220 Volt Wire Run Info Needed

While it's true that a 220 volt circuit only requires two hot conductors and a ground, the objective of this project is to provide 110 volt service. A common conductor will be required for 110 volt service.

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Yes, 6 gauge wire is appropriate for most 60 amp circuits in homes, but wire size is also a function of distance. For distances over about 150 feet, which are seldom seen in residential settings, a heavier wire gauge will be necessary to prevent voltage drop for a 60 amp circuit.

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............I believe I'd just have the co op set a power pole next to the barn and add a weatherhead to roof and establish 100 amp service then he can do whatever he wants ! Much simpler , fordy

Sounds expensive.

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Really expensive since if anyone has read through all of the postings that I have made, I have all the wire required FREE and Clear. I have the service FREE and Clear to go on the barn, and I understand how to hook it all up. What I want to make sure of is that I MAXIMIZE SAFETY in what I hook up - therefore I will not run more than 20 amp (tables say up to 22.5 amps) 220 to the barn. This should therefore support two 20 amp 110 circuits at the barn, which in reality will seldom run more than a light in the barn, a light in the chicken house attached to the barn and maybe a run to another barn where I need to have a light. All the lights will connected to timers that will allow them to run in the winter for several hours to allow the animals to have light to eat by. Occasionally, it will support a heat lamp for baby lambs and a set of electric shears. Installed on the lines there may be several fence chargers, but they use virtually no electricity at all - just enough to charge a capacitor to charge the fence wire.

If you use 6 gauge wire and breaker it for 20 amps, even a 350 foot run will remain cool.

Disclaimer: At full 20 amp draw (4800 watts) you will observe about a 9% voltage drop, but it's doubtful you will ever draw that much. To prevent voltage from dropping more than 2% at full draw you would need to use #2 or #3 wire, which would cost you an arm & a leg. Trust me, you'll be delighted with a 20 amp service and 350 feet of 6 gauge wire for the service you describe, even for the heat lamp.

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After all that and it's been real interesting. Can your 20 amp circuit breaker handle 6 gauge wire or are you going to have to install a junction box to bring the proper size wire to the breaker?

The 50 amp 220 breaker that feeds the #4 wire that runs my welder handles the #4 wire just fine. At the terminal end the wire goes into the lugs on the service subpanel. The #6 wire goes into the 220 20 amp breaker at the service in the shop/garage. At the barn the wire serving the lights, etc is just 12 gauge like in a house. #6 is not THAT BIG.

Keen observation The QO120 that I just looked at had a lug rated up to #8 AWG.

Assuming that the 22.5 rating from the engineer is correct, you could go to the next larger available size. Now if this is going to the route of 220/120, that would be a QO225 ( 25 amp breaker) but it too has a limit of 8 AWG ... as does the 30 amp.

But, technically, once you install the 20 amp breaker .... it becomes a 20 amp circuit. Just as others have mentioned that a larger sized sub-panel is irrelevant due to existing limitations, #12 AWG could be run to a distribution block ( or sub-panel) that allows the connection of the #6 AWG conductors to prevent the voltage drop over the longer run ... even via a 40 amp breaker in the sub-panel ( it is still limited to 20 amps).

The breaker is intended for no other purpose than to protect the conductors.

Never caught whether the conductors were AL or CU but did see some amperage cited as if using the 90C rating .... which also returns back to the termination being rated for such. Using a 90C rated amperage on a wire that is terminated to a 75C terminal ( typical) does not apply ... it is limited to the 75C conditions.

AL at 75C is rated for 50 amps.

My whole perspective came from the title of 220 volts, 3 wires .... with a goal of 110 vac loads. That is where I brought up the 4th wire.

As others have mentioned, Ye bond the ground to the neutral AT the source. From that point on, you have a grounded and a grounding conductor ... one does not arbitrarily add ground rods as you are creating issues. If a ground needs to be enhanced, you add additional ground rods at the source ... at 10 foot intervals.

The system ground is it ... it is to be maintained throughout the system. Adding a separate service is totally different from a circuit originating from an existing service,

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Remember, wire gauge is a function of both amperage and distance. Amperage alone doesn't tell the story.

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We are rapidly degenerating into the realm of "If you metamorphosize the binomial aspects" of this wire run.

Safety first. Electricity gives few second chances.

Buried metal conduit would need to be either Ridgid, or IMC, basically the really heavy galvanized threaded pipe. It is heavy, extremely expensive, and difficult to work with. It can also degrade quickly in the wrong soil conditions. Although it is "legal" to use the conduit as a ground in certain conditions, it is generally not considered best practice, and avoided by most decent electricians.

Given all the wrong circumstances, this can be fatal. Which is why I clearly stated that it has been a code violation for a few decades now. When you create separate, unbonded ground points in any electrical system you create a multitude of safety issues. The specific issue created is called difference of ground potential. A simple example is that is similar to one that I have actually experienced in the field. You incorrectly, and illegally, install a three wire subpanel with a separate ground rod in the barn. You decide to add a lightning arrestor to the top of the well, since you lost the pump recently, when lightning struck. You are working half way between the house and barn, drilling a hole in your well casing.with your trusty fifty year old, 1/2" drill. The cord is plugged into the new barn service. As you are drilling, you are unaware that the old drill is shorting to the metal handle. You now have the drill in one hand and touch the well casing with the other hand. The power in now grounding through your heart, and within a minute, your dead. It might seem dramatic and odd, but it can and does happen. The reason it happened is that you created a difference of ground potential by randomly adding unbonded ground points to the system. Instead of the short tracking back through the three wire extension cord, quickly tripping the breaker, the path of least resistance was the well casing, which was not common to the barn, since you separated the system by installing a different ground at the barn. You can have as many ground points as you want, but they all must be connected together, therefore, as I stated earlier, the subpanel MUST be fed with four wires, and the neutral MUST be an unbroken path back to the service.

I put all underground wire in PVC conduit, no exceptions. The money is in the wire and the labor. Plastic conduit is cheap, and digging up cable damaged by settling fill is a stupid waste of time. It is possible to push cable into lengths of PVC as you go, but there is one really important trick to pay attention to. It is real easy to accidentally glue the wire to the pipe if you don't pay attention. Unlike plumbing installations, the trick is to only use glue, sparingly, on the male end of the pipe. I go so far as to not get any on the last 1/4" of the end. When you push the conduit together all the excess glue is then extruded OUT of the joint, and none lays in the pipe. The objective is not to seal the pipe and make it waterproof, since you are never going to suceed at keeping water out, and it doesn't matter anyway. If you get glue inside the pipe, it can actually weld the wire fast to the pipe. I had a helper do it to me on a well line install and you literally can't break it free. The other issue is to make sure that no dirt or pebbles get into the pipe as you go along. I always have plenty of rags and duct tape available to keep things clean and sealed.

Since I'm a simple dirt farmer, didn't want to comment on stuff I don't know, but was curious on that - didn't know you could use metal underground, never heard of that 'here'. Would think it would rust out fast.

--->Paul

..................When I referred too using burried metal conduit as a 4th. conductor , I wasn't implying that it could be substituted as a 'ground' ! I had just assumed that there were some types of metal conduit approved as "buriable" since we had metal conduit long before we had PVC . A good ground would obviously be needed at each end of the "run" . , fordy

Pulling wire through. Conduit while assembling it is another code no-no.
Proper way is to assemble the conduit completely, then pull the wire through.
I know a lot of people do it wrong but code practices one from the failures analyzed. There will be sound reasoning on why they want it done this way.
If you ever visit a burn unit at the hospital you will find the one place you never want to see again. Do it right and be safe doing it. Safe use should follow.

LOL, now I got a question!!

My dad has a garage about 120 feet of outdoor Romex 10 gauge solid. We ran it on a 30 amp breaker at the service, and various 25 amp fuses in a old Pacific fuse panel.

It was only grounded at the service end.

As time went by, various thing were added to this circuit in the Garage, a freezer and a 5 HP compressor. The compressor startup would cause a MAJOR voltage drop, causing severe flicker in the florescent lights.

Now, we have "converted" the Romex line to 220 volts, installed a double 30 amp breaker at service(black/white live ground is ground), and split off the two 120 lines to various circuits in the Pacific fuse panel in the garage.

Installed a 4 ft ground rod at the garage fuse panel. Now the 5 HP compressor does not cause a voltage drop.

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