87hz drift with FR-E700

[jydepower 1]

Hallo. Im currently in a project, where some motors have to run 87hz drift to obtain full momentum, above the normal 50hz After searching a on the subject. I found that: The motor should be 230/400V and mounted in delta. The inverter should be set to 400V. At the moment the inverters are set to 230V because at 400V they tripped. But it sounds like they are struggling a lot. As this is very new to me. Id like to hear some advice on this if anyone have had experience with it.

[djtron 0]

Hi jydepower, if the motor is connected in delta, you do not have to supply 400V - output of the inverter should be 230V. Properly the inverter is to small. You have to consider the higher current. By pushing the SET button you can see PV of the current of the inverter. Check this out. Post the details of the motor type plate (best would be a picture) as well the size of the inverter. How is the cooling of the motor realized? Selfcooling?

[jydepower 1]

Ive got most of my info on the subject from a siemens manual The manual states as i wrote in first post. Take a 230/400v motor and mount it in delta with a 400v drive. From what i learned in school, that would burn the motor, and should be mounted as star. But when consulting a siemens dude. He explained me that with higher frequency, the overall impedance would increase in the motor. And that's why it would be possible to run 400v delta instead of 230v delta. The picture from the manual below, shows pretty well how the inverter output 400v at 87hz and 230v at 50hz. So something might make sense. Inverter type: FR-F740-0380-EC I lost my picture of the motor nameplate but found the data on the suppliers homepage: LSMV 132 MU 230vD/400vY 4pole 9KW 1465rpm cos phi 0,80 58,7Nm 18,2A Edited 25 Apr 2013 by jydepower

[djtron 0]

I guess you have to set the parameter of the motor voltage to 230V inside the inverter. At 87Hz it will result in 400V. You must make sure, that it is allowed to connect the motor coils in delta to 400V as well. Consider also that the motor power increases (theoretically) from 9 to more than 15kW! Cooling might be an issue.