110 to 220 v step up tranformer for a table saw: crazy or safe?

[plinmaine]

I'm the proud new owner of a 1994 unisaw.  I need to get 220volts to the garage and in lieu of hiring an electrician and negotiating with my landlord, I found this:  http://www.220-electronics.com/5000-watt-diamond-series-voltage-converter.html?gclid=CjwKEAjwltC9BRDRvMfD2N66nlISJACq8591dnBR1pTyRN0NhUYnqC6O-Vf-MwTuW4QI3rwrwSLKqxoC_Inw_wcB

Is this a guaranteed trigger of my renters insurance due to housefire?  Is it safe?  Has anyone used this instead of a rewire job?  

Thanks y'all.

 

 

[Chestnut]

You can't change power. If the saw is 3hp at 220 there isn't a circuit that will power that safely in my opinion. Max amps on a 120v is 20 amps which puts the biggest motor right around 2hp no matter how you transform it between the wall and the machine.

Power (watts) = volts x amps

[Woodenskye]

I would speak with your landlord and propose that you will pay for the work using a licensed electrician.  In some ways this could be considered an upgrade that he won't have to pay for.  I would rather do it right and not jeopardize anything.  There should be a way to do, so that even if you have to remove when you leave it would be that hard.

[Gixxerjoe04]

Is your breaker box in the garage?

[drzaius]

Chesnut is right, 2 HP will barely run on a 120V, 20A circuit. And it better be a dedicated receptacle that is close to the panel, of voltage drop will be an issue.

That unit is basically plug & play, it looks like. So installation shouldn't be an issue. And it has enough capacity to run the saw. Starting it may be another matter.

[Tpt life]

1 hour ago, Chestnut said:

You can't change power. If the saw is 3hp at 220 there isn't a circuit that will power that safely in my opinion. Max amps on a 120v is 20 amps which puts the biggest motor right around 2hp no matter how you transform it between the wall and the machine.

Power (watts) = volts x amps

I have routinely used 30 amp single pole for furnaces. 

[Chestnut]

3 minutes ago, C Shaffer said:

I have routinely used 30 amp single pole for furnaces. 

I stand corrected. I guess i never think of 30 amp and 120 because i associate 30 amp with 240. I also thought that a multiple branch circuit had to be 20a or less?

That being said i highly doubt it's a 20A circuit my bet is on 15A.

[Ryan Grondin]

I think what ches was trying to say is Max amps on a 12/2 romex @ 120 vlts is 20 amps.... If it's 10/2  then 30 amps... etc. But keep in mind, you should only be using 80% of your breakers capacity... If you exceed 80% just bump up your wire guage and breaker.  That unit would probably work.. seems gimmicky but it might work.. How far is your electrical panel from where you need the 220 line? You could slapp in a double pole breaker, I'd go with a 30 amp and run #10 guage wire to it... that will be plenty. You might possibly be able to just run it temporarily then pull it out when you move... sleeve it in pvc in your shop if your worried about it being damaged. Just my two cents... or three...

[Pwk5017]

3hp unisaw only needs a 20 amp breaker, so you can use 12awg. I would do it right and propose an electrician to come out and run the line. If you LL pushes back, propose an increase in security deposit to cover the reverse of the electric work. I cant imagine what landlord would fight you on that. First thing is first, go to your panel and open it up. Do you have two extra slots that are free? If yes, proceed to the advice above. This should be an inexpensive thing to do in most parts of the country. I ran all my own lines, but materials would be about $50 for breaker, 50' of 12 romex, and a box with receptacle to match your plug. Should be less than an hour of labor for any electrician worth his salt(more like 15 mins for any electrician worth his salt), so i dont imagine labor to be too high. 

[Tom King]

Do you have an electric dryer, and/or stove?

[Tpt life]

For any of you wiring in garages, stranded in conduit carries different amperage ratings in local codes. I can get a 30 over 12awg in metallic grounded conduit. I think the codings most commonly found are THHN and THWN. Knowing that these motors tend to spike on start up and then run at a lower draw, this can be a decent arrangement. Knowing how garage spaces work, a conduit run might make sense. I would not do this over a long run. For a long run I would use 10awg. By the same process, I think you can run 50 over 10awg in conduit. I would have to dig because it has been awhile, but I don't prefer running shop electric with Romex. 

[Ryan Grondin]

It's still 30 amps for 10 awg THHN. But Counduit would be better..., then you could pull some spares for other things.. future tools.. extra power.. Keg fridge. lol

[Eric Anderson]

Where I am, all garage electrical must be GFCI protected.  This meant, for me, a GFCI breaker in the main panel.  I then ran to a sub-panel in the garage where everything else branched from.  The 60 amp GFCI breaker (Cuttler Hammer) was  $125 by itself. Then 6 gauge stranded wire (~$1.25/ft per wire) in plastic conduit buried from the main panel to the garage sub-panel.  Parts alone were almost $600.    

[Tom Cancelleri]

18 hours ago, C Shaffer said:

For any of you wiring in garages, stranded in conduit carries different amperage ratings in local codes. I can get a 30 over 12awg in metallic grounded conduit. I think the codings most commonly found are THHN and THWN. Knowing that these motors tend to spike on start up and then run at a lower draw, this can be a decent arrangement. Knowing how garage spaces work, a conduit run might make sense. I would not do this over a long run. For a long run I would use 10awg. By the same process, I think you can run 50 over 10awg in conduit. I would have to dig because it has been awhile, but I don't prefer running shop electric with Romex. 

10 Awg THHN is rated for 30 amps max , no matter what. In fact, if it's ran in conduit with any additional branch circuits you need to upgauge your wire to take into consideration the derating of the wire due to multiple circuits in one pipe. There's a chart for it, as well as a maximum number of wires per conduit run. 

 

2 hours ago, Eric Anderson said:

Where I am, all garage electrical must be GFCI protected. 

Such a ridiculous code! I think that was part of the 2011 NEC standard. Needing a GFCI for a garage door opener outlet in the ceiling is among the most absurd things I've seen in the code changes. The 2012 code now calls for a neutral in your switch boxes. 

Another ridiculous code is the tamper proof outlets in the garage. Because I know tons of parents who let their kids run around the garage sticking forks in those outlets. 

[Andy Wright]

On 8/18/2016 at 4:08 PM, Tom King said:

Do you have an electric dryer, and/or stove?

Good point - you can put together a 220V cable to run over to the dryer outlet