Hello,

I am a 100% DIYer and very competent in my work. I have read a lot here, more lurking, and this board is great for information. I am thinking about doing a major job here on my house and would like some feedback.

A few nights ago a neighbor had some sort of an electrical anomaly which caused a rather serious arc in their outside disconnect just below their main service meter. They were lucky since it was mounted on an exterior brick wall. Had the run to their main panel been shorter, there is a good chance it would have arced in their basement causing a fire.

Since then, it got me thinking. Our main service meter is within the 10' mark of our electrical panel. We have 200 amp service. I was kicking around the idea of installing an outdoor disconnect for a couple of reasons.

1. I like the idea of a flareup happening outside of the house on the brick wall instead of against our wood joists.

2. Our main electrical panel has had some rust/water damage that was caused year before we purchased the house due to water entering the main service head and slowly dripping into the box. The issue allowing the water in has been corrected, but the bottom of the box is very rusted. Also, a small portion of the neutral bus bar has rust coloring. All neutral lines have been moved away but that makes the rest very crowded. As a result I would like to replace our main panel with a larger 200 Amp box (probably a Square D QO Load Center, PLEASE LET ME KNOW IF YOU HAVE PREFERENCES OF OTHER BRANDS AND WHY). This won't be until I have it in my budget and I just figured that the main outdoor disconnect would allow me to replace the main service panel at my leisure without needing to coordinate power shutoff with the electric company, just with the city inspector. Dominion is very unreliable around us and I would only like to rely on them once.

3. I do a lot of renovation, and en up making a lot of changes to the main panel. I am paranoid about the fact that live lines still enter the service panel even if the house is shut off. I just like the ability to shut down the lines from the outside so I don't have a stray anything come in contact with something that it shouldn't.

4. I am planning on installing a natural gas generator at some point in the future. Again, the outside disconnect would allow me that additional level of comfort in working with the wiring.

I understand electricity and how it works (I am EE from college). I also worked during summers in college for a master electrician, wiring homes, additions, and garages. I understand the principals and have extensive experience with home electrical wiring. In the past I have installed 100 Amp sub panels and have replaced entire houses knob and tub as well as BX wiring with modern wiring. I do my work with permits so I have a city guy looking over my shoulder.

With all of this being said, is installing an outside disconnect for my main service 1. adviseable based on my reasoning above, and 2. something I should be able to handle given my past experience?

Thanks for the advice.

Oh, I also like the idea of using Arc-D-Tect AFCI breakers for the majority of my wiring. Does anyone have any feedback about these? Do they tend to swallow X-10 signals?

Actually, installing an outdoor disconnect between the meter base and service panel would only increase the chance of faulty wiring (as was the cause of your neighbors fault). Also, no protection other than the utility transformer will interrupt the fault and you could affect neighbors electrical supply.

I believe this practice to be very dangerous. Some areas do not permit a customer's service to be provided with more than one service box (which would rule out the generator installation). You'd have to check.

I'd rather do electrical modifications at the panel where it is designed to safely install a new circuit than fool around with an unprotected outdoor disconnect that will take down all my neighbors if something shorts out!

Who's going to get sued if neighbor X breaks her leg because she fell down the steps when the lights went out?

I am not really sure how bhayne perceives your situation, and his reasoning for his answer.

Mine answer will contradict his, and mine is verifiable.

If your service panel was more than ten feet away from the meter, measuring the service cable, you would have had a disconnect at the meter, as required by NEC's ten foot tap rule. Installing one in your situation will exceed code requirements.

I understand you reasoning, having the cable that enters your home protected by a circuit breaker. This will do exactly what you expect, eliminate the live line running through the structure, and allow the panel to be completely de-energized when you want to work inside it.

I doubt you will be able to just install the disconnect , and not upgrade the panel at the same time. You may, just will be up to the local inspector.

And , if you do want to install a 200 amp panel, the meter and service conductors feeding the meter need to be upsized to 200 amp rating, and would not be able to protect an existing 100 amp panel, unless you have a 100 amp breaker at the meter, and then upsize that once the panel is upsized.

If the generator you plan on will handle the entire home, you can connect the load side of the new exterior breaker to a manual transfer switch, that would also be fed by the genset output. Or you can use a GenTran type transfer panel to handel specific circuits at the breaker panel.

Be advised, some sort of transfer equipment must be used to tie a generator into the home's electrical system to avoid any chance of feedback out into the utility grid.

I have not heard of any issue with AFCI devices interfering with X-10 devices. They only impose a signal onto the power lines, and do not cause any arcs.

Square D QO is fine, good choice.

Thanks TKRussell,

I also don't see how adding an outdoor disconnect will impact my situation negatively, your response is more in line with what I had expected as well as with what I know of electrical code.

I already have 200 Amp panel in my home, so adding a 200 Amp disconnect should all be fine.

The one thing I am wondering about is indoor panel replacement. Why do you think I will need to replace the indoor panel at the same time as adding the outdoor disconnect? Like I said, I want the added safety of the outdoor disconnect, but don't have the budget to replace the panel inside yet. Do you think the inspector will say "Looks fine outside but the old panel has to go".

The generator will not handle the entire home, it will only handle a small selection of about 4 circuits. A few lights, refrigerator/freezer, air handler fan, the computers that I run as a home based web host, and home theater, you know, the important stuff (jk on the home theater). I will be getting one of the smaller ones. I figured those circuits would live in the generator sub panel. I'm familiar with the generator installs and transfer equipment. I have some good UPS devices on the computers since the switch-over is not instant.

Oh, also, on the AFCI circuits, are they worth it? I know GFCI can be a life saver, and since 1 circuit per room is my rule of thumb just to be safe, I do the GFCI for each bathroom circuit at the panel. AFCI just seems like good insurance. My house is 125 years old and as much protection against a fire as I can get it good. Any fire damage would be catastrophic due to what it would do to original details that just can't be replaced.

I was figuring on using http://www.amazon.com/Outdoor-Main-B...1?ie=UTF8&s=hi for the disconnect.

Thanks for your reply.

OK I did not get that the panel is already 200 amp. So then no problem, just replace the panel soon to eliminate the corrosion.

The inspector may require the corroded panel to be replaced, any circuit breakers that got wet also need to be replaced.

The disconnect you chose looks good.

Sounds like you have a good handle on the generator wiring also.

AFCI is now code for any new wiring in bedrooms, just check with local code to see if smoke detectors need to be on AFCI. Some states took exception to that rule, so smokes are not on AFCI.

Ok, cool,

I have no smokes hardwired, all are battery and wireless to my security system. I pulled and replaced all breakers that got wet, so now all we have left is a nasty looking rusted out bottom of the box. It is the sort of thing that is totally functional right now, but if I ever sell the house the home inspector will say "Why is the whole thing rusted on the bottom".

Also, I have my 200 Amp main panel, which is totally full, most of them are slimline already. I also have a sub panel that I installed next to the main panel fed with a 100 Amp (50 two pole) circuit from the main. Doesn't use the 100, so it is a bit oversized, but used #6 w/ground as I was supposed to. I figure when I replace the main panel I will relocate those breakers into the new larger panel. It is already a QO Sub Panel.

I also already installed a whole house surge supressor to protect all of my computers, X-10, and home theater.

Turns out my neighbor's issue was caused by a power surge during a storm that started a fire in their outdoor disconnect box.

Given all I have stated, should I feel comfortable tackling this myself? I have always been afraid of main electrical service.

I never try to make any one comfortable with working with wiring. If you are not 100% confident how to do this or any electrical work, esp at the Main, time to call in a pro.

Having a whole house surge suppression is good, but, you being an EE should also know that surge suppression is best done at three levels, the Main, the panel, and at the device that needs protection. Not criticizing you, just taking this moment to let others know this.

Your statement "fed with a 100 Amp (50 two pole) circuit from the main. Doesn't use the 100,", is curious to me. Are you adding the 2 pole 50 amp CB to think that you have 100 Amp capacity?This is not considered as 100 Amp capacity, only 50.

Once you do decide to replace the panel, install a 40 circuit panel, the largest QO 200 Amp panel available. If you have any more than 40 circuits, you will still need to use a subpanel.

Negative facts aside (exposed wiring, outside access and exposure, vandalism, 2 mains on a single feed, ect); it is not standard wiring practice.

Fear and safety are not related. There is no additional safety for the outside disconnect (if you throw the mains on the panel, it is dead). If you are not comfortable working on a panel, you should get an electrician. As an inspector, I would not permit such an installation even though it may not violate code.

A DIY should know their limits!

tkrussell,

Sorry, mispoke on the "100 amp (50 two pole)." I installed an attic disconnect for the furnace air handler which is fed from the panel by a 100 amp 2 Pole breaker 1", and a sub panel fed by a 50 amp two pole slimline. The top slimline in both rows is just a single, which ensures that each pole of the other two pole slimlines are on alternate legs. This should sound a little more appropriate, I think I was rushed in my last post and not paying attention.

Also, don't worry, I never feel comfortable working on wiring ;-) I feel competent, but it still intimidates me and I respect it. I think the first problem is when people don't respect what they are working with. I am the same way with the table saw and other power equipment. As soon as you don't respect it, it will bite you. I started respecting electrical the first day I got shocked by it, I think it was my 3rd day on the job with the electrician.

I think at this point I may be leaning towards having an electrician at least give me a quote, that way I can weigh the DIY benefits.

I also want to second what you said about surge supression. The whole house supression on the main panel is a good first step to protect things like appliances, and other sensitive items which cannot be protected (such as X-10 devices harwired into the syste,). But on all very sensitive equipment, I typically either install surge protect outlets or use a high quality surge protector strip, such as with computers, stereos or televisions. Also realize that surge protection is just that, protection, but protection that not diffinitively remove the risk of damage. Most consumer supression or protection is rated to a specific limit in joules.

Bhayne, first I just don't see the negative fact that you mentioned. The wiring is already exposed outside as it comes to the service head via an overhead line. The outside access is something I am willing to live with given that these items are built for outside use. As for vandalism, no concern there, it is contained within a walled back yard. I just don't understand your reasoning behind what you've stated about my setup blowing out neighbors lines. I have seen this setup a couple of times in our area, two of which were city approved, so I am assuming the inspectors would allow this if it were the risk you are stating it is.

I do believe there is an additional safety with an outside disconnect. As I stated, the neighbors situation was caused by a surge on the line which ended with a rather serious arc and fire in their outdoor disconnect. Had this scenario happened to us, the arc and fire would have occurred in our based against wood beams.

My reasoning is similar to the safety device that my table saw runs. It is a device which is attached to the blade that if it senses a specific change in the electromagnetic field associated with the item touching the blade, it immediately applies a brake to the blade. This field is associated with human living tissue contact. The issue is, I don't ever plan on getting my fingers in the area of the spinning blade, but if it happens, the additional safety measure will keep me from losing fingers.

I know my limits on DIY, but I also like to do research and ask questions before throwing my arms in the air and calling someone in. This whole process is all about knowing my limits.

There would be no arc fire because your mains would operate. Your neighbors were probably tampered with. Geesh, two sets of breakers and both faulty. What's the chance?

You wouldn't be the first DIY or contractor I had rewire the place!

Hi

I just joined and would like to compliment both Satanaf and TK Russel for the quality of their exchange.
I would like to raise a subsidiary but important matter regarding the grounding (earthing) situation arisen from the installation of the service outdoor disconnect.
In my opinion, the neutral grounding (tie to ground rods) shall be moved to the service disconnect. The service (existing) panel ground wiring should be modified by disconnecting the tie bar between neutral and ground buses. This requires the installation of either an additional ground rod (preferred method) or modification of the existing tie of the ground rod from the existing panel to the disconnect switch (by running an appropriately sized copper wire in conduit).
If an additional ground rod is installed, local code may or may not permit the tie up of the existing rod to the ground bus.
Accessorily, I wonder whether you should not use a combine breaker and surge arrestor as main disconnect.
Would appreciate your comments.

You are correct, grounding the neutral will need to be relocated to the Main Disconnect. The grounding system will need to be modified once the distribution is modified.

Single point grounding ocurrs at the first over current protection device.

Since the Main will get relocated, the neutral/ground connection that is now at the Main panel with the Main disconnect, must be broken/disconnected.

The neutral wires will become insulated and isolated at the panel, any equipment grounds will all connect together, and be brought back to the main neutral and grounding point at the main with a fourth equipment grounding conductor.

Any ground rods existing need to be connected together, with the one ground wire connecting them starting at the new main disconnect.

The existing main panel becomes a sub panel, once there is a main disconnect remote and upstream of the panel.

I posed the three levels of surge protection,that is normally used in commercial installations, when typically the main,panel, and load are separate.

In the case of a main at the panel, this is obviously not necessary to have wo at one physical location, but now with the proposed relocation of the main, then makes sense to have a surge protector located adjacent to the main. and one at the panel, and the third level at the load.

And I certainly, as I am sure Satanaf does, appreciate the comment and acknowledgement of our discussion.

Better get those ground rods spaced properly and resistive tested. Because to bring a vintage house's service up to today's codes your going to get raked over the coals.

Even Houdini would have trouble pulling this one off!

Bhayne said " As an inspector, I would not permit such an installation even though it may not violate code."
Bhayne, The code is just that, a code. Being a code means you and the electrician must abide by it. No more, No less. I had a building designed and built by a certified engineer . The local building inspector determined some changes were necessary. My engineer asked the inspector to show him in the code book, how he determined the changes were necessary. The inspector answered "It's in my code. ". We filed a complaint with the superintendent of the Building Department. The inspector was reprimanded and I received my Certificate of Occupancy.

IMO
Inspectors should know their limits. If you disagree with the code, you should work to have it changed.

No, the code is just a guideline for electrical installations. The utilities don't need to conform to the codes (because they have professional engineers on staff) and niether do engineers (I am a professional engineer and an inspector). I don't disagree with the code, I disagree with using the code to justify advertising an old house with a new service.

Just think of it; if you were in my place after 30 years of university education and post engineering exams would you place your reputation on the line to say that someone has changed a house's service and brought it up to today's code? The owner has everything to gain and the inspector has everything to lose.

Not likely. And that is why I would not do that. I would just pick and pick at problems until a professional was brought in to bring the service to it's original form. And you will pay for it.

And I have just as much faith in electricians as I do in 'do it yourselfer'. Since I call the shots, I trust nobody. I've never seen an electrician without the white electrical tape- and I know what it is used for!

As you have stated, the engineer is the final word. Some engineers are soft. That's not me. I am not called in for little things (lights receptacles). When I'm called, real problems have to be solved (like houses that burnt down or people injured). If your inspector had a real problem with an installation, he would call me and some engineer would have egg on his face!

I am a retired safety inspector. Every time I signed the pass/fail safety receipt, I put my reputation and my personal liability on the line because that's what I was paid to do.
IMO An inspector's duty is similar to a policeman's, You do not write the law/code but you must enforce it to the best of your ability. Disputes are negotiated and settled by the code/law or litigated in court and settled by the judge.
You indicate you are an engineer But In the U.S. I don't think many, if any residential building inspectors are engineers. Most are experienced in their trade and masters of the code which is written by engineers and enforced by inspectors.

British Columbia had so many 'passed' faulty inspections that they introduced a B1 and B2form in the British Columbia Building Code. These forms must be signed off by a professional engineer for all new electrical installations.

I'm not saying that this has changed much (other than eliminating electrical inspectors) but it does show the activity that engineers are invovled in at the residential and commercial level.

Be thankful that you are retired. If things follow suit, you'd be out a job anyhow!

IMO This sounds like overkill or a make work for engineers plan. Were any inspectors fired for dereliction of duty? In my country, we have had inspectors that have taken pay-offs. Some ended up in Jail. Here, electricians must study the National Electrical Code and pass a battery of tests before they are certified.

It's the same in Canada. Electricians must know the electrical code very well to be certified. Unfortunately, once certified, there is no requirement to keep up-to-date. This is where problems arise.

On the other hand engineers learn nothing about the electrical code. However, it is mandatory that they attend seminars to be refreshed with latest developments. I just organized and attended a three day course in January titled, '2006 Canadian Electrical Code Essentials' and the guest speaker was a CSA inspector that writes and edits electrical codes. Guess how many electricians attended? Zero. Thus, a recent electrician journeyman knows more about codes but I would bet that a seasoned engineer is as good at the code as any journeyman.

Even arc flash is an emerging science and is constantly changing as new developments are discovered. I have heard from some that arc flash is a residential danger. No such thing. If it was, all panel boards, receptacles, switches, junction boxes, etc. would have an arc flash label and everyone in a house would have boarders that could only be crossed by someone designated and trained to operate the light switch. It is a good scare tactic for those that work at Dupont (arc flash clothing manufactures)!

" I would just pick and pick at problems until a professional was brought in to bring the service to it's original form. And you will pay for it."
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"Because to bring a vintage house's service up to today's codes your going to get raked over the coals."

"... using the code to justify advertising an old house with a new service."

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"Bring Service To Original Form." What's that mean? If you're chaninging something you are by definition not having anything "brought to original form".

Why does it matter who does the work if it passes the code _and_ the engineer's opinion?

"And You Will Pay For It." Ahhh... There. That sounds like the REAL motivation!

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Don't know about where ever you are... but in N.C. (NEC based code) generally (and it seems to be the same most everywhere else I have stories from) it is the case that only the NEW work in an "OLD" house (the part that's been changed) has to be brought up to the NEW Code.
Generally I said: You can always end up with a PITA Inspector.
I doubt there are any of those here, though.