# Electric run and wire size



## mike85215 (Oct 16, 2009)

Okay I know that it is a little late to be asking these questions but here goes….
Last week at work I ran a new electric line for an instant water heater for the kitchen area in the sales office. I ended up running a three wire loose line of 12 gauge with a 20 amp breaker and a 15 amp outlet. The run was a little less than 60 feet. The heater calls for a 20 amp circuit and it draws 2400 volts.
My question is what do I need to go back and fix….if anything.??
Thanks for your help.
Mike


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## TopamaxSurvivor (May 2, 2008)

You need a 20 amp outlet on a dedicated 20 amp circuit.


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## mike85215 (Oct 16, 2009)

Thanks Topomax…I was hoping that you would answer. I did open a new 20amp circuit that is dedicated for only the heater. I wasn't sure about the length of run and if it would make a difference on the gauge of wire. So I need to change the outlet from 15 to 20 amps ? Anything else that I missed?


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## TopamaxSurvivor (May 2, 2008)

Normal building wire sizes are good for 100 feet or so. Not much info there. No way to tell how many code violations are in your methods. Have it inspected to be safe.


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## mike85215 (Oct 16, 2009)

Thanks for helping. I will get it inspected next week.


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## WoodSparky (Nov 27, 2009)

I disagree. You can put a 15amp receptacle on a 20amp circuit.


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## TopamaxSurvivor (May 2, 2008)

Not if it is a dedicated circuit for a specific piece of equipment. In most cases you can only use a a single outlet, not a duplex.


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## Gregn (Mar 26, 2010)

If it were me I'd run 10 gauge wire for 240 volt instead of 12 gauge wire. But thats just me.


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## TopamaxSurvivor (May 2, 2008)

Lower the voltage, the higher the voltage drop. You wouild be better off running #10 for 120 than 240.


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## Pete_Jud (Feb 15, 2008)

I assume 2400 watts, not volts. That is 20 amps at 120 volts, or 10 amps at 240 volts. 12 g at 60 ft would be ok, 10 better. But if you use a toaster, microwave or coffee maker on that 15 amp 120 outlet, It might be a little much for the 20 amp breaker and 12 g. I would make the run 10 g, and run the wire as 240, put a small sub panel in the kitchen. Put a 120 V 20 amp circuit breaker one leg on the circuit to the water heater, and put 15 A or 20 A on the other leg for the 15 A duplex outlet. Put a 20 amp 240 breaker for the 12 g going to the kitchen. 60 feet of 10/4 is not to pricey for the safety and utility. An office kitchen can see a lot of loads, my shop finishing room/kitchen has a small fridge, coffee maker, and microwave, and often all three are running at the same time.

good luck


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## TopamaxSurvivor (May 2, 2008)

That is all irrelevant. Any device using 50% or more of the circuit capacity requires a dedicated circuit and a single outlet if cord connected.


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## crank49 (Apr 7, 2010)

Topo is correct. You only need to change the outlet in terms of electrical code.. assuming everything is installed properly. The wire size and breaker will be ok for a 2400 watt load; but fully loaded at 120 volts. A water heater is a resistive load, so even though you are going to get a little voltage drop on the long run it will not really hurt anything; the heater will just not heat quite as fast as it would on a 10ga circuit.


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## mike85215 (Oct 16, 2009)

I did run a duplex outlet, however it is located underneath in a cabinet and will not be used for anything other than the water heater. Yes it is my mistake it is watts and not voltage. The question now is does the 15 amp outlet need to be changed to a 20 amp ? Or knowing that it will not be used for anything else will the 15 amp be okay?


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## davidpettinger (Aug 21, 2009)

Topo is right. here where I live, a microwave must be plugged into a single 20 amp outlet. So must a dishwashe and a sink mounted water heater.


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## TopamaxSurvivor (May 2, 2008)

A device that uses 50% or more of the circuit's capacity requires a dedicated circuit and a single outlet, not a duplex. They started requiring single outlets for washing machines, disposals, ect a code change or 2 ago. Therefore, sounds like you need a single 20 amp outlet on your circuit since it says a 20 amp circuit on the device and it draws 2400 watts.


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## birdguy (Jun 10, 2010)

Ok are the wires exposed? If so u should use conduit I prefer metal why 3 indivual 12wires not romex or sompting


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## Nomad62 (Apr 20, 2010)

I am a fan of over-doing electricity circuits. Wires too big, circuits well protected, fires avoided. The reason for big wire is that a small wire becomes a fuse; it will heat up and burn if the load is too high. The circuit breaker needs to be able to protect the circuit, if it's right at the break point (2400 watts is 120 volts at 20 amps) it may trip over and over at start-up and wear out. 2400 watts… I would look to see if it is 240 volt capable and do that if possible. If not, I would definately use 10 gauge wire; it may not be "necessary", but it's a cheap insurance policy.


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## Jim Jakosh (Nov 24, 2009)

If you are protected with a 20Amp breaker in the box, 12 ga wire is okay. However, with that wire size the extremities should also be protected. I would put in a 20 amp outlet so you have the heavier contacts for that 20 amp load plugged into it. If it is hidden, there is a good chance nothing else will ever be plugged into it.


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## BigJimAK (May 22, 2009)

If it really draws 2,400 watts (20A resistive) and you want to do it legitimately, you're missing one thing: the National Electric Code limits you to a load that's 80% of the breaker size. Going to a 30A breaker would require #10 wire.

Will it work as it is? The answer is a definite maybe. Being borderline you may find that it trips the breaker only after a large draw of hot water (or when it first fills, but after a while), where the heater must run for an extended time to catch up.

The final thing is that, should you decide to sell your house some time in the future and an inspector finds it, reputable financing companies would require you to change it before the buyer can get financing.


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## TopamaxSurvivor (May 2, 2008)

When the manufatcurer's label says 20 amp circuit required, that is what is required. End of discussion.


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