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Need help rewiring unisaw for 115v

858 Views 7 Replies 4 Participants Last post by  spaltedlvr
Hey folks, been a member for a while, but this is the first time I've needed help, so here we go… (I tried searching online, here, and owwm)

Couple years ago I picked up an older unisaw, it came with a 220 volt only motor, which was fine at the time because I had 220 in my garage. Had it wired up to the starter and the switch with no issues.

Fast forward to today, I only have 115 in my garage, I've already sourced a Rockwell unisaw motor that's dual voltage, I've already got the motor wired for 115 and it works properly, I just need a little help making sure I get the wires switched over correctly inside the starter box and to see if there's any changes that need to be made to the switch itself.

On the Furnas terminal block, I've already moved the voltage wire from h3 to h5 for my corresponding voltage that will be coming into the box. As for the wiring going up to the switch, it's currently a four wire setup, do I need to make any changes to that? Or does that stay the same?

Basically I think I just need to make sure I get the wires connected correctly to the t2, l1 and l2 terminals. The wire coming out of the motor is a three wire setup, black white and green. The wire coming from the power source, would be black white and green as well. I know that I'm going to have an extra wire terminal left over from the 220 setup that I won't need, I just want to make sure I don't hook it up to the wrong terminal.

Hopefully this makes sense, there's a couple pictures of my pre-220 setup, and now with that lead wire on the 115 volt terminal.

Many thanks in advance, if you need more photos or information, let me know and I'll be happy to provide.

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Check the wiring diagram on the inside cover of the starter. Generallly you just need to change the control transformer input voltage (which you have done) and install the proper sized heater for overload protection if applicable. Can you post a picture of the information sheet on the inside cover?

Your control station wiring is a standard three wire setup and should be fine.

I know that I'm going to have an extra wire terminal left over from the 220 setup that I won't need,
Not sure what you mean by that statement… a 240v motor has 3 wires (2 hot + ground), and a 120v motor has 3 wires (2 hot + ground). Where is this extra wire coming from?

...a 240v motor has 3 wires (2 hot + ground), and a 120v motor has 3 wires (2 hot + ground).
- MrUnix
Grr.. let me correct myself before everyone piles on ;) 120v motor has 3 wires, but it's hot/neutral + ground. It is an insignicant difference though, not like going from 3 phase to single phase where you actually do have an extra wire. I'm just getting over what my doctor suspects may be Lyme disease, so my brain is a bit fuzzy - Sorry.

So, I'm kinda an idiot (my words, not yours). I'm honestly not sure what I was thinking, other than that I haven't had the saw in my garage for a long time and I had a brain fart apparently.

Got it all wired up just fine, starter box and all, purrs like a kitten!

Thanks for your responses and help!

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Nice looking rig you have there, glad it all worked out.
Thank you, the way this thing runs is so ridiculously smooth. Now hopefully I'll find some reason to make saw dust!
I was absolutely thrilled when I found a Uni for sale on Craigs List about 7-8 years ago. It was 220. Like you all I had in the garage was 110. I made it easy on myself and simply wired up a 220 receptacle for the Uni…. never looked back (o:
If it was my house (it's a rental), I would. There wasn't even power in the garage when I first moved in, I had to have the owner approve having power run out there, and they only did two 110 lines.

It's okay, I'm set now, and if I ever do have a 220 garage in the future, all I have to do is swap a few wires around.
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