Problem with Motor Starter

I just rewired my wood lathe from 440v to 220v three phase. I also
rewired the transformer for 220v primary to 115v secondary. I also
rewired the coil/ contactor for the new voltages. I also rewired the
motor for 220v operation.
I tried the lathe originally wired for 440v on my 220v phase converter
and it ran fine somehow? After I rewired everything I cannot get any
voltage to the motor across the coil but the contactor does lock shut
and stays that way until the stop button is pushed. I also changed the
heaters from 1.6 amp to 3.2 amp heaters.
I checked the secondary on the transformer and it is only putting out
107v. The coil requires 115v. My converter is not balanced and the
voltages are a little low on 2 of the legs. The wild leg is around
240v. I thought that I might move the wild leg to power the transformer
and up the voltage. I just thought that the coil would still operate on
a little lower voltage than it required.
The coil has 2 wires coming off of the terminal block L1 and L3 that go
into the bottom of the coil. The top side of the coil can be wired for
115v or 220v. I assumed the coil must be wired for 115v operation so I
wired it as the schematic on the coil showed. On the 220v wiring
schematic for the coil it showed line to terminal 1 and 4 and terminal
2 and 3 were wired together. The 115v schematic shows removing the 2 to
3 jumper and wiring a pitail on terminal 1 and also on terminal 4.
There ar no wires on the 2 and 3 terminal in 115v operation.
Anyone have any ideas what may be wrong with this other than the low
voltage on the transformer???
The motor starter (coil/contactor) is a Furnas D2936-31
Thanks, Steve
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From your description I'd guess that you need to do more than remove the terminal 2 to 3 jumper, most likely connecting 3 to 1, and 2 to 4. Take a look at the wiring diagram again and see if that makes sense. The concept with dual voltage transformers and motors is to provide two sets of coils, each designed for the lower voltage. Wiring them in parallel gives the low voltage connection, while wiring in series gives the high voltage connection. I'm not familiar with the model number you give, but your description of the coil wiring sounds like you're only half way to wiring it for low voltage.
Hope this helps Paul
Reply to
Paul Batozech

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