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Question DetailsAsked on 1/5/2014

I have to upgrade a panel with no main shut-off to a 100 amp panel. What is the approximate cost?

Previous owner has a panel box with circuit breakers controlling everything and no main shut-off. There was no grounding and bonding. An electrician said the installation is incorrect. On a budget and trying to do the right thing but not blow the bank.

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I am assuming here the circuit wires are three-wire insulated - fairly modern wires, with a ground wire in the wire bundles - probably type NM (commonly called Romex, which is actually a brandname) which is three insulated wires in a plastic sheathing (ground wire may be plastic or paper insulated), or BX or EMT which is two or three separate insulated wires (ground wire sometimes in paper insulation) inside spiral corrugated metal flex or rigid galvanized metal conduit. If NM is used, the ground wire is connected to outlets and fixtures and boxes at the destination ends, and to a ground bus in the breaker box, which is then connected to a main ground wire that leads to one or more outside 6-10 foot (depending on code age) ground rods driven into the ground. BX or metal conduit like EMT uses the conduit for grounding, grounding the metal boxes where it enters it, and grounded to the breaker box where the conduit is connected to it, then again the breaker box is grounded outside to one or more ground rods. May or may not have an internal ground wire depending on code year and local code requirements.

If your house is two-wire wired, then that is quite old but by code probably does not have to be upgraded as long as you are not rewiring the house or replacing more than half the wiring, but of course you would have much less (or almost none, with some systems) protection against short circuits and shocks. If you have cloth or asbestos insulated wiring that is very old (generally pre-60's) and is probably no safer than two wire wiring. Also, if you have 50's or 60's era aluminum circuit wiring (NOT including the main feed to the box, which is commonly aluminum and OK), that is a significant concern too. However, with a two wire or aluminum system you are talking typically at least several thousand $ to as much as $10,000 for a whole-house rewire job in a normal sized house.

He is right about no bonding and grounding being wrong, if the wiring was run three wire or in metal conduit. If you can live with the current box amperage capacity and number of circuits, adding bonding and grounding (assuming the box is not so old it does not have ground buses) would likely run about $200-400 in labor ASSUMING the wires are there and long enough and just folded back out of the way (not clipped), just were not connected. WAYYY more if ground wires were clipped off short - if that is the case, you commonly have to install several ground bus terminal and junction boxes to collect enough slack to connect each circuit to a ground bus, which is then connected to the main breaker box and the main ground bus or bonding wire. Sometimes takes 2 or 3 boxes due to wires coming in from several directions, as you have to put the box several feet closer to the direction where the wires are coming from to gain enough slack ground wire to connect with - sometimes you just bite the bullet and install several breaker boxes (at around $500-800 each installed) where there is enough wire length and connect the several breaker boxes to your main disconnect/master breaker box - which you do not have yet.

Now starts the fun part - since you are rewiring your breaker box, you may, by code, have to upgrade to GFCI/AFCI breakers in many jurisdictions - required by new code on new work. Sort of a gray area, and probably not required if only hooking up ground wires that should have been originally connected when installed. Your old box may be able to take GFCI/AFCI breakers, at about $25-100 for each breaker to upgrade depending on brand, unless you need a totally new box due to capacity overload or desire for extra slots or whatever, in which case the $500-800 number for a whole new box with breakers. In many cases a new breaker box is cheaper than buying all new breakers for an old out of production box, and also makes it easier and cheaper to find breakers in the future, which can run up to $200 each for very old models where the manufacturer went out of business. Also, if your current box does not meet minimum laod capacity for your house, by code you will have to upgrade anyway if you are rewiring the box.

So - simple case, maybe $300 range if just connecting ground wires up to bus bars, assuming there is enough slack - to $1-2,500 range if they clipped the grounds and you need to move the box, at higher end if need to install several boxes to get legal connections on all circuits. Note - IF your ground wires were clipped, SOME building departments will allow splicing of ground wires with UL listed non-reversible type butt connectors or positive-stop screw connectors without using a junction box like you have to for the live and neutral wires - in this case, they could be extended within the current jucntion box for maybe $300-400 range without having to move the box or put in new boxes. This would be worth checking on if this is the case - note these connectors are NOT reaqdily available for small wire, so would probably be special order - make sure your electrician does not start messing in teh box if he does not have the parts needed to finish the job. Normal crimp type butt connectors do NOT meet code for this.

Now, the bonding - a simple $75-150 range job (as part of the overall job) if you have bonding bus connection in the box and ready access to the outside (if ground rod is needed by code, as is almost universally the case) and ready access to your incoming copper water pipe (if your local code requires it be bonded to the ground also). Only about $50-75 range if you already have the ground rod and just need the ground cable installed from rod to box, or from rod to box and from box to water pipe. In a few jurisdictions electric water heaters, boilers, tankless heaters and gas pipes have to be bonded too - not a big thing, as the bond wire is typically run exposed and does not have to be concealed or in conduit.

Now, your incoming master disconnect - depends on whether your meter base already has a disconnect switch or not, and whether or not your local code allows a master breaker as a disconnect or also requires a manual "positive break" lever-type disconnect switch. This can run from about $200-350 installed for a simple main shutoff box (manual disconnect), to closer to $400-600 if you require a master service breaker (100A in your case) on your side of the meter or that plus a master disconnect switch.

I realize this was not a definite answer on cost, but a lot depends on your situation, and unfortunately that means knowing what your outside situation and code requirements are, and also taking the cover off your breaker box to see what is going on inside - not something you probably want to do yourself, or would be able to judge if the ground wires are long enough to connect to the ground buses.

If you have old wiring, or doubt about it because the ground were not hooked up (possible former do it yourself or handyman job ?), you might want to consider having the electrician pull covers and fixtures and check all of them for improper wiring too - it is quite possible the grounds were not connected at the destination ends either, which removes a lot of your protection against short circuits and shocks.

I would say this type of job takes several bids with a definitive scope of work, so you probably need to Search the List for several local electricians with good ratings and reviews, have them come out and scope out the work and tell you what is needed and tell them you will be looking for definitive bids after you understand what is really needed from several potential bidders, then after ALL have given their thoughts on what is needed, work up a written scope of work for them ALL to bid on, so all are bidding on the same thing.

Answered 6 years ago by LCD

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