maximum armature voltage isn't too far (~20% or so?) over the motor voltage, and the maximum current rating is equal to or greater than the motor's rated current, the easiest thing is to just go ahead and connect them and try them out. If the voltage is correct, the motor will only draw the current it needs. If the motor runs, both the motor and supply are OK. If the motor doesn't run, check the armature voltage. If it's zero (and you've checked the motor for shorts), the supply may well be bad. Just be careful - 180 volt is dangerous!
Unless the motor has a short, it shouldn't damage the supply. If it's open, it just won't run. And as long as the supply's max voltage is close to the motor's, the supply shouldn't damage the motor.
Disclaimer - I'm pretty sure this is all valid, but I'm not an electrician. And yes, there's lots of fine details and rabbit holes that can complicate things. But this should get you started. PS - @Bi11Hudson is very knowledgable in all things electrical. If he decides to join in, his post will be worthwhile reading in detail. And ANY difference(s) between us should ALWAYS be decided in his favor!
Happy to help.
Regarding "field" specs - you got it.
Testing the motor - Motor windings generally fail open or short. Hang an ohm meter across the motor terminals to check this. Give the shaft one slow rotation by hand, so that you check each of the commutators and rotor windings. Resistance will change a bit as the brushes alternately make contact with one or two commutators, but should never go short or zero. You should also check the motor brushes (remove them one at a time, and replace in the same orientation they were originally). Basically, you're looking for lengths below 1/8" (or 1/4"?), which would indicate the brushes are ready for replacement. Once you've done this, you're ready to try the motor under power.
As for the power supply, as long as the maximum armature voltage isn't too far (~20% or so?) over the motor voltage, and the maximum current rating is equal to or greater than the motor's rated current, the easiest thing is to just go ahead and connect them and try them out. If the voltage is correct, the motor will only draw the current it needs. If the motor runs, both the motor and supply are OK. If the motor doesn't run, check the armature voltage. If it's zero (and you've checked the motor for shorts), the supply may well be bad. Just be careful - 180 volt is dangerous!
Unless the motor has a short, it shouldn't damage the supply. If it's open, it just won't run. And as long as the supply's max voltage is close to the motor's, the supply shouldn't damage the motor.
Disclaimer - I'm pretty sure this is all valid, but I'm not an electrician. And yes, there's lots of fine details and rabbit holes that can complicate things. But this should get you started. PS - @Bi11Hudson is very knowledgable in all things electrical. If he decides to join in, his post will be worthwhile reading in detail. And ANY difference(s) between us should ALWAYS be decided in his favor!
Hman, markba633csi,
Thank you SO much. What you are both telling me makes sense..
I worked with an electrician in college, wiring businesses and houses, but my learning curve understanding how circuits work etc is pretty steep t this point, hahah
Maybe I will nudge @Bi11Hudson, even if he doesn't have time to answer for a while, so anyone searching this in the future will get the best scoop they can (and for ME hah hah)
I think you have me off and running, and I cannot thank you enough!!
I will ask, just to keep working on my learning curve (so whenever anyone has time, no rush):
What makes so many of these drives show up on auction sites so inexpensively? I guess people like me don't know how to test them, so they are just unloading them? It would seem a worthwhile risk to purchase a few and get one or two good ones, and maybe repair another
I will post my updates in the next day or so
Thank you!!
Bernie