Failed converter attempt

[Dhal22]

My electrician (with his lack of experience in converting power) recommended a phase converter based upon equipment costs. It did not work, something about the 3rd leg, so I ordered a rotary converter. We will see.......

Phase converter photo then photo of rotary converter.

 

[mksj]

There are numerous reports/feedback on the DPS. it is just a static converter. They even say in the directions you cannot measure the 3rd leg unless connected to a running motor. Someone under the Amazon feedback took one apart, basically some capacitors and I assume switching is digital as opposed to analogue (relay) for the start capacitor. Nothing else that would indicate it was a VFD or similar device that would generate 3 phase actively. The posting/picture was subsequently removed, so bespeaks about the influence of companies and big business. The DPS was also appears to be short lived with difficult loads like compressors and so forth based on feedback. If you tried a DPS and it was not directly connected to your motor, then you need to hookup transformers and machine controls to the non-generated legs, as there will be no voltage on the wild/generated leg to operate anything.

 

[rabler]

The rotary phase converters work pretty well. Just beware that you can't use phase to neutral voltage as an indication of anything meaningful, you have to measure phase to phase.

 

[matthewsx]

I've owned two North American static phase converters. Great value for the money IMHO and you can upgrade to rotary if you have, or can get a suitable 3 phase motor.

Love my VFD's on the lathes where I don't have any significant control wiring but on my mill with all it's switching I just can't see converting it to one.

John

 

[addertooth]

Hearing all the conversations which circle around on this topic makes me glad I have brushless 3 phase motors on my lathe and mill, which manages the required variable frequency phased signals for the brushless motors. The downside is, those motors are hard to find in meaningful Horsepower figures. A BIG one would be 1.5 H.P. For their given HP they do offer very good torque and speed control.

They are commonly found on variable speed lathes and mills that run on 120 VAC.

 

[AGCB97]

Love my VFD's on the lathes where I don't have any significant control wiring but on my mill with all it's switching I just can't see converting it to one.

For as easy, cheap and having so much control over stuff, as I have found, I have no desire or need to monkey with converters, either rotary or other. Although for a learning experience, I did build a rotary and sold it to my BIL.
I also love them!
Aaron

 

[MrWhoopee]

I am using, and am quite satisfied with, a static phase converter, which is what the DPS appears to be. (Mine was even cheaper) On startup, the third leg is provided with a short burst of power from the capacitors which starts the motor spinning. If the machine has powered controls (relays, etc), they must be wired to one of the two hot legs, not the third (wild) leg. Your problem with the DPS could simply be that it is connected to your machine incorrectly. A picture of the machine controls might help.

 

[JimDawson]

The downside is, those motors are hard to find in meaningful Horsepower figures.

Not at all hard to find, but not cheap. They are available up to around 700HP that I know of. I recently replace the spindle motor on my lathe with a 10HP (7.5kW) unit.

 

[addertooth]

JimDawson,
That is some impressive power.

 

[Dhal22]

I'll send a link to this thread to the electrician. Thx guys.