110 Wire Guage question

[ljnelson109]

That price for 10-3 sounds like direct burial cable. I paid under $1.00 per foot for regular 10-3 romex just last year. I was doing the same thing, my run was about 275 ft and was to power my own camper. I am not staying in the camper but do keep 2 fridges cold all summer long and maintain the charge on the battery. I ran PVC conduit, and am aware that I should not be pulling romex inside that conduit. There is something completely bogus about the retail price of wire. I can buy 10-3 romex for much less than the price of 4 pieces of #10 (or even 3 #10 and a #12) THHN. I speculated on voltage drop, worried about it, etc. When it was all done, I connected the camper, turned on some lights, fired up the central vac and checked the line voltage in the camper. I am not seeing a significant voltage drop.

Have you thought about warning the out-laws that the current wire is just too small? Tell them that you are willing to do the work (assuming you still are) if they are willing to fund the project. Seems like they would still do better than spending those nights at the nearest campground.

Lee

 

[CliffordK]

If you are just doing 110V, then why not use 10/2 or 8/2.
It is also often much cheaper to buy the wire by the roll than buying it by the foot.
Sometimes good wire will also show up on Craigslist.

I found some of what I think is electrical grade poly pipe/conduit for $20 for about 300 feet at my local recycler. You list LA to Washington. I could probably get you a little bit of what I haven't used yet to somewhere between Eugene and Portland, but perhaps there are other recycling outfits that would occasionally get good conduit.

 

[ljnelson109]

If you are just doing 110V, then why not use 10/2 or 8/2.
It is also often much cheaper to buy the wire by the roll than buying it by the foot.
Sometimes good wire will also show up on Craigslist.

I found some of what I think is electrical grade poly pipe/conduit for $20 for about 300 feet at my local recycler. You list LA to Washington. I could probably get you a little bit of what I haven't used yet to somewhere between Eugene and Portland, but perhaps there are other recycling outfits that would occasionally get good conduit.

Good catch. I saw 10/3 and jumped on the bandwagon. I did use 10/3 because my camper is wired for two 110V circuits. I also terminated to a remote panel in my shed on the way through so I technically could get a low current 220V circuit in there if I had an application. Going back to 10/2, even the direct burial wire is likely to be much cheaper.

 

[SPYDERLK]

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

What path could house ground follow to reach the new ground? Theres not a ground coming from the house in the proposed configuration.

 

[CliffordK]

What path could house ground follow to reach the new ground? Theres not a ground coming from the house in the proposed configuration.

In the main panel, the ground and neutral bars are connected.
In the sub panels, they are separate... So, there should not be a combined path....
Unless both of them touch a common pathway such as bonding to the box.
Of course, going directly to plugs, and they should be separate.

Looking at wires.
Table of Equivalent AWG Wire and Resistance per foot

Wire gauge and resistance (column triplets are the same).

So, for 1000 ft,
2.5 Ohms for 14 AWG
1.6 Ohms for 12 AWG
1 Ohm for 10 AWG
0.64 Ohms for 8 AWG

It seems as if I calculated a bit higher above, but perhaps distances and numbers were off a bit. Anyway, if you went from 14 AWG to 10 AWG, your voltage drop would drop by about a factor of 2.5.

Going from 14 AWG to 8 AWG, the drop is down by nearly a factor of 4. Heat is also a component (see second table on the page), so your 14 to 8 would likely give you very close to the factor of 4 reduction in voltage drop.

Well, I went to HD today to do some research.
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.

Your prices just seem a bit high.

Here is 8/2 Direct Burial, 500 ft, $837 & Free Shipping.
500 Feet UF UF-B 8/2 WG Cable wire direct burial CU - Amazon.com

10/2 Direct Burial, 500 ft, $430
Southwire 500 ft. 10-2 UF-B W/G Service Entry Electrical Cable-13056717 at The Home Depot

Even with the exterior rating, personally I would still put it in conduit.

 

[FourSonsFarm]

What path could house ground follow to reach the new ground? Theres not a ground coming from the house in the proposed configuration.

If everything is wired and working correctly the answer would be none. That being said, Murphy's Law does show up from time to time. I few things that come to mind...

A device that is plugged into the circuit fails from neutral to ground. This wouldn't trip the breaker as the neutral is the grounded conductor in the circuit already. Now the house has a path to the new ground rod via the faulty device.

Many people use Mulberry boxes(die-cast aluminum) for outdoor installations instead of PVC boxes. If the box fill is high and a neutral wire is pinched between the back of the box and the receptacle this is another path to ground. The neutral would pass to the box and than into the yoke which is grounded to the new ground rod.

The next person/homeowner comes along to work on the outlet later on and says, "Who wired the ground to the neutral, that's not right." Next thing you know the would be paralleled neutral becomes a ground and still connected to the ground of the new ground rod.

These are all things I've seen happen over the years. I'm sure the list could go on, but you get the point. If it can happen it will happen.

 

[SPYDERLK]

If everything is wired and working correctly the answer would be none. That being said, Murphy's Law does show up from time to time. I few things that come to mind...

A device that is plugged into the circuit fails from neutral to ground. This wouldn't trip the breaker as the neutral is the grounded conductor in the circuit already. Now the house has a path to the new ground rod via the faulty device.

Many people use Mulberry boxes(die-cast aluminum) for outdoor installations instead of PVC boxes. If the box fill is high and a neutral wire is pinched between the back of the box and the receptacle this is another path to ground. The neutral would pass to the box and than into the yoke which is grounded to the new ground rod.

The next person/homeowner comes along to work on the outlet later on and says, "Who wired the ground to the neutral, that's not right." Next thing you know the would be paralleled neutral becomes a ground and still connected to the ground of the new ground rod.These are all things I've seen happen over the years. I'm sure the list could go on, but you get the point. If it can happen it will happen.

This is where taping and labeling the ends of paralleled wires would come in.
larry

 

[arlen4720]

In case someone is looking from an actual electrician's point of view...

1) As someone mentioned, you can only paralell wire if it is 1/0 or larger, and all of the circuit conductors are of the the same size, type and terminated in the same manner.
2) Driving a ground rod at the remote location is the worst possible thing you can do for safety and eletrostatic damage (lightening). To do it properly, the ground rod would have to be bonded to the rest of the grounding electrode system with a #6 copper wire. Probably not feasable. Even then, it would not relieve you of the requirement to have an equipment ground ran with the circuit conductors IN THE SAME CABLE.
3) All the talk of step up transformers, would be too **** hard to implement considering the grounding and bonding requirements for separately derived systems.
4) for a 300 + foot run you would want #8. Because #10 would still suck for voltage drop on a 20 amp circuit.
5) There is no way to do any of this in a safe, legal way that actually would function....without running new wires.

 

[Midniteoyl]

In case someone is looking from an actual electrician's point of view...

1) As someone mentioned, you can only paralell wire if it is 1/0 or larger, and all of the circuit conductors are of the the same size, type and terminated in the same manner.
2) Driving a ground rod at the remote location is the worst possible thing you can do for safety and eletrostatic damage (lightening). To do it properly, the ground rod would have to be bonded to the rest of the grounding electrode system with a #6 copper wire. Probably not feasable. Even then, it would not relieve you of the requirement to have an equipment ground ran with the circuit conductors IN THE SAME CABLE.
3) All the talk of step up transformers, would be too **** hard to implement considering the grounding and bonding requirements for separately derived systems.
4) for a 300 + foot run you would want #8. Because #10 would still suck for voltage drop on a 20 amp circuit.
5) There is no way to do any of this in a safe, legal way that actually would function....without running new wires.

:thumbsup:

 

[SPYDERLK]

In case someone is looking from an actual electrician's point of view...

1) As someone mentioned, you can only paralell wire if it is 1/0 or larger, and all of the circuit conductors are of the the same size, type and terminated in the same manner.
2) Driving a ground rod at the remote location is the worst possible thing you can do for safety and eletrostatic damage (lightening). To do it properly, the ground rod would have to be bonded to the rest of the grounding electrode system with a #6 copper wire. Probably not feasable. Even then, it would not relieve you of the requirement to have an equipment ground ran with the circuit conductors IN THE SAME CABLE.
3) All the talk of step up transformers, would be too **** hard to implement considering the grounding and bonding requirements for separately derived systems.
4) for a 300 + foot run you would want #8. Because #10 would still suck for voltage drop on a 20 amp circuit.
5) There is no way to do any of this in a safe, legal way that actually would function....without running new wires.

When mindless rules like #1 are thrown in its no wonder people quit listening.
larry