There are two sets of windings. You can connect them in series for HV operation (one 'Y') or in parallel for LV operation (two 'Y's).
Chances are there are nine leads brought out so one winding is permanently connected in star and the other can either be connected in series with it or can itself be connected in star and the two star windings paralleled.
----------------------------------
If we learn from our mistakes I'm getting a great education!
Thanks. I have dealt with LV/HV motors before, but never seen this YY and Y. I see it on a 3 phase siemens nord gear motor I just got. Like other motors there is a wiring diagram for LV and HV, however the terminals are not marked. I m posting low resolution pics here, but can email the high resolution.
ok, now I see SOME, thanks. Am I wrong saying this is the worst ever? I can only see some, other wires I see no ident, and some others I see the ident, but i cant read it and there is NO slack. I will try and remove the entire terminal block and electrical box to find out. Who designed this? Every other motor I have even see, the terminals on the terminal block had the identifiers. This is awful. Thanks again.
Unless someone has changed the internal wiring of the motor you should not need to change the wires with the tags.
To switch to 'Y' you would remove the shorting bar on the right vertical terminals and the black wires running from the bottom terminals to the left vertical terminals. Then, connect the corresponding vertical terminals with a shorting bar (or the black wires if you like) as per the wiring diagram.
9 leads are brought out of the motor and land on terminals T1 through T9. U1 and U2 are opposite ends of one winding, V1 & V2 and W1 & W2 are similarly opposite ends of two more windings. U5, V5, and W5 are each one end of another three windings; the other end of these windings is permanently connected in wye internal to the motor.
Take the photo and rotate it 90[°] CCW so that it aligns with the diagram. As connected you have Y-Y with phase 1 connected to U1 and U5, phase 2 connected to V1 and V5, and phase 3 connected to W1 and W5. The shorting bar provides the wye point for the 1/2 windings, while the wye point of the 5/x windings is internal. For Y, you just have the windings in series as shown in the diagram.
The "Y" designation will be to differentiate from a motor that is connected for delta internally. The higher voltage windings are connected the same for wye or delta, but the lower voltage connections are NOT the same. Also the "YY","Y" differentiates from motors that change voltage ratings by changing connections from wye to delta.Common in IEC land, but not possible with a 9 lead NEMA motor.
Bill
--------------------
"Why not the best?"
Jimmy Carter
The motor is wired for 230 volts.
The diagram matches the picture but the picture is rotated.
The shorting links in the picture are between W2, U2 and V2 on the diagram. Remove the shorting links.
The black wires in the picture are between U1 and U5, W1 and W5, V1 and V5 on the diagram. Remove the jumpers.
Now install the shorting links between W2 and W5, U2 and U5, V2 and V5.
The motor will now be wired for 460 volt operation.
For either 230 volts or 460 volts the power is connected to W1, U1, and V1.
Terminal layout.
W5 W2
U5 U2
V5 V2
W1 V1 U1
W1=L3
V1=L2
U1=L1
Power is applied to W1, V1, and U1 for either 230 volts or 460 volts.
Bill
--------------------
"Why not the best?"
Jimmy Carter
ok, I should be looking at the block diagram for placement, didn't someone above say look at the motor diagram? The mtr diagram has V5 in the middle of that terminal block, when its at one end. p
