# Servo motor, usable or not?



## Srdjan79 (Oct 19, 2017)

Most honored diyers, 

I have in my possesion a Siemens 1ph7107-2hd02-0bb3 servo motor. Originally I intended to use it for controller testing, however recently I had a thought it could possibly be used for ev (sort of) conversion.

From the nameplate:
- 6.25 kW at 319 V/35.3 Hz, wye connection
- S1 duty cycle
- 1000 1/min (I guess 6 poles), max 9000 1/min 
- 71 kg

My battery pack/controller setup is ~500V, so if this motor could be recconected to delta that would give it about twice the nominal power and speed, maintaining the v/f ratio: 
- 319 / √3 * √2 ~ 260 V peek in delta
- 500 / 260 * 6.25 ~ 12 kW
- 500 / 260 * 1000 ~ 1900 1/min

Below is the view of the terminal box, where only three (U1,V1,W1) terminals are present.
Terminal_box

I would appreciate if anyone would comment on the choice of this motor for ev conversion. Some extra features it has is built in separate blower and pulse encoder.

Also, if someone has experience with similar motors, would it be possible to reconfigure this motor to delta relatively easy?

Any help would be appreciated


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## jhuebner (Apr 30, 2010)

I have a motor that was internally connected in wye. I had to open it up, remove the heat shrink, unsolder the copper connections, then I connected in delta. While at it I found that each phase consisted of 4 coils all wired in series (basically 4S). I changed that to 2P2S. But it was a lot of work to find out which coil belongs to which phase. If you have the opportunity to run this motor at 4000rpm at full torque you'd get quite respectable 25kW, I would even say continuous.

I would try it


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