Electrical – Running a 15HP Motor with a 30 kW VFD


We are going be buying a 15 HP motor, and using a VFD we have, currently not doing anything. While I'm told that typically, you buy a VFD for the Motor (i.e. 15 HP Motor + 15 HP VFD), we couldn't let the Mitsubishi VFD continue to collect dust.

That being said, could a 15 HP power motor be used with a 30 kW VFD (Mitsubishi FR-F740-00620-EC) without harming either unit?

Search on Google and Stack Exchange regarding running a low power on a high power VFD has yielded no results, so here I am asking.

While I can't imagine it being an issue (my thoughts are VFD is just a power supply deal), we figured it wouldn't hurt to be safe and check.

Best Answer

Your motor is 15 HP x 750 W/HP = 11.25 kW.

The FR-F740 should handle that OK but you need to set the motor type and power.

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Figure 1. Page 153 of the FR user manual.

Start around page 153 of the manual and set up appropriately.