6 wires 3P motor with no diagram for connection 240 or 480?

[teal854t]

I bought the used machine with 11KW, 3P motor. Thinking that it's run by 480vac. We were getting ready to try it and just to make sure it is wired to 480 configuration I opened the motor terminal cover to check the connections. There a plate but the 480 is scratched, no 240/480 wire configuration diagram. It has 6 wires coming out fron motor. 2 wires to each phase, 3 pairs of wires to each phase. How can I determine if the motor is set up for 240, 3p or 480, 3p?
I was thinking of hooking up 240, 3p to it and measure the current and compare with calculated value.
Will the speed change fron 240 to 480? I know speed is determined by cycle and poles.
Thanks

 

[iwire]

Do the leads still have identfication?

T1, T2, etc.

 

[electricman2]

The 3 phase dual voltage motors I have seen have 9 leads. 6 leads sounds like single voltage.

 

[teal854t]

There's no numbers. If there's number how can I find out?

 

[Onitram]

Seen this type of motor, mostly on european machines, food machines, but they had terminals on them. They can be wired DELTA Or WYEN , for Y tie three ends togheter ,then the 3 wire remaining will be line 1,2,3 380 volts. For DELTA wire them in series and the 3 tie points will be Line 1,2,3 240 volts. check windings with a ohm meter to identify first, run motor without load and check amperage on all 3 lines that they are the same. hope it helps............

 

[teal854t]

Thanks Onitram, we have few European motors and they have 6 wires. Y for high voltage and Delta for low voltage. If the terminal letters u, v, w are not there I can ohm them out and find each winding: u, v, w. How do I know which side is u1 or u2, v1 or v2, w1 or w2?

 

[benaround]

It will make no differince witch end of the windings that you use.

 

[Onitram]

It will make no differince witch end of the windings that you use.

seen in a book sometime ago how to identify 9 lead motor when id number faded away, it was done in steps with motor enrgized short time, if i find it iwill reply.

 

[don_resqcapt19]

Frank,

It will make no differince witch end of the windings that you use.

Yes it sure will. If the wires from one coil are reversed in respect to the others the resulting magnetic field will be in oposition to the the motor rotation.
Don

 

[DGrant041]

Re: 6 wires 3P motor with no diagram for connection 240 or 4

Re: 6 wires 3P motor with no diagram for connection 240 or 4

I bought the used machine with 11KW, 3P motor. Thinking that it's run by 480vac. We were getting ready to try it and just to make sure it is wired to 480 configuration I opened the motor terminal cover to check the connections. There a plate but the 480 is scratched, no 240/480 wire configuration diagram. It has 6 wires coming out fron motor. 2 wires to each phase, 3 pairs of wires to each phase. How can I determine if the motor is set up for 240, 3p or 480, 3p?
I was thinking of hooking up 240, 3p to it and measure the current and compare with calculated value.
Will the speed change fron 240 to 480? I know speed is determined by cycle and poles.

Don is correct, you can't relay on an ohm meter alone. I've never wired a motor that didn't have ANY markings. Sometimes the markings are where the wires come out of the motor housing. You also said you were just checking to make sure it was wired for 480 V. Did the electricians just "guess" or did they find the wire markings?

"11kw" tells me that it's a Euro machine. Name plate should have all the 50 hz ratings.

Like the others have said, if it is dual voltage 200/400, 240/480V, you should see that on the nameplate and it should be connected WYE. Line connects 1, 2, 3 to u, v, w respectively. The other three connect together what ever they call them.

Let us know what you find.

 

[james wuebker]

Just got done wiring a Siemans 5 hp motor with 6 leads. Either 240 or 480.
Jim

 

[oliver100]

If the motor appears to be from Europe 380/220, the closest voltage for usage in US should be 3Phase 208 V. Motor windings should be DELTA connection.

In any case, the termination must be identified for each phase (T1, T2 ..).

A practical method for identification is with a battery and a voltmeter.

 

[don_resqcapt19]

Jim,

Just got done wiring a Siemans 5 hp motor with 6 leads. Either 240 or 480.

How does that work? I thought that the two voltages on a 6 lead motor had to vary by a factor of 1.73 to 1 and not 2 to 1. It is my understanding that you change the voltage on a 6 lead motor by connecting in a wye for high voltage and a delta for low voltage.
Don

 

[DGrant041]

Jim,

Just got done wiring a Siemans 5 hp motor with 6 leads. Either 240 or 480.

How does that work? I thought that the two voltages on a 6 lead motor had to vary by a factor of 1.73 to 1 and not 2 to 1. It is my understanding that you change the voltage on a 6 lead motor by connecting in a wye for high voltage and a delta for low voltage.
Don

No. The equation stays the same for both connections. (I would post a picture here but I just keep getting errors.)

HP = E * I * %Eff * pf * 1.73
746

(Ugly's p 19 - 2002) I love that book!

6-lead motors are the norm where I'm from. It's the 9- and 12-lead motors I have to watch and RECHECK before I'm done.

 

[don_resqcapt19]

DGrant,
The horsepower formula has nothing to do with the voltage connections.

What are the connections with 6 leads? That is only 2 leads from each coil. The only way that I can think of to make dual voltage three phase motor work with 6 leads is either a wye connection for the higher voltage supply voltage and a delta connection for the lower supply voltage. If this is how these motors are connected, then the voltage ratio has to be 1.73 to 1.
Don

 

[DGrant041]

Don-

This would be a lot easier if I could add a picture but I just keep getting errors. :?

Delta connected
Vph = Vline
Iph * 1.73 = Iline

Wye connected
Vph * 1.73 = Vline
Iph = Iline

Even though the Vph and Iph change for Delta and Wye connections, Vline is set respectively. Otherwise the motors would be 240/277V. But motor nameplate ratings are based on standard line supply voltages 240/480. . .Actually, 230/460 because the assume a voltage drop across the line.

Did I answer the question? It's really hard to do with just word and hoping others have the same picture in their head.

Again, I reference the Ugly's book p 19. Also, p. 40 & 41 have the different motor circuit charactoristics for 230/460 Vac.

 

[don_resqcapt19]

DG,
Tell me how it is connected. I would expect that for high voltage three of the leads are connected together and the other three connected to the lines. For the low voltage I would expect that there would be two leads connected to each line. If that is the case, then it is a wye and delta setup and if the high voltage is 480, the low voltage would have to be 277. Does the nameplate list a lower hp for the low voltage connection?
http://apps.motorboss.com/connections/438252.pdf
I see no way to get a 2-1 voltage rating without two coils per winding.
Don

 

[DGrant041]

Don-

Yes, you found it! I searched all over for a motor connection diagram with no luck! Did you have any luck posting a picture, or is it just me?!

I would expect that for high voltage three of the leads are connected together and the other three connected to the lines. For the low voltage I would expect that there would be two leads connected to each line. If that is the case, then it is a wye and delta setup and if the high voltage is 480, the low voltage would have to be 277. Does the nameplate list a lower hp for the low voltage connection?

Yes, Wye is for High voltage and Delta for Low. BUT motor ratings are based on the supply voltage (and current), not the phase voltage. For 480V Wye connection, phase voltage would be 277. For 240V Delta connection, phase voltage would be 240. The square root of three difference is in the phase voltage not the line voltage that the name plate is based on. HP is constant in this case.

Is that any better? I was thinking about trying to draw a diagram with | \ and coils using )'s and u's but it didn't really turn out. :roll:

 

[don_resqcapt19]

DGrant041,
Each winding or coil has a voltage rating. The actual voltage that each coil sees in operation depends upon how the motor is connected. If the motor is connected delta then the coils see the full phase to phase voltage. This would be the low voltage rating of the motor. If you connect the coils in a wye, then each coil will only see the phase to phase voltage divided by 1.73. This would be the higher rated voltage. This cannot change. The actual ratio must be 1 to 1.73. I can only assume that if the motor is nameplated at 480/240 and is a 6 lead motor that the coils are over designed so that they can withstand the 277 volts that will be flowing through then when the motor is supplied by 480 volts and wye connected.
Do you have a manufacturer and model of a motor of this type?
Don

 

[DGrant041]

Sorry Don, most of my searching has come up missing the number of leads a motor has.

I'm guessing that's because most people specify things on the name plate but the number of leads depends on how the manuf'r choose to connect it. At my old job, I had over a hundred motors to choose from--here I have none. If anyone else has any info, feel free to post. I'm out of resources.

Believe it or not, I agree with most of what you are saying but you're still confusing the voltage across each phase with the voltage rating of the machine. If you just take a 480V (or 460V) Wye connected motor, each phase winding would be 277V. I think it's very hard to find a nameplate rating like this although I'm sure they do exist. Also, if motor ratings were actually phase ratings then you would have to multiply these values by 1.73 to get the HP and KW equations to come out right.

Sorry I couldn't be of more help.