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View Full Version : 3ph. 3hp. Tablesaw. on 1ph. to 3ph. converter



Dick Brown
07-18-2018, 11:06 PM
Question for the electrical gurus,
I did a bit of trading while back and ended up with a 3ph. 3h.p. cabinet saw. I only have 1ph. power so debating to get a different motor or a phase converter. On odds of 1000 to 1, last weekend I stopped by a yard sale and there, among some other electrical stuff was a 4 to 8 h.p. 1ph. to 3ph. converter. Price was right even if it wouldn't work so I bought it. Called the company to ask if it would work for my 3hp. saw and the guy I talked to was not very helpful. Went to the shop, wired it up, hit the switch and it ran like a top. My question is the same as I asked of the phase converter co. man. Will it be o.k to run a 3hp. motor on a 4 to 8 hp. converter or am I flirting with trouble? I realize I will only have about a 2h.p. saw with the converter but that is not a problem.
Thanks,
Dick

fRED mCnEILL
07-19-2018, 12:11 AM
I bought a 3 hp 3ph saw for my son and also a static phase converter. (up to 5HP I think) works fine.

Matt Mattingley
07-19-2018, 12:29 AM
- A static phase converter fakes out, and provides power to the third leg for about four seconds. After that, The motor is running on less than 2/3 power. This is usually the cheapest solution.
- finding a perfect used replacement single phase motor and doing some re-wiring is the second best cheapest solution.
- purchasing a single phase to three phase VFD and doing some re-wiring is the third cheapest solution.
- purchasing or building a RPC is the fourth cheapest solution.
- Purchasing phase perfect is the most expensive solution.

To answer your question, there is no problem so long as your eyes and ears and mind, on start up are fully paying attention. The converter you have is a static converter and technically could be giving too much juice to the third leg during it start up. Depending on how you have it wired and if it goes into lock rotor for too long, could fry the motor windings, and hopefully throw your breaker.