I have a discussion with my co -employee
about Y motor with nine leads. This got
a high voltage and low voltage connection,
like a 480/277 v. What my co-employee
is telling me is ,that this motor could be fed by nine cables or wire. Meaning that
this could be supply by 480 and 277 volts at the same time. I said this could not happen,
the leads inside the motor are set , so
that you could choose and do the proper
interconnection inside, so you could
choose between 480 or 277 volts supply.
And the way youu do it is find the terminal point for the supply, and connect it
to a 4 wire supply.

Am I right or am I wrong.

I have no idea what you mean by "And the way youu do it is find the terminal point for the supply, and connect it to a 4 wire supply" but your co-employee is definitely wrong. However, I'm not saying you're right.

[This message has been edited by royta (edited 09-21-2004).]

Are you sure that a couple of these wires aren't for some type of a Thermistor protection system?.

mighty_thor

the nine leads in the y motor are to connect to high or low voltage. you are simply wiring the windings in the motor in series for higher voltage or parallel for the lower voltage. the other windings are internally connected.



[This message has been edited by LAwireman (edited 09-22-2004).]

Thor,
The leads are called "T" leads. You connect them to a 3 wire supply (unless you are counting your equipment ground).

480 volt supply

Phase A-B-C = leads 1-2-3
Splice together 4-7, 5-8, 6-9

That is the standard, you should see a wiring diagram on the side of your motor to confirm this, and give you other connection for multi-voltages if it is designed for it.

Dual voltage motors are not 480/277, they are 480/240. If you look at the wiring diagrams, you will see that the internal motor coils are in series for the 480 volt connection and in parallel for the 240 volt connection. No matter which way you connect the motor, each internal coil sees 240 volts.
Don

It wouldn't be a nine lead motor, and it wouldn't be standard. But in theory you could have a motor where the two possible connections are 480V or 277V, by wye or delta connecting the windings.

Also, with any sort of multiple tap transformer (and the centerpoint splices of the spliced leads are clearly taps in an autotransformer circuit), you can always supply or draw current. Not saying its a good idea, not saying that it would be code. But if I do my figuring correctly, the three splices in a 480/240 V nine wire motor are sitting at 240V apart with a 60 degree phase offset from the 480V supply.

-Jon

Some of you are right about part of this, but I think nobody hit it on the head. The nine leads are basically the ends of 2 sets of 3 windings. On one set, the other end is tied together. The voltage of this motor is 230/460 or nowadays 240/480 usually. It's easier to draw a picture than explain, but I will try. If you had two y's, with the tail end up, the tail would be 1. Going clockwise, the next leg is 2, then 3, etc., spiraling toward the middle. Like this:




The easiest way to remember how to wire it is series for high voltage, parallel for low voltage. For 460 (or 480) volts, you connect your power leads (L1, L2 & L3 usually) L1 to T1, L2 to T2, and L3 to T3. T4 goes to T7, T5 goes to T8, and T6 goes to T9. For 230 (or 240) volts, you connect L1 to T1 & T7, L2 to T2 & T8, and L3 to T3 & T9. T4, T5 and T6 are then tied together. The "T's" that I reference are the motor leads, which are printed on the lead sometimes with the number. If you look at the picture, you can see what I mean by series for high and parallel for low. The high voltage connection has it's windings in line with the other set. The low voltage connection has the two windings pretty much on top of eachother. And, there you go! Let me know if you have any questions about what I typed.

[This message has been edited by kimnjim (edited 09-22-2004).]

Fixing previous post. I had typed a picture in, but it stripped my spaces and was hard to see. Instead, I made one and uploaded it so it was readable.

Moderator can delete this post if he/she likes.

[This message has been edited by kimnjim (edited 09-22-2004).]

By the way, if you want to reverse the direction of the motor, swap any two of the power leads that are connected to the motor leads. Meaning if high voltage, and L1 is connected to T1, L2 is connected to T2 and L3 is connected to T3, swap L1 and L2 so that it is L1 to T2, and L2 to T1. Or, you can go L2 to T3 and L3 to T2. And finally, you could go L1 to T3 and L3 to T1. This works for low voltage too, just make sure you keep the motor leads that are already paired together. Example: L1 to T2 & T8 and L2 to T1 & T7.


[This message has been edited by kimnjim (edited 09-22-2004).]

 
One basic online reference is www.usmotors.com/default_service.htm

In NEMA-standard 9-lead 3ø 230/460V motors, there can be Y or ∆ versions.




[This message has been edited by Bjarney (edited 09-22-2004).]

Thank You, to everybody who replied.
I was just trying to reinforce my
understanding with motors. My experience
from small to large motor, I have not
seen a motor with 2 power supply or
voltage. I was wondering if there a
new method now that it is supply by
2 power supply voltage, and nine wires
coming from this supply.
Now I know that this thing doesn't exist.

You are all right on your explanation.

Thank You.