Need Advice from an Electrical Genius

[gsmittle]

I have a vintage Jet table saw (around 1992; how can that be vintage already?) with a three-phase motor. I couldn't find an affordable single-phase motor to replace it with, so I opted for a phase converter. So here's my question: The phase converter's mounted to the side of the saw, but what do I do with the ground wire? Do I attach them both (single-phase and three-phase) to the saw, do I tie the grounds together, or what?

Here's a pic for reference. I haven't wired the three-phase side yet.

[LCHIEN]

I'm more attuned to electronics but I know the electrical a bit.

Your incoming single phase 240 power should have three wires, L1, L2 and ground. So the ground wire or ground terminal of the converter should be tied to the incoming power ground. Your saw chassis should also be grounded to this ground. DOes the convertor even have a ground wire/terminal? If not the the ground should go to your saw. In a normal home the ground should be 120 V from each of L1 and L2 providing the reference.

The three phase side I imagine is also referenced to ground in some way internal to the converter. It sort of doesn't matter if its delta or Wye.

The picture is not very informative, I can't even see where the green wire on the edge of the picture goes. Is that from your power cable?
Here's the instruction manual. fb7b9118-76d2-5fc6-8d81-f200e4605ee2.pdf

It does say the device should not be used with motors less than 4 HP, for some reason. I presume you are aware of that.

If you are unsure they have a support service at www.vevor.com/support - ask them.

[gsmittle]

Thank you Loring. Duh, I even RTFM'd before I started and forgot all about the tach support. The green wire is the ground from the power cable and is attached to the saw. The motor is a 5 hp, so I should be good there. I'll try support and see what they say.

Thanks again!

[d_meister]

Looks to me that the converter is for UK/EU power supply, going by the labeling and power-in configuration. The certifications should be UL for US service. The others are all UK and European. UK CA is United Kingdom Conformity Assessed As Loring notes, the box should have L1, L2, ground, and maybe neutral for a US system. That installation could be dangerous with the exposed wire connections.

[LCHIEN]

Yeah, I noticed the exposed wire connections. It really needs to be protected from accidental contact... enclosed.
as D Meister says looks like for European markets.

[dbhost]

I have nothing of value to contribute to this conversation as I am anything but an electrical expert, However I am a bit stunned that you couldn't find a suitable single phase motor for less than a phase converter. Maybe I was misinformed but I thought phase converters are kind of spendy...

[LCHIEN]

electronic phase converters are relatively cheap these days. Big iron motors are not, Plus, you can speed control them and reverse them easily with a VFD, a fancy phase converter.

[dbhost]

LCHIEN yeah, didn't know that. Was always under the impression that the phase converters were a huge expense. I guess like 5HP + motors can be steep though...

[gsmittle]

Update: I got the converter working (turns out I had some gunk in the switch) and turned on the saw (had a blade mounted but below the tabletop). There was a horrible clanking and grinding noise, and when I turned the saw off, the blade kept spinning for quite a while. I noticed the arbor nut was loose and realized the motor was running in reverse. Swapped two wires and it runs fine

I also covered the exposed terminals with plenty of liquid tape and a layer of tape over that.

Still setting up the saw. I’ll update when I finish.