I’m running three wires ( AL ) down the mast to the panel. Does the neutral have to be insulated? The mast is 2″ heavy wall.
I’m running three wires ( AL ) down the mast to the panel. Does the neutral have to be insulated? The mast is 2″ heavy wall.
The RealTruck AMP Research Bedsteps give you easy access to your truck-bed storage.
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Get home building tips, offers, and expert advice in your inbox
Fine Homebuilding
Get home building tips, offers, and expert advice in your inbox
© 2024 Active Interest Media. All rights reserved.
Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.
Get home building tips, offers, and expert advice in your inbox
Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.
Start Your Free TrialStart your subscription today and save up to 70%
SubscribeGet complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.
Already a member? Log in
Replies
Absolutely!
If I am understanding your question correctly...
I am assuming you wish to install or upgrade to a new main service panel. There is NO neutral!!! Those are both hot wires (Each 120 Volts 180 deg out of phase) This means that the potential difference (voltage) between them is 240 Volts. The bare twisted wire is your ground.
If this is for a subpanel...Notch is correct...needs insulation. Be Careful.
Are you sure that's not a neutral? (My Code Check is out in the truck and I'm tired.)In my area there are always the two hots and (on an overhead service) a bare wire coming from the Edison service, and that bare wire is also run (insulated) into the meter box. I've always thought that was a neutral. The ground(grounding electrode conductor(?) is connected to a ground rod or the plumbing main.And on the sample pages for CodeCheck, in talking about the service equipment,in the lower right corner of the 1st page they say "Identify neutral at both ends . . . . . . . . . . .[200-6b]"http://www.taunton.com/finehomebuilding/pdf/service_equipment.pdf
View Image
Sojourners: Christians for Justice and Peace
"I am assuming you wish to install or upgrade to a new main service panel. There is NO neutral!!! Those are both hot wires (Each 120 Volts 180 deg out of phase) "120 volts with respect to WHAT????It is with respect to the NEUTRAL. The 3rd wire is connected directly to the NEUTRAL connection on the transformer and is a NEUTRAL.It's whole purpose is to to return the difference in currents in the 2 hots.As to the orginal quesiton I don't know.SE cables the neutral is not separately insulated. And the POCO triplex uses an uninsulated neutral.So my guess is the neutral can be bare, but again I am not sure.
Thanks for clarifying...I just wanted to make sure he didn't think one wire was not hot.
Farmer,
Yes, the neutral conductor in the service entrance mast has to be insulated.
The correct term for a neutral in a solidly grounded system (which is what we have in N. America) is "the grounded conductor". It is a current-carrying conductor, and is the low-potential or return conductor.
That is VERY different than a grounding conductor. There isn't a grounding conductor in the drop or underground service lateral of a 240/120V, single-phase, three wire service.
Anyway, about the neutral in the service mast. There are two reasons the grounded conductor ("neutral") in the mast has to be insluated is that if the mast is steel conduit.
First, contact of the conductor (either copper or aluminum) with the steel conduit will lead to electrolysis because the dissimilar metals are in contact. The alumium will lose to the steel, and the steel will lose to the copper. Second, if the grounded conductor is uninsulated and in contact w/a metallic conduit, and there's an break or poor connection of the neutral between the panel and the utility transformer, the potential of the metal conduit will rise (to the supply voltage, if the neutral is broken).
This obviously presents a real safety hazard. The uitlity transformer is fused on the primary side, usually at 10,000 amps. If it's a poor connection, or partial break in the neutral, it's possible that not enough current will pass to cause the fuse to open. Fireworks time.
If the conduit is non-metallic, the above two reasons don't apply. But the NEC still requires any current-carrying conductor in conduit to be insulated.
Cliff
It is my humble opinion that when building a service , if you need to ask complete strangers on a web-site( even though there are some very bright people on this one), about how to do it, you shouldn't be doing it...or you should find a local expert.
sorry, but thats how I feel.
Edited 8/8/2005 10:42 pm ET by bos'n
I'm going from a three wire service to a four wire panel. Those old screw in fuses my old man would put a penny under are gone. My ground has gone from one 4'x1/2" to three rods 16' from the first to the last. The new ones are 8' x 5/8". My service drop is going from 8'6" off the ground to 12'6".
My 4 appliance circuits will now be in emt. Those old knockouts that did not have romex connectors in them are gone. The service cable will be in 2" HW instead of just following the wall up to the hole.
I think I've spent $400 just on new parts. In fifteen years of farming, if you discount the appreciation in land, I've never made a profit.
The nearest local sparky is 40 miles. What do you think he'll want just to bring his truck down the drive way?
In the future I can add a surge supressor to my garage door. I can add a transfer switch. I can add GFI breakers with an EGC connection.
This is my first time wiring the service. But, I've trailed many a sparky. You won't find any flimsy plastic boxes in my garage. You won't find where that good-ole-boy forgot to hook up the egc either. There ain't no sticking the wires into the speed holes on the back of recptacles. I buy the $2 receptacles instead of the $0.50 models.
I think farming is more dangerous than roofing. I'm sure my new panel/service will be safer than ever. My buddy the electrical contactor says he's got union guys working for him that make over $125,000. I've seen his house and can't hardly image what he's making. Some of you boys need to get a grip.
Big Macs - 99 cents
I knew I would get blasted for that comment. But I stand by it.
You say you have a contractor buddy. He is the guy to ask for advice. You may be able to do the work, but when you start building the foundation of your entire electrical system-your service- and you have questions, you have to go to a local expert for advice. Why? Because there are things that differ regionally. For example, when we had a big blizzard here in Omaha a few years back, our local public power Co. had to get help from around the region to get power back on line. Some local contracters hired travellers to help with the work load of rebuilding busted up services...the result?
A buddy of mine works for the power Co. He said that they are still finding wierd stuff that the linemen from other places did when they came here to help. An electrical inspector told me that he had to turn down some technically correct services that travellers built, because the local utility wouldn't hook them up. They just didn't follow the utility's standard.
I'm not trying to say that you don't know what you are doing. I'm trying to say that the other people here on this web site don't know your local laws and utility requirements. Nor do we know your environmental situation. Your local friend does.
The other thing I'm worried about is the language issue. I teach apprentices in a local trade school, and I know how difficult the specific trade terms are for various wires, conductors, cables, etc., especially when you are describing parts of a service. The input you were getting in this thread sounds very confusing, and you shouldn't risk a mistake based on a misunderstood answer to your question.
It sounds like you are making some major improvements to your electrical system, but ask yourself... Would you rather drive a Model "A" that is in working order or a brand new pickup with one lug nut on each wheel?
It is not my job to tell you that it can't be done. It's my job to tell you how much it will cost. Here, sign this change order.
I agree with the post about "talking to strangers" - this sounds like an easy job for your local electrician - had a "professional" visit to a house where the husband wired the 220 for the wife's new dryer using the lugs on the top of the breaker panel - in other words, wired directly from the input from the meter - lucky the wife was doing laundry in the afternoon. The socket melted and the surrounding wall were only slightly damaged by resulting FIRE!!!!!
Don't forget to mark each end of your neutral with some white elec. tape
Hi,
The neutrel conductor must be insulated and marked white at each end. You may also want to check with your utility provider to see if they also require you to run a ground conductorwith the rest. If they do, it will also have to be insulated and marked green on each end. it is required it in this part of NE North Carolina. Basically, everything in the conduit must be insulated.
pah51
"You may also want to check with your utility provider to see if they also require you to run a ground conductorwith the rest. If they do, it will also have to be insulated and marked green on each end. it is required it in this part of NE North Carolina."Are you talking about an EGC or grounding electrode wire?And what would it be connected to on top of the mast?