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3 Phase 6 Wires

I have a Leland 6273 3 phase 240 V motor I am trying to figure out how to hook up.

It has 6 black wires coming out of the motor.

It also has 2 much smaller brown wires coming out that were just tied out of the way to the lifting ring. I suspect those were for a tach or possible a heat sensor.

It just has paper labels on the black wires, and they look like they were put on by somebody who tried to figure out the motor in the past. They do not match up with any of the three phase wiring numbers/ letters standards I've been able to find. I want to hook it to a VFD for testing. Since the data plate says it will operate from 6-130 HZ and lists a range of RPM from

96 to 3680 that tells me was probably intended to operate off of VFD in the first place.

Is there any practical way using a meter to determine which wires to pair up to connect to 3 connections on the VFD?

Reply to
Bob La Londe
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Put your own unique identifying tags on the various leads coming out. Find which leads connect to each other. We can go on from there.

If you know your stuff, take a variable transformer (variac) to excite various windings with a low ac voltage (12 or 24 volt control transformer). Measure the voltages across the various coil to get an idea of ther electrical orientation.

Reply to
Salmon Egg

The wires are in groups of 3. Any 2 in the first group read about 20 ohms. Any 2 in the second group read about 2 ohms.

I read something about that already. Seems one guy use a small DC power supply like a battery and measures the direction of deflection on adjoining windings when he removes the power source. Sounded like it would be easy to get confused that way, but I may be reduced to that.

The data plate reads:

Leland Electrosystems Inc Model 6273 Serial TX43042 FR 215 HP5 HZ 3/130 C Temp rise Cont. NO.71 RPM 96-3680 Class H insulation

Reply to
Bob La Londe

Bob La Londe Inscribed thus:

You might find that its dual voltage, 240/480 3Ph, and delta connected. In which case wire one lead of one set to each phase, if the motor runs the wrong way for you, just swap any pair. Check that there is no connection to the frame from any wire first. Put the other three wires into a piece of three way chocolate block to insulate them. Just to test I would start with the higher resistance winding which is probably for a 480volt feed.

Reply to
Baron

Ok... I got it figured out. Mostly... Its got an independent fan motor. Doh! Had I been a bit more observant I would have seen that myself, but somebody in another group pointed out the possibility, and commented on the probability because a motor turning only 96 RPM at 3 Hz can't possibly be turning a fan fast enough to cool itself.

It was easy enough to check. I spun the fan and held the brake disc on the motor with my other hand. Wheeeeeeee!!!

It has six primary leads because there are two motors.

I suspect the 2 smallish brown wires are a thermal sensor. Not sure I can test it except maybe... to wire up the motor and not the fan motor. LOL.

Reply to
Bob La Londe

There is nothing said that indicates Y or delta connection and, for dual voltage, the 20/2 DC resistance level doesn't strike a bell. Even at 480V, a 20 ohm line to line DC resistance appears quite high for a 5HP motor. I suspect that the 2 ohm windings are the main windings. However, without the actual motor specifications, this is all conjecture.

Reply to
Don Kelly

Bob La Londe Inscribed thus:

Very true. The same applies to the fan motor if it runs the wrong way. Just swap any pair of its wires.

I had overlooked the possibility that there was a fan motor in there ! Sorry. :-(

But please use an insulation tester (megger) and make sure that there isn't any leakage to the frame from any wire group. If the motor has been stood for a while damp can cause any leakage current to be higher than normal. Just run the motor without the fan to get it warm enough to drive off the damp. I've seen VFD's damaged because of high leakage current to the earthed frame. Sometimes these motors come onto the market because of this and its cheaper to replace rather than repair it.

Anyway I'm glad that you've cracked it.

Reply to
Baron

Don Kelly Inscribed thus:

I agree. I faulty assumption on my part ! I missed the vfd rating indicating that it would have a fan motor.

Reply to
Baron

Well, its been sitting in my shop in SW Arizona for a year, so I suspect it has probably dried out quite a bit. I will check for impedance to ground before running the motor. Probably have to get a different VFD if I run the motor to full power. It was originally used for 3 in 3 out for speed control, but I do not have 3ph available, so the VFD will not be able to handle the motor if its loaded much beyond half capacity. (I do have (and have read) the manual for the VFD). I need to break down and get a second VFD for the fan motor anyway. Eventually I suppose I should just put a 10HP rotary phase converter in my shop.

The stupid part is I pulled the back cover to check the fan since there was a dent in the cover. The fan motor is fully visible. Its just not what I expected to see so I didn't see it. I didn't even realize that the output shaft (still connected to the mechanical load) took more force to turn than the fan. DOH! LOL. Once I realized what I was looking at I couldn't believe I didn't see it to begin with.

Reply to
Bob La Londe

Bob La Londe Inscribed thus:

See Note below:

I wish I had a $/£ for every time I've looked at something and simply not seen it.

Note: You could test the fan motor on single phase by using a capacitor to feed the third wire. Try one from a fluorescent light fitting or anything similar like a washing machine motor. Small motors tend to be fairly intolerant of actual value.

Reply to
Baron

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