110 Wire Guage question

[woodlandfarms]

On a 110 circuit, can a hot leg be bigger than the Nuetral? Can the hot be a 10 guage and the nuetral a 14. I am assuming no as the amperage on a 10 could potentially overwhelm the Nuetral, but I have to ask.

 

[aczlan]

No, in a US 110v circuit there is equal current on the hot and neutral legs so with a 10ga hot and a 14ga neutral you would be limited to 15 amps (depending on the length of the run).

Aaron Z

 

[CliffordK]

Sometimes companies will mess around with the ground wire which may be smaller than other wires, and normally doesn't carry power.

For an ordinary 110V circuit, your power goes through the "HOT" and returns with an equal amount through the "Neutral" (ignoring the AC), so that the two legs MUST be equal.

One can legally wire two 110V circuits through a 3-wire (220V), and split them, although I don't like doing it.
Say you wire up two lights with a split 220V circuit.
Light A on, B off ==> power from A+ to Neutral.
Light B on, A off ==> power from B- to Neutral.
Light A on Light B on ==> Power from A+ to B-, NO POWER THROUGH Neutral. Thus the wire is not undersized.

I got a set of HF magnetic taillights that have a critical problem.
4 wires, Neutral, taillights, right signal, left signal.
Since it is all one phase, 100% of the return power goes through the Neutral wire, and since they are magnetic, they don't ground to the frame.
Anyway, HF undersized their wire, and if you turn on the taillights, and use the signals (worse if you use hazards or brakes), then the neutral just doesn't cut it as it can't deliver 3 times the power as the other wires.

 

[aczlan]

I got a set of HF magnetic taillights that have a critical problem.
4 wires, Neutral, taillights, right signal, left signal.
Since it is all one phase, 100% of the return power goes through the Neutral wire, and since they are magnetic, they don't ground to the frame.
Anyway, HF undersized their wire, and if you turn on the taillights, and use the signals (worse if you use hazards or brakes), then the neutral just doesn't cut it as it can't deliver 3 times the power as the other wires.

LED bulbs will fix that problem (need to get a set for our set of those lights).

Aaron Z

 

[woodlandfarms]

What it is is that I am using a recently run well wire (not the wire into the well, but the wire to the well) which is a 3 (4 wire with ground) but looks to be maybe 12 guage if not 14. This is a mystery to me why the wire is so thin as the well was 90 feet deep and is at least 300 feet from the house. I am providing a 110 outlet at the old well spot with this wire. I know that at 300 feet and this thin of wire I am going to have a serious voltage drop, and it may be unusable. My hope was to tie two hots up to increase the amperage (the breaker can be wired either way, currently wired in 220 configuration but).

What the intent is to power the minimal electricity the inlaws camper takes (small fridge is the biggest draw).

It has worked fine in the past, but the wire was accidently cut so while I am working on the system, I thought I would consider this upgrade.

 

[CliffordK]

Does the well require 220V? Dropping to 110V could cause you major problems.

Note that 220V can be used just fine with 12AWG wire, as it essentially puts the same amps on each leg as 110V power.

However, I assume your inlaw's camper isn't wired for 220V. Are they just using the camper in the summer, or the winter too? Other power requirements than the Fridge? I'd probably just use it like you had it.

Another option would be a step up/down transformer.

5000 w Watts Voltage Converter Transformer Step Up Down | eBay

Many stores have 10AWG, 100Ft extension cords (The HF female plugs are worthless). They are kind of expensive, but you could run 10AWG extension cords to the trailer. You could, of course, also buy flex wire and make your own too.

 

[woodlandfarms]

Sorry I wasn't clear. Well is abandoned. Just the wiring remains. Currently Black and Red legs on Respective 20 amp breaker, Yellow leg now tied to Nuetral and Green leg to ground. This whole mess runs to our orchard (old well site) were I put in two 120v outlets (one for each leg). As no one ever uses more than one leg, this is where I started to get my hairbrained idea.

What I am trying to cypher is wether tying the red and black leg together and onto one breaker, would give me more current, thus reducing the voltage drop I suffer (80 volts is what my meter is reading when I have a 10 amp load). And wether I can use just the nuetral I have or need a thicker nuetral.

 

[SPYDERLK]

Sorry I wasn't clear. Well is abandoned. Just the wiring remains. Currently Black and Red legs on Respective 20 amp breaker, Yellow leg now tied to Nuetral and Green leg to ground. This whole mess runs to our orchard (old well site) were I put in two 120v outlets (one for each leg). As no one ever uses more than one leg, this is where I started to get my hairbrained idea.

What I am trying to cypher is wether tying the red and black leg together and onto one breaker, would give me more current, thus reducing the voltage drop I suffer (80 volts is what my meter is reading when I have a 10 amp load). And wether I can use just the nuetral I have or need a thicker nuetral.

You will get better voltage with double wire on one side of the circuit, and your loads will run better, but the single wire on the neutral side will be getting hot because it is the return path for the current in the double wire. You really need to run some bigger wire. Minimum 10-2 w ground if you only want 120. If youre digging a 300' trench put in 6-3wground if you can afford it. ... Itll always be there when you need it for solid 30A 120/240 power.
larry

 

[CliffordK]

Nope,
Can't do it.
For a 220V circuit to be split to two legs, you must have different phases.

Otherwise, your neutral gets overloaded.

You could potentially use:
red&black tied together
green&white tied together. Is the Green insulated and the same gauge?
NO GROUND.
Perhaps use a 20A GFCI with a grounding rod.

But, you're probably best with 220V and the step down transformer above.

Or, perhaps a variable step down transformer, although the big ones get pretty expensive.
Powerstat Variable Transformer Type 246 | eBay

I agree.
You can kluge something together for now, but I would really start planning on running new wire as SPYDERLK suggests, and go with as big as you can afford... depending on your long-term expected needs.

 

[FourSonsFarm]

How much current are you looking at pulling through the circuit? You mentioned a small fridge was the biggest load. What else? Lights, TV, Microwave, AC....? And thinking about the future, what is just a fridge and a few things now can turn into more load later. Before calculating the wire size needed, we should really know how much current you are realistically needing. 300' is a long way. And most electrical devices are rated to work at +/- 10 volts. So, 80 volts is a bit low.

 

[Midniteoyl]

You need to upgrade the wire.. Doubling the wires will NOT equal double the gauge, more like a third more. Voltage drop should be less, however, but only on that doubled leg. Your small neutral will still be a limiting factor.

I would upgrade to at least 10ga (8ga is better since you have such a drop), but keep the breaker(s) at 20amp.

 

[CliffordK]

I'm going to reverse my position on this and say to go ahead, it should be fine, although your building inspector would have a cow if he saw it.

PROVIDED BOTH WIRES ARE CONNECTED TO THE SAME BREAKER (which is discouraged). Perhaps you could do it with a pigtail and wire nut.

Anyway...
Say you have a single 20A breaker.
Then the whole circuit will be limited to 20A, independent of the wire configuration, and no individual wire would get over 20A.

Now, with the data you've given.
About a 40V voltage drop at 10A (assuming 120V at source).

V=IR
And your resistance is about 4 Ohms over the circuit.
That means that each leg has a resistance of about 2 Ohms.

Now, if you double the wires on the "Hot" leg, then you halve the resistance on that leg, to give you about
1 Ohm on the hot leg, and 2 Ohms on the neutral leg.

Add it together, and your circuit resistance should be about 3 Ohms, and your voltage drop would be 30V rather than 40V, giving you a final voltage for the circuit at about 90V at 10A.

You're still running 10A on all the legs, well, actually, the Neutral leg still gets the 10A, the "hot legs" would get half that, or 5A on each one.

You just couldn't install a larger breaker than the 15A or 20A breaker.

Even if the circuit was a mile long, as long as you're feeding less than the 15A or 20A into it, you should be fine, although some of your devices might compensate for the voltage drop by sucking more power.

If you doubled the neutral too, then your resistance would be halved on both legs, and your voltage drop would only be 20V rather than 40V, giving you about 100V final voltage at 10A.

Is any of this in conduit that would be easy to pull the old wire and put in new?

Also, keep in mind that only about 2/3 of the power that you're paying for is getting to the destination. If used lightly, that wouldn't be an issue, but if used continuously, then the cost of the power loss could add up.

Anyway, it is up to you. As long as you don't oversize the breakers, you should be reasonably safe, but certainly not considered Kosher.

 

[Midniteoyl]

Resistance is not halved by doubling the wire in AC circuits..


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http://www.daycounter.com/Calculators/AWG.phtml

 

[mcandrew]

Id say its at least pretty close. There shouldn't be any skin effect at 60hz, and if its stranded wire, theres a lot more skin.

 

[SPYDERLK]

Id say its at least pretty close. There shouldn't be any skin effect at 60hz, and if its stranded wire, theres a lot more skin.

There ya go. ... Not sure stranded will be analogous to multiple single conductors tho. - Not that this is an issue here.
larry

 

[woody]

wow, this is interesting but what if he doubled the hot wires say tie the red and black together double the neutral and ground tie them together and then drive a ground rod in at the old well site giving him a path to ground? would this get him by until he could do better with larger wire?

 

[SPYDERLK]

.,,Yes.

 

[FourSonsFarm]

The National Electrical Code (NEC Article 310.4) states that for wires to be run in parallel that they must be of size 1/0 or larger. Granted no one will be coming behind you to inspect the work. One thing to keep in mind. As the load on the circuit goes up the voltage will go down, inversely proportional. Also not a good idea to place a second grounding rod at the old well pump site. If for some reason the path to ground is of less resistance to the new rod than the old one, then the whole house would start grounding to the rod at the old well pump site. The two number 12s or 10s in parallel would hardly be enough. All that being said, it should work for light loads, but keep an eye on things. Definitely not the best long term solution. Just my 2

 

[hosspuller]

Another reason to pull new wires. A supply voltage of 80 - 90 volts is bad for refrig compressors. The lowered voltages produces heat in the compressor windings. The added heat shortens the life.

 

[woodlandfarms]

Well, I went to HD today to do some research. I have 14-3 for the well wire (what a friggin joke, can't believe it is what they used, even if the pump is only 1/2HP).

I think I would need 10-3 to make the 300 foot run. It is $4.09 per foot. As this outlet is seldom used (too much in my opinion as it provide electricity to the inlaws camper if you get my subtle dig) - I am not going to run new wire at this point. Not worth it Financially.