3 Phase 6 Wires

[Bob La Londe]

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?

 

[Bob La Londe]

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.

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.

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.

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

 

[Baron]

Bob La Londe Inscribed thus:

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

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.

 

[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.

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.

 

[Don Kelly]

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.

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.

 

[Baron]

Bob La Londe Inscribed thus:

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.

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

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.

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.

 

[Baron]

Don Kelly Inscribed thus:

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.

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

 

[Bob La Londe]

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.

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.

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

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.

 

[Baron]

Bob La Londe Inscribed thus:

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.

See Note below:

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.

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.