I want to run a single phase motor with a single phase VFD.

I don't believe that the motor is rated to run with a VFD. To compensate for the issue I would like to use a sine wave filter. Unfortunately finding a single phase sine wave filter has been problematic.

I'm wondering if using a 3 phase sine wave filter and only using 2 phases is feasible?

enter image description here

Additional information:

Link to proposed VFD.

I'm between a rock and a hard place. I have a piece of equipment that was moved from the UK to the US. The equipment itself is north of 500k. It has one small 130W 230V 50Hz motor. The manufacturer of a small subsystem does not offer a US version of the motor. I'm trying to retrofit something to get it working.

Here is a picture of the motor. enter image description here

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    \$\begingroup\$ No. Single phase motors shouldn't be runed with VFD. Sinewave filter either has nothing to do with threephase or monophase AC motor. You have missed a lot. \$\endgroup\$ – Marko Buršič Feb 1 '19 at 14:01
  • \$\begingroup\$ I have never seen a single-phase VFD. Can you post a link to the datasheet for the unit you are considering? \$\endgroup\$ – Transistor Feb 1 '19 at 14:04
  • \$\begingroup\$ @Transistor ato.com/1-2hp-vfd-single-phase-input-output Here it is. \$\endgroup\$ – vini_i Feb 1 '19 at 14:07
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    \$\begingroup\$ @MarkoBuršič What is preventing the use of a single phase VFD with a single phase motor? A sine filter is used to smoothout the switching frequency of a VFD so that the motor only sees the intended fundumental frequency. I'm not sure i've missed anything at all. \$\endgroup\$ – vini_i Feb 1 '19 at 14:14
  • \$\begingroup\$ If they claim it works, then give try. But sinewave filter is a totally different story. They are used for very long motor cables, they have to be well choosen / designed for specific application. They are problematic, feroresonce, high voltage peaks, ..etc. Don't use the filter. \$\endgroup\$ – Marko Buršič Feb 1 '19 at 14:14

For operation on VFD, a single-phase motor must not be the capacitor-start type. It must be the permanent split capacitor (PSC) or the shaded-pole type. The load must have low torque at low speed as with a fan or centrifugal pump. Adding a sine filter will not alter those restrictions. A sine filter would prevent damage from insulation stress due to PWM switching transient ringing. Using the three-phase filter will probably not harm anything and may be of some benefit. If the VFD is near the motor, a filter is probably not needed.

There is a manufacturer of VFDs for single-phase motors that claims to have features to allow more latitude with motor design and load type.

Re Comments

You may have alternatives other than a VFD. A frequency changer may be a better alternative. The motor may operate reliably at 230 V, 60 Hz, but the speed would increase by 20%. If the load is a fan or centrifugal pump, the load torque would increase by 44% because of the increased speed and almost certainly overload the motor.

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  • \$\begingroup\$ The motor has a run capacitor not start capacitor. Not sure as to the kind of pump that it has. \$\endgroup\$ – vini_i Feb 1 '19 at 15:54
  • \$\begingroup\$ A picture may help, but you may just bee to take a chance on whatever choice you make. I would be good to be able to monitor motor current and temperature. Failure to start would be evident right away. A seriously overheated motor would probably be hotter than you would want to touch for long. A slightly overheated motor might fail in a few years or so as compared to 10 years or more for a motor at normal temperature. A VFD or electronic frequency changer should shut itself down it it has a problem. \$\endgroup\$ – Charles Cowie Feb 1 '19 at 17:33

The motor on the picture is a small AC induction motor. Instead of experimenting with strange technology, no name VFDs I would reccomend you to change the motor with a three phase motor with similar specifications.

You will hardly find such motor 60 size, but there are plenty of 63 size or 56 size. For example a Lenze MDERAXX056-21V1C three phase has 140W at 60Hz/460V or 120W at 50Hz/400V. All you need is to put a spacer of 4mm below the motor to reach 60mm shaft height. Then you might need a differnt coupling to properly attach the load.

With 63 size motor, you have to somehow lower the motor position with respect of shaft position.

IMO that's the best way if you want the machine work 100%.

You should also take some photo to see how the motor is fixed and how it is coupled with load.

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