Thread: Baldor motor, single or 3 phase? I'm confused

Gday All.
I have a 1/2HP Baldor motor. It has two id labels. One on the main body and another on the terminal box cover.
The one on the main body says its single phase, dual voltage.

baldor 001.jpg

However the label on the terminal box says its 3 phase.

baldor 002.jpg

It has 6 wires coming out of the interior and they are numbered 1,2,3,4,5 ,8

baldor 003.jpg

As it is atm wire numbers 2,3 &8 are joined together.
numbers 4 & 5 are joined and number 1 is on its own.
I salvaged this from a bit of equipment in a dumpster some time ago and its just been in the shed since. I believe the terminal box cover is original and not from a different motor.
Can someone with more knowledge of these things explain to me what it all means please? Does it mean it can be wired to run on 240V single phase and also be configured to run on 3 phase?
Thanks in advance
Peter

Looks like a 3p motor kludge wired to run on SP. Can’t imagine it being very efficient. Whats the piece of gear? Maybe it doesn’t need much power.

Originally Posted by BobL

Looks like a 3p motor kludge wired to run on SP. Can’t imagine it being very efficient. Whats the piece of gear? Maybe it doesn’t need much power.

Bob.
No idea what the equipment was, it was also some time ago. Id be happy if it could run on 3 phase.
peter

First of all I would check to see if the 3 coils all had the same impedance/resistance. Then If it was me I’d try running it on a VFD. Slow start and Current limited to ~ half the rating. Add an ammeter and watch the current as it gets to full speed. Let it run an monitor temp and see how it goes. The VFD will look after itself and also protect the motor.

First of all I would check to see if the 3 coils all had the same impedance/resistance. Then If it was me I’d try running it on a VFD. Slow start and Current limited to ~ half the rating. Add an ammeter and watch the current as it gets to full speed. Let it run an monitor temp and see how it goes. The VFD will look after itself and also protect the motor. If you want to run it direct from 3P it would need a current reg of some kind.

Originally Posted by BobL

First of all I would check to see if the 3 coils all had the same impedance/resistance. Then If it was me I’d try running it on a VFD. Slow start and Current limited to ~ half the rating. Add an ammeter and watch the current as it gets to full speed. Let it run an monitor temp and see how it goes. The VFD will look after itself and also protect the motor. If you want to run it direct from 3P it would need a current reg of some kind.

Thanks, I'll do some more research on it.
peter

Originally Posted by bollie7

Gday All.
It has 6 wires coming out of the interior and they are numbered 1,2,3,4,5 ,8

baldor 003.jpg

As it is atm wire numbers 2,3 &8 are joined together.
numbers 4 & 5 are joined and number 1 is on its own.
I salvaged this from a bit of equipment in a dumpster some time ago and its just been in the shed since. I believe the terminal box cover is original and not from a different motor.
Can someone with more knowledge of these things explain to me what it all means please? Does it mean it can be wired to run on 240V single phase and also be configured to run on 3 phase?
Thanks in advance
Peter

From this picture and your description of the wiring, I can only see two connection blocks there. This would suggest that it expects a single phase supply ! I would make a temporary 240 volt feed to those two points and test it. I would also use an earth clip to the frame as well, just in case there is any leakage to the frame.

If it wanted three phases there should be three connection blocks.

This pic may help. I found the specs for that motor on the ABB site (who own Baldor now) https://www.baldorvip.com/Product/In...rnal/?id=L3504

Rick

Opera Snapshot_2020-03-14_174805_www.baldorvip.com.png

I'll preface by saying I'm not an electrician or anything related.
I look at the data plate and it is clean and is in good condition. The paint on the motor also looks relatively clean as does the inside of the wire connection box. The cover looks a little beat up and dirty, corroded around the screws and the screws themselves are looking well used too. That leads me to conclude that the original cover was lost and replaced with an old one because it was handy and fit. I believe the motor is a single phase.

Pete

Its a single phase motor and in its current connection its 230v. Dont try and connect it as a 3 phase, it wont work and could damage it. Worked with baldor for years in food and manufacturing industries. Very good motors but expensive. You dont show a full picture of it but there should be a capacitor cover on it. Any motor with a capacitor is single phase. Second photo shows what looks like the cover at top. Agree with previous post that the junction box lid has been changed out with wrong one.

From data sheet its a capacitor start.

https://www.baldor.com/catalog/L3504#tab=%22specs%22


https://www.baldorvip.com/Product/In...rnal/?id=L3504

You may want to test the motor for a while on the bench before using it.
Given that you will be running it at 50Hz, it may run hotter. It will run at a slower RPM than listed on the name plate.

Good luck
Regards,
Paul.

Thank you for all the replies. I should have searched for information online myself and normally, I would have done, but for some reason I didn't do that on Sat night. DUH Must have been a seniors moment.
Yes the motor does have a capacitor. I've always thought it was single phase, its just that the label on the terminal cover threw me.
I might find a use for it one day.
thanks
Peter

Peter,

Did you happen to look at the capacitor and note what value it is?
I have a Baldor 110/240v motor (3/4HP) fitted to my lathe. This was fitted with a 150 microfarad cap but it was almost certainly not the original.
I found it had quite poor starting torque and tried a 250 mic cap I had on hand and that seems much better.

I would be interested to see what is fitted to your motor (slightly different but I am interested in what value it is) . I found the wiring diagram online readily enough but the start cap value has eluded me.

Ray

Ray.'
No I didnt but I can.
PM sent
Peter

Hi Peter,

Originally Posted by bollie7

Ray.'
No I didnt but I can.
PM sent
Peter

Is the capacitor size secret ?