Any 5hp 3 phase Sawstop users out there with RPC's

[Keith Hankins]

Ok I'm getting ready to order my Sawstop and was speaking to them and have a question for sawstop users 3 phase. Anybody out there using an American Rotary digital phase converter? Sawstop indicated that some RPC's if the sine wave is not perfect can cause an error and fire the brake cartridge. I spoke with AR, and have tested mine, and across all three legs they are within 3% of each other which is great. Sawstop indicated that if there is an issue putting the generated leg in the center lug (or red lug) would resolve the issue since that leg is not used by the braking system.

Any body using three phase in this configuration?

[Rich Riddle]

You are confusing a sine wave and the voltage differences. Voltage on a sine wave are shown in the extreme up/down positions. The complete cycle is shown on the left to right. On a three-phase machine each sine wave is 120 degrees "out of sync" from the other two phases. On a split-phase, the two phases from the power company are 180 degrees apart, not 120 degrees apart. The "slave" motor in a rotary phase converter generates the third phase, but they are never exactly 120 degrees apart like from a real 3-phase input. Look at the images below to see what I mean. In the example, I pulled up a picture of one that is 90 degrees apart. It's easier to look at than explain.

Three Phase.jpgSplit.jpg
In order to get a perfect 120 degree sine wave, you will have to use a variable frequency drive. At the 5 HP range, they aren't cheap.

[jack forsberg]

digital phase convertor don't have a wild leg like the rotary phase converter (they do not generate the 3 leg (wild) through a 3 phase motor/ilider ) that's why there 10 time the cost of a RPC. they are just like a VFD with out the frequency control . that is about the cleanest 3 phase power you will get from single phase input there is though a VFD will do the same thing for far less $$$$$$$( about 350). The saw don't come single phase?

[Erik Loza]

Good question.... I would just get the 1-phase model. Keep life simple.

Erik Loza
Minimax USA

[Keith Hankins]

Thanks for the reply and the education. I managed to get to an engineer at AR and my model is a digital converter and will be ok. I did some reading based on your reply and learned a lot. Thanks.

[Mike Heidrick]

American Rotary's TRUE digital drives are called Phase Perfect and they are multiple thousands of dollars and not hundreds. There is no spinning motor of any kind in the Digital Phase Perfect units Jack is talking about. Night and day different machines.

I know some of you boys (Gary, Brian, Joe??) are running the bad boy Phase Perfects! Many of those boys are Felder/MM/Euro slider saw owners not SS