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Forum topic by 716 posted 12-12-2015 10:36 PM 952 views 0 times favorited 20 replies Add to Favorites Watch
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716

502 posts in 381 days


12-12-2015 10:36 PM

I have 2 (two) smallish air condition units in my house. They are installed just outside the shop. I turn them on for approximately 2 weeks somewhere in August. Rest of the year they stay idle.
I wander if I break any building code if I install a parallel outlet to one of the AC circuits to power a 3HP table saw. Does anyone do that ?

-- It's nice!


20 replies so far

View TinWhiskers's profile

TinWhiskers

179 posts in 416 days


#1 posted 12-12-2015 10:45 PM

Somewhere down the road it sounds like trouble. Not for you. But the next person who owns the property. Or the next…
Not exactly sure what a parallel circuit is, but sounds like two AC units and a power saw on one circuit. I’m sure people do that. Is it that hard to run another circuit?

View dhazelton's profile

dhazelton

2325 posts in 1761 days


#2 posted 12-12-2015 10:48 PM

Local electrical code dictates that. But lot’s of folks run a welder off an extension from their electric dryers. No reason you can’t do what you want. Worse case scenario is you trip the breaker constantly. As long as you keep the wire sized to the draw and circuit breaker you should be fine.

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716

502 posts in 381 days


#3 posted 12-13-2015 12:59 AM

Apparently it is not allowed. Even the garage opener circuit should not be used for anything else.

-- It's nice!

View David Taylor's profile

David Taylor

326 posts in 551 days


#4 posted 12-13-2015 04:19 AM

Yup, you’d be breaking NEC 422, which governs circuits for HVAC. Can’t put anything else on them. Legally.

Morally, it’s your house.

-- Learn Relentlessly

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TinWhiskers

179 posts in 416 days


#5 posted 12-13-2015 10:13 AM

Morally…one should stick to code.

View WoodNSawdust's profile

WoodNSawdust

1417 posts in 641 days


#6 posted 12-13-2015 12:36 PM

Local codes may vary but the standard for 240V (220V) is one outlet per breaker. I assume that there is a logical reason for this but I have not figured out the reason.

In reality there is no reason you can’t wire two (or more) outlets to the same 240V breaker. How many devices you can have running at the same time will depend on the total current draw. The problem is whey you go to sell your house if you have to have an inspection they may catch it and require you to hire an electrician to fix it.

Also you need to consider the gauge of the wire that currently runs from the breaker box to the outlet you want to splice into. It may not be heavy enough to handle the current draw of the saw by itself. Check the combined amperage draw off all devices and then round up to the next gauge.

Also, if you had a fire and the wiring was not up to code you may have a problem with your insurance company.

Is the AC electrical outlet close enough to the table saw that you could use a long cord on the TS? Or build a heavy gauge extension code. An extension cord is probably not code but you could always store it somewhere out of site when not in use. Again you need to check the combined wire gauge to make sure you can pull sufficient amperage (power) over the length of the wire from the TS back to the breaker.

-- "I love it when a plan comes together" John "Hannibal" Smith

View rwe2156's profile

rwe2156

2194 posts in 945 days


#7 posted 12-13-2015 12:37 PM

TinWhiskers: Had to laugh about electric code and morality. So if he disconnected it before he sold the house would he be forgiven and if so, by whom?

716: Its a dedicated circuit, but if the AC is not running …....

....just don’t ask an electrician or those in the know to approve of it.

;-)

;-)

What I want to know is where do you get off only running your AC for a couple weeks?

Can I rent a room?

-- Everything is a prototype thats why its one of a kind!!

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dhazelton

2325 posts in 1761 days


#8 posted 12-13-2015 01:46 PM

To make it a little bit copacetic you could extend the feeder (underground in a conduit) from one AC to your garage, install a transfer switch in there and run a loop back to power the AC unit. You’d have to make sure anyone servicing the compressor knows about it.

http://www.northerntool.com/shop/tools/product_200653609_200653609?cm_mmc=Google-pla&utm_source=Google_PLA&utm_medium=Generators%20%3E%20Generator%20Accessories&utm_campaign=Generac&utm_content=49950&ci_src=17588969&ci_sku=49950&gclid=COWw7on82MkCFQotHwodX30DYw

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716

502 posts in 381 days


#9 posted 12-13-2015 06:37 PM

Also you need to consider the gauge of the wire that currently runs from the breaker box to the outlet you want to splice into. It may not be heavy enough to handle the current draw of the saw by itself. Check the combined amperage draw off all devices and then round up to the next gauge.

- WoodNSawdust


Not quite right. The wiring matches the breaker (if installed properly) so the breaker will not let you run more load than the wire can handle.

Regardless. I am trying to be a law abiding citizen and am not going to go against the code.

-- It's nice!

View Kazooman's profile (online now)

Kazooman

626 posts in 1416 days


#10 posted 12-13-2015 07:11 PM

Just curious. Does the code require the AC to be hard.wired all the way back to the breaker or can it have a plug? If the latter scenario is acceptable, you could run one outlet off the breaker and either plug in your AC or the machinery.

Those in the know… Would this be OK?

View daddywoofdawg's profile

daddywoofdawg

1010 posts in 1039 days


#11 posted 12-13-2015 07:32 PM

Is it a plug -in ac? then I see no reason you can un-plug the ac and plug in your saw.if both ac’s and your saw are on one circuit then you’ll pop a breaker anytime they all run at the same time.

View TinWhiskers's profile

TinWhiskers

179 posts in 416 days


#12 posted 12-13-2015 10:55 PM


TinWhiskers: Had to laugh about electric code and morality. So if he disconnected it before he sold the house would he be forgiven and if so, by whom?

- rwe2156

I was helping a friend once…he commented the code does not apply to him. I walked away from that job immediately. I walk away from this discussion.

View AlaskaGuy's profile

AlaskaGuy

2406 posts in 1773 days


#13 posted 12-13-2015 11:28 PM



Is it a plug -in ac? then I see no reason you can un-plug the ac and plug in your saw.if both ac s and your saw are on one circuit then you ll pop a breaker anytime they all run at the same time.

- daddywoofdawg

+1

-- Alaskan's for Global warming!

View MrUnix's profile

MrUnix

4226 posts in 1663 days


#14 posted 12-13-2015 11:35 PM

I am guessing that you have (or should have) a service disconnect upstream of the AC… how about putting a transfer switch rated for the circuit after that, so you could switch between the A/C and the saw. Not sure if that would meet code, but it would prevent you from having multiple devices on the circuit at the same time.

(Just an example of one I found at Home Depot)

Cheers,
Brad

-- Brad in FL - To be old and wise, you must first be young and stupid

View TopamaxSurvivor's profile

TopamaxSurvivor

17671 posts in 3140 days


#15 posted 12-14-2015 07:58 AM



I am gu
essing that you have (or should have) a service disconnect upstream of the AC… how about putting a transfer switch rated for the circuit after that, so you could switch between the A/C and the saw. Not sure if that would meet code, but it would prevent you from having multiple devices on the circuit at the same time.

(Just an example of one I found at Home Depot)

Cheers,
Brad

- MrUnix


Transfer switches should be legal on most circuits. Some inspectors may not like it, YMMV.

The determining factor for multiple outlets on most circuits will be any intended load. If it is more than half the ampacity of the circuit, then a dedicated circuit with a single outlet is probably required. Again YMMV. I doubt if most inspectors would require a dedicated circuit for a table saw or dust collector in a residential garage, but if it is a decdecicated shop, that could easily change his interpenetration of your requirements.

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

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