Hooking up a variable frequency drive

by Zachary Russell Heineman   Last Updated September 11, 2019 15:25 PM

I have a 3-phase blower motor that I am looking to control from a Danfoss VLT 2800 that I purchased on eBay.

I have in the shop a receptacle that looks like this: receptacle image

If I put a meter from neutral (horizontal middle) to either hot side (the verticals) I get 120v. Across the hots I get 240v. The table suggests that for single phase I should only be connecting two wires, including a neutral. But with the neutral I have I only get the 120v. Should I just be connecting the two hots?

For reference, our building has high-leg delta service.



Answers 2


European phase voltage is 230 Vrms (line voltage is therefore 400 Vrms). Here in the US we have to connect the two "hots" to get a comparable voltage, that is 240 Vrms.

You are fine connecting one split-phase "hot" to L1 and the other one to L2. Make sure to connect the ground as well. The split-phase neutral should be left disconnected.

enter image description here

SunnyBoyNY
SunnyBoyNY
January 09, 2016 21:26 PM

Yes, two hots. And most important is the ground, leave the neutral unconnected. By the way what's "high-leg delta service", and the table you are refering at is not visible. Also you have to check the motor connection star/delta for correct voltage.

Marko Buršič
Marko Buršič
January 09, 2016 22:04 PM

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