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Forum topic by SweetTea posted 11-06-2017 02:30 PM 1302 views 0 times favorited 21 replies Add to Favorites Watch
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SweetTea

242 posts in 492 days


11-06-2017 02:30 PM

I have a quick electrical question that I was hoping to get some opinions on. I have two 220v 20amp lines that I need to make longer due to having to rearrange my shop. They are for my Delta UniSaw and my 3HP Grizzly Shaper. The wire is currently 12/2 each with its own 20 amp double pole breaker. My question is would it damage my equipment or cause any significant voltage loss if I were to splice those lines to make them longer? The situation is that we can’t pull new (longer) wires right now. Might be able to in the future. But for now I will have to splice them. Local code is not an issue, I just want to know if this will cause any issues with my machines?


21 replies so far

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Srini

29 posts in 612 days


#1 posted 11-06-2017 02:41 PM

Did you consider making your own extension cord using portable power cord you get in home centers? This way you can always use the extension cord for other purpose.

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jonah

1441 posts in 3131 days


#2 posted 11-06-2017 03:06 PM

You can use more 12/2 wire to make those runs longer if you need to. You will need to make that connection inside a junction box that is accessible in the future. Be sure to use wire nuts suitable for that size wire.

“Local code is not an issue” is a terrible, horrible, no good, very bad reason to do substandard electrical work.

View rwe2156's profile

rwe2156

2707 posts in 1313 days


#3 posted 11-06-2017 03:19 PM

According to my electrician you won’t get significant voltage loss less than 50’.

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

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Carloz

952 posts in 424 days


#4 posted 11-06-2017 03:48 PM

Splicing is not a problem is done properly. Long line often is.

View GR8HUNTER's profile

GR8HUNTER

2947 posts in 545 days


#5 posted 11-06-2017 04:00 PM

how much longer do you need ?? :<))

-- Tony Reinholds,Pa. REMEMBER TO ALWAYS HAVE FUN

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WhyMe

909 posts in 1393 days


#6 posted 11-06-2017 04:14 PM

At 240V (220V no longer valid) that 3HP shaper can go on the end of a 20A circuit 100’ to 125’ with no problems. The saw should be the same.

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TheFridge

8287 posts in 1318 days


#7 posted 11-06-2017 04:15 PM

It’ll be fine.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

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clin

750 posts in 828 days


#8 posted 11-06-2017 04:18 PM

As mentioned, splicing is okay if done in an accessible junction box. Longer is okay, if ….

I believe code has limits on how long a run can be for a given circuit rating (15 A, 20 A etc) for a given wire size. You can look that up. So there will be some max length for a #12, 20 A run. Some loads will draw MORE current as the voltage goes lower (not everything behaves like a resistor). I assume this is why code is concerned with this.

I’m pretty sure code always applies in the USA. I believe each state enforces the NEC with a few of there own local modifications. But even if you don’t legally need to do it, the code exists to ensure a safe installation. Sure there will always be situations where some code restriction isn’t making it safer. But unless you’re an expert, it’s always best to stick with the code which has been developed by experts over many decades.

I also doubt it is code to extend a circuit with anything other than the same wire size. This would run the risk of fooling someone into thinking the whole circuit was at the larger wire size.

You didn’t mention how much longer you want to make the wires, but here’s an example to give you an idea what will happen.

Assume you add 100 feet. That creates 200 feet, round trip of wire. #12 wire is about 1.7 mOhms per foot.

total added resistance = 1.7 mOhms/ft x 200 ft = 0.34 ohms of resistance.

Volts = ohms amps

For the added voltage drop of 100 feet at the maximum 20 A circuit current.
volts = 0.34 ohms
20 Amps = 6.8 V

This is on a 240 V circuit so represents 2.8% decrease in voltage at maximum current.

Of course, you won’t be operating at max current of 20 A or likely even near it except when a motor starts. So would this matter, I have no idea. Though I doubt it would be noticeable in most cases.

-- Clin

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WhyMe

909 posts in 1393 days


#9 posted 11-06-2017 05:05 PM

There is no set length limit of a circuit in the NEC. Calculated loads and distance set the conductor size and length limit. Two different wire sizes can be used in a circuit but the over current protection must be set to the smallest conductor size in the circuit.

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SweetTea

242 posts in 492 days


#10 posted 11-06-2017 06:11 PM

The lines just need to be 10ft longer. I will use the same wire size, 12/2, and make the splices inside of a junction box. Thanks for the help fellows!

View GR8HUNTER's profile

GR8HUNTER

2947 posts in 545 days


#11 posted 11-06-2017 06:31 PM

that will be no problem then exactly as you said :<))
IS IT DONE YET LOL

-- Tony Reinholds,Pa. REMEMBER TO ALWAYS HAVE FUN

View Fred Hargis's profile

Fred Hargis

4753 posts in 2326 days


#12 posted 11-06-2017 08:08 PM

I m pretty sure code always applies in the USA. I believe each state enforces the NEC with a few of there own local modifications.

- clin

This was a question I had (enforced by states, and which ones) so Google is your friend. What I found was that there are 3 (AZ, MO, MS) states that haven’t adopted the code, and the others have adopted different versions. I know where I’m (my local) at (Ohio) there is no active enforcement unless it’s at the municipal level. In fact, a small village that supplied power to my last house knowingly allowed violations of the code in some structures they serviced. I thought this was kinda interesting, especially since I didn’t think I was subject to the code at all.

-- Our village hasn't lost it's idiot, he was elected to congress.

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SweetTea

242 posts in 492 days


#13 posted 11-07-2017 01:46 PM


I m pretty sure code always applies in the USA. I believe each state enforces the NEC with a few of there own local modifications.

- clin

This was a question I had (enforced by states, and which ones) so Google is your friend. What I found was that there are 3 (AZ, MO, MS) states that haven t adopted the code, and the others have adopted different versions. I know where I m (my local) at (Ohio) there is no active enforcement unless it s at the municipal level. In fact, a small village that supplied power to my last house knowingly allowed violations of the code in some structures they serviced. I thought this was kinda interesting, especially since I didn t think I was subject to the code at all.

- Fred Hargis

LoL, I have had a similar experience with regard to code. I live in a small town in the rural south, and our local electrical inspector is my next door neighbor. In my previous shop, which was a commercial shop, we had to run some new lines for outlets at various machines. I was just starting my business and already had the wire but no conduit. It was a pole barn style shop with open walls. Well I ended up running the wires with no conduit, which is technically against code in a commercial shop in my state. I had my neighbor, the electrical inspector, come look at it, and he said, “looks good to me”.

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rwe2156

2707 posts in 1313 days


#14 posted 11-07-2017 03:20 PM

Off the subject, but I’ve always maintained the insurance companies should be doing the inspections, not the government.

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

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HerbC

1684 posts in 2692 days


#15 posted 11-07-2017 04:23 PM



Off the subject, but I ve always maintained the insurance companies should be doing the inspections, not the government.

- rwe2156


This would be the same insurance company which made me get rid of diving board and slide on swimming pool to avoid cancellation of my homeowner’s insurance? The board and slide had only been in use for thirty-five years. They wouldn’t even let us keep them if we signed a waiver of liability related to pool and equipment.

-- Herb, Florida - Here's why I close most messages with "Be Careful!" http://lumberjocks.com/HerbC/blog/17090

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