ECN Forum Forums Photo Discussion Forums Photos for General Discussion XXXX the Carpenter

I'll 2nd Paul,
one would think even the most noviced will take note of proper installations.........

Thanks for the pointers!

I figured as much, re: no "flying splices" really allowed at all. So, basically, if I want to move an outlet box over a foot and not have a "blank cover" in my wall, I need to pull a new piece of wiring from the next box on the "short side" to my new location and shorten up the wire exiting the box as it will be a foot too long once the box has been moved.

Or did I misunderstand and I could basically use the old outlet box as a "splice box" and screw a flat steel cover over it (or plastic, if it's a plastic box), re-attach it to the wall stud so it fits behind the drywall and cover it up with a chunk of drywall? Or are there special "splice boxes" available which can be "buried" behind drywall? Or must I re-pull the wire or have the "blank cover plate" on the old outlet box?

The houses I'm looking at are 1920's - 1940's construction, most have had their electric service upgraded, no old pushbutton switches left that I've seen yet. Lots still have fuses, though.

Oh, reminds me: I've seen this twice now in places I've been looking at. The original main panel is in place, complete with the original 60 Amp main fuse block and circuit fuses. Follow a wire or conduit from that box and you find a smaller sub-panel with 4-5 breakers in it. Am I to assume that the sub-panel has no main breaker (all were 15-20 amp breakers) or can one put larger fuses in those old main fuse blocks? I've also seen another newer fuse panel (a Square D 100 amp one) that appeared to have four main fuse blocks with two circuit fuses next to each one, and a sub-panel with breakers. In both cases, the ratings on circuit fuses and breakers added up to more than the "nameplate rating" on the main panel. Heck, on the first one I saw that was like this, the sub-panel alone had more breaker amps than the main service panel was listed for!

Is this code? Common? Stupid? (I'd bet on the latter two.) Seems to me you'd have to either run a separate main breaker for the sub-panel or replace the main panel with a higher-rated unit.

Thanks,
-cajun

You can not have *ANY* splices or boxes burried in the wall - all have to be accessible. If you move a box, you will either be lucky and move it to the side where you will have extra wire or more likely will have to rerun the wire from the previous box or from a location where you can add an accessible box (attic, crawlspace, inside a closet). Either that or leave the recepticle in place and run a wire over to the new one.

As for the subpanel on an old fuse panel, it may be fed from one of the branch fuses in the main. You can't just put larger fuses in the main block. The panel has a max limit and it also depends on the size of the feeder.

The best way to clean this up would be to either replace the fuse panel (and service) with a new 150 or 200A service or at least put in a new service and feed the old fuse panel as a sub-panel (splitting neutral/ground in the process).

Cajun,

I recommend that you hire a local Electrician (that is familiar with residential wiring) to take a look at any house that you may be interested in purchasing. He should be in a much better position to explain things to you than we could here. It is not within our scope to delve too deeply into these types of things on this Forum.

Bill

Bill, n1ist,

Thanks for the info. I will most certainly have a professional inspect a house I want to buy.

Okay, all clear on the "no buried splices" part. Figured, but wanted to know if there were any "loopholes" in the code that would provide a safe method to bury a splice. Oh well.

As for the fuse box stuff, I'm mainly curious about the setups because they just "looked wrong". Best get my terminology straight first, eh?

Correct if necessary, please:

Main fuse or breaker - the first thing the power "sees" when it comes out of the meter.

Branch fuse or breaker - the over-current control devices for circuits fed off of the main fuse or breaker.

Main panel - contains the main fuse or breaker and the first group of branch fuses or breakers.

Sub-panel - another panel used to install more branch fuses or breakers when the main panel is full.

Okay, now the questions:

Can the branch circuit fuses or breakers total up to a higher amperage capacity than the main fuse or breaker? I wouldn't think so, but I can see the reasoning behind why it might happen: "Oh, we never turn EVERYTHING on at once..."

How can you run ~85 amps worth of sub-panel breakers off of a branch circuit fuse in a 60-amp main panel? Or off the main breaker, for that matter? I don't think either sounds like a good idea.

If the main panel is in a location that precludes cost-effective replacement, can one run another "main" panel (in parallel to the original main panel) in a more accessible/larger location with its own main and branch breakers? (assuming the from-the-street service is of sufficient capacity and/or has been upgraded)

Last question, and here's where you get to jump all over me.

If a DIY-inclined homeowner wires in a bunch of auxiliary circuits to, say, a garage workshop, leaves all the wiring and connections properly accessible (or doesn't put the drywall on yet in the case of the wiring), leaves sufficient wire at the location of the main panel and leaves it tied-off and physically unconnected to the mains, would a licensed electrical contractor be willing (in general) to come out, inspect the work, correct where necessary, and do the final hook-up which may include getting a service upgrade?

Is this generally more or less expensive than just having the electrician do all the work in the first place, assuming the homeowner is used to reading federal codes and follows the NEC to the best of their ability?

Or is it just plain insulting to the electrician and/or most won't do it because of liability reasons, not wanting the homeowner staring over their shoulder to see where they (the homeowner) "did it wrong and how", etc.?

That'll probably be all for this thread from me, other than a "thanks" or a request for clarification. Probably go over to another "forum" on this board to ask the more theoretical questions...
-cajun

Bill,
He has asked similar types of design/build questions on an air conditioning BB.

Cajun,

We can run circuit-breakers with a combined rating which is greater than the incoming feed to the panel. It is based on a principle known as "diversity," which as you have touched upon above is the idea that everything will not be running simultaneously.

To take a simple example, suppose you have six wall receptacles (normal 15A types) wired on a branch circuit. The protective device will be 15 or 20A, not 90A. To wire the whole house on the basis that every outlet is loaded to maximum would result in a very expensive installation which would almost never be fully loaded in normal use.

That's why the NEC (and the equivalent codes we have in other countries) specify certain circuit configurations to take into account this diversity.

As Bill has pointed out, however, this is getting into quite a complex area which is best left to those with the necessary knowledge and experience.

Hmmmmmm. Looks faaaaaaaintly familiar!

Ya got me Wolfdog, I'm on the HVAC BB a fair amount, true.

I ask questions because I'm curious and like to know how much I don't know about things.

Note the phrasing on that.

Sometimes I'll write like a knowitall (I think we all do that sometimes) but I try to keep in mind that I've little to no practical experience or training in either the HVAC or electrical fields. I do have a BSME, so I can usually understand the technical side of things once I've seen enough context, but I am not going to try and design/build/install my own HVAC and/or wiring system! Though, being an avid DIY type and experimenter, etc. I might try a thing or two in a garage, or at least check for "obvious" things like voltage at breaker, voltage at motor, anything smell burnt, gaping holes anywhere, etc.

There's also the CYA factor, too. No offense, but on both this board and the HVAC board I've heard many a story about a "hack job" by some licensed contractor who likes to cheat a bit and I simply want to know enough that by the time I am in a position to hire a contractor I'll be able to understand what they're telling me and have a better than average chance of catching a rat.

I'm also trying to learn what it is that y'all DON'T like seeing/hearing from your customers or potential customers, as I would rather not PO someone who is working on an expensive piece of equipment or wiring or what have you.

pauluk, thanks for the info. Those panels just looked odd to me, is all, and I was curious. I'll certainly be hiring an electrician because I doubt whatever place I get will be wired to support a welder, etc. in the garage... Especially if it has the original 60A service!

Sorry to ruffle any feathers.
Thanks all the same.
-cajun

Cajun,

I'd like to give a little more in the way of explanation here. As I see it there are a plethora of DIY websites out there that cater to the novice, I have mixed feelings about that, and cannot truly recommend them (or any website forum) as a place for the inexperienced to get information on potentially dangerous things, but I would like to keep this a place where people involved with the Trade or Theory, etc. etc. can interact with each other and thereby benefit.

Some DIY questions may be tolerated by most anyone here and fielded in the appropriate manner, but a BIG problem is that one begats another and another until it is like DIY Central here. Many of the people seriously involved in the Trade and/or are able to best help us will get tired of answering (or very leery about answering) and seeing these types of questions and just leave. It is my personal goal to not let that happen.

Bill