Electricians: I have to ask a question.

Factual Questions
1

I have the pleasure of being able to upgrade the wiring in my house. Honestly, it is a pleasure. It’s a true labor of love. The reason I am upgrading the wiring in my house is because our house was built in 1895. The wiring inside the house is a mishmash of knob and tube, cheap 1950s cloth covered ungrounded wire, and more current three conductor PVC wire installed sometime in the 1970s when the house was divided up into apartments.

We bought the house at a good price, in a dilapildated state, in an area that is undergoing some gentrification. Since the slate roof was good, the foundation was good, and all of the pipes were good, we figured we can fix everything in between. It has pretty much panned out that way so far. Since most of the plaster is degraded anyway, and we have to upgrade the electricity, we have the absolute freedom to make this house exactly the way we want it. It’s awesome.

Before we bought the house, the inspector was adamant that we atleast upgrade the fuse box in the basement to a modern circuit breaker box. We hired an electrician to do that. He got a new meter put on the outside of the house, ran brand new conduit into the circuit breaker box, and filled it full of brand new circuit breakers.

One interesting bonus was that, the electrician ordered a 150 amp box, but was sent by mistake a 200 amp box. He let us know of the windfall, and installed it anyways, hooking up all of the old wires into the new box. I know, :smack:. The check has already cleared.

So now I’m going around the house with a sledgehammer and smashing holes in the walls. Collateral damage isn’t an issue here. You barely notice any new holes in the walls. Through these holes I’m tracing the old wiring - it is a mess. It is these same holes that I’m feeding the new wiring through, as I’m removing the old wiring, at the same time. I’m also running Cat5 at the same time. I have BIG plans.

I’m doing everything safely and by the book. I’m not cutting any corners to save a buck. Everything I’m using is the best that I can buy. EVERYTHING will be properly grounded. I assure you. For christ’s sake, my cat is grounded properly.

I have a plan. Each room I will treat as a separate “pod”. All of the wiring for each room will converge into separate junction boxes above the outside hallway ceiling (which has already been removed), on all three floors. Then, each individual junction box will connect to the other junction boxes and then head down to the circuit breaker box. This way I can systematically tackle each room as a digestible chunk, and if there is a problem, I can isolate it to a particular room. The first room is already done.

So now my questions:

  1. Besides the double breakers in the breaker box (30 amp, IIRC?), all of the other breakers are evenly divided between 15 and 20 amps, according to the stickers right on the breakers. What would be the logic for the electrician to do this?

  2. Assuming that in each outlet there will be plugged some sort of light duty appliance: computer, lamp, alarm clock; and atleast one light on a light switch per room, what would you consider to be excessive for each circuit breaker?

  3. I’m into uniformity. Since we ended up receiving a 200 amp circuit breaker box, more than we could ever use, we have rows and rows of circuit breakers - more than one for each room in the house. In this situation, would you consider putting each room on its own circuit breaker?

  4. I’m also into aesthetics. Once I’m done, I want to pretty much eliminate any excessive wires on the floor. Is there a device that I can add to a line that would act the same as a surge protector that one would plug their computer into, that would automatically reset itself after a surge? I don’t believe GFCI would work in this situation.

2

For #4, you can get a surge protector wall plate, like this or this.

3

  1. Circuit breakers are chosen based on the gauge of wiring used, and the length of the wire runs. Wire gauge is selected based on the estimated load. Thus, a bedroom that is only expected to have a couple lamps, a TV and a clock radio would need only a 15-amp breaker and 16 gauge wire, whereas a kitchen, with a refrigerator, a microwave oven and other appliances wold probably be on a 30-amp breaker and 12-guage wire.

  2. See above.

  3. Sure, plus separate breakers for each large appliance, like an electric stove, or the clothes dryer.

  4. There are multiple-outlet surge suppressors which plug directly into the outlet. There is no extension cord.

4

I am not an electrician, but…

Wouldn’t you run 14 AWG wire for a 15 amp circuit?

Wouldn’t you run 10 AWG wire for a 30 amp circuit?

5

You might be right. I haven’t unpacked all my books yet, so I’m going from (fuzzy) memory.

6

The kitchen would likely be on several 20 Amp circuits (not 30), except for the stove which is something like 50 Amps. And I’m pretty sure QED meant 14 gauge wire for the 15 Amp service. Although there’s no harm (and little extra expense) in just using 12 gauge throughout. (The only possible problem with using just 12 gauge is that you may have to use larger outlet boxes to conform with code if you have many wires in the box.

If you’re wiring the house yourself, you should invest in a home-wiring book that summarizes the code requirements. They’re generally common sense – dedicated 20 Amp circuits for the kitchen counters and the beefier appliances, GFCI near water, outlets every X feet of wall to eliminate the need for extension cords, and so on. Anytime you run a wire through a stud, make sure you cover the stud with a nailing plate so that you don’t put a drywall screw through it later.

One problem with putting each room on a separate circuit breaker is that if you blow a breaker, all the lights in that room will go out. It’s also a bit overkill.

7

search google for ‘electrical faq’ or ‘home electrial faq.’ The home electrical newsgroup faq is better than many books you could buy.

15amp/14guage wire is easier to fish into tight spots because it’s more flexible and thinner.

If you put each room on a seperate breaker it would be very easy for someone to cut the house into apartments again. The electric would already be divided and only need to be put in seperate boxes.

8

IIRC, 16 gauge hasn’t been manufactured for branch distribution since before WWII-it was for 7.5A circuits when houses were still supplied with gas lighting and only had a 30A 120VAC 2 wire drop.

14AWG=15A, 12AWG=20A, 10AWG=30A. These are not hard and fast rules, as they have numerous variables, and subtle differences occur with every reissue of the National Electrical Code, that document being revised every three years.

The 200A panelboard was better-the guys at the supply houses tell me that no manufacturer produces a 150A panel-it’s a 200A panel with a 150A main installed.

You mentioned that the dwelling had been previously divided into apartments. Is there any possibility that the dwelling will be divided into separate living spaces, either by you, or after a future sale? If so, the panelboard should be located in a common space, as the NEC requires ready access to overcurrent protection (fuses or circuit breakers) for a dwelling space by all occupants thereof.

Personally, I like to separate lighting and appliance loads. A kitchen must be supplied with not less than (2) 20A GFCI protected circuits. For bedrooms, I’ll take the fixed lighting branch on the ceiling or switched receptacle (you must have one or the other) and tie several of them together on one branch, separate from ordinary convenience receptacles, such that if an appliance causes a fault, at least you’re not in the dark, too.

If you’d really like to make everything meet the latest code, you’ll need to install AFCI breakers for bedroom branch circuits. Arc fault circuit interrupters look for the arc signature of a fault in a broken or damaged wire, those conditions often being a precursor to fire.

Please-if you don’t have a strong electrical background, buy a good textbook or two, or talk to a tradesman buddy who is up on the latest code variations.

I’ve never gone to a house where the occupants drowned from plumbing mistakes, but have extinguished fires caused by noncompliant electrical work. Be safe.

9

Why is this a problem? You’re up an running, and you can replace circuits whenever you get around to it. If you replace a knob & tube circuit (which has 2 separate wire coming into the panel) you’ll need to install a goof plug on the extra hole in the panel.

Ah, you’re a destruction worker. That’s fun.

Yourealize that it is OK to leave dead wire in the walls, right? You don’t have to rip out everything (although it can be convenient, sometimes). Also, it’s a good idea to keep low voltage (cat5, rg6, etc) separate from high voltage (120VAC, etc). If they are parallel, keep them one stud bay apart. It is OK if they cross, but try to make them cross perpendicular.

You do know that junction boxes must be accessible, right? They can’t be hidden behind drywall. Also, inspectors hate junction boxes - too many is a sign of an amateur/shoddy job.

Why not just run from the panel to the closest outlet in a room, then string wire from there to other outlets in the room. I agree with a previous poster - keep the outlets and the lights on separate circuits. Perhaps have 1 circuit per room for outlets, but share a circuit for lights for 2 or 3 rooms.

Adding to what others wrote, you must also have a dedicated GFCI circuit for each bathroom. It’s a good idea to make the lights in the bathroom GFCI, too, in case some bozo tries to change a lightbulb while standing in a tub full of water.

As others wrote, wire gauge. knob and tube was often 14 gauge.

Add up the expected loads, and size accordingly. Look on the products for the numbers, in eaither watts (divide by 120) or amps, but otherwise assume a lamp is approximate 1 amp (100 watt bulb is 0.83 amps), a computer is 1 amp, and a small appliance that doesn’t produce a lot of heat (like an alarm clock) is 0.1 amps. Small appliances that do produce a lot of heat (toasters, hair dryers, little heaters, etc), figure about 10 amps.

There’s no problem with a too-big box. It gives you room “just in case”. I wouldn’t waste the space in the box, however 1 circuit per room is a good deal if you can do it.

Surge protectors, like those on power bars, don’t do much anyway. Better to go for a whole house system. A surge suppressor is only as good as its ground!

10

Go for the overkill! It’s cheap and easy to do when building a new house (which is basically what he’s doing here), but is much tougher & more expensive later on. Maybe even 2 circuits for each room, if you want – it only costs you one more run back to the circuit box, but it sure makes it easy to add on later.

But I would agree with others – separate lighting & power outlets. Then you can still have lights after something blows the outlet circuit.

I’d also consider going for 20 amp/12 gauge wires in all the circuits, even if it means replacing the 15 amp breakers with 20 amp ones. Yes, 12 gauge wire is a harder to fish through walls than 14 gauge, but that hardly applies here, where you are gutting the walls anyway. It’s much easier to work with all the same size wires & breakers.

And put in way more outlets (on separate circuits) in kitchens & bathrooms than you think you will ever need – enough that your family makes fun of you. Years later, they will be useful. (But don’t expect your family to ever apologize.) And nowdays, the same applies to home offices. Often, there will be a UPS for the main components. But you should have a separate circuit for that, and then plenty of other outlets for all the other office equipment.

Outdoor outlets (inside weatherproof covers) are really useful. Make sure you have one in both the front & back yards, and on the garage. In cold-weather states, a garage outlet controlled by a switch or timer inside the house (for engine heaters) is something you will appreciate every day the temp’s below zero!

One other thing – label your circuits! Most homes are terrible at this, and that’s really annoying! It’s real easy to do this when you are wiring up the place, and you’ll really appreciate this whenever you go to change the wiring. And when you’re fumbling in the dark trying to find a blown breaker.

Best way I’ve found for this is to get from an office supply store 1 or 2 plastic page protectors (pocket type) and tape that to the door of the breaker box. Then put a full size sheet of paper in that with the markings on it. Make up a file on your word processing software (use big fonts) and save it there. Update this paper by hand every time you make a change (do it the same time you connect a new circuit into the box), and then periodically take that to the word processor to update it and print out a nice neat new copy. Also use permanant room names, like “NorthWest bedroom”, instead of “Johnny’s room”. Or use both! And you have a whole sheet of paper, so include details in your list. Like: “Garage west wall outlets, outdoor driveway spotlight, garage door opener, air compressor”. It only takes a little bit of time when you’re wiring up the place; much harder to do later on.

Finally, be careful – sloppy wiring causes a whole lot of house fires. Might be worthwhile to do just one room, and then have an electrician friend look it over and tell you if you did it right. Or maybe pay somebody who’s not a friend to do this. It’s much better to find out about mistakes that you have to re-do after the first room, rather than when the whole house is done.

11

I agree. I never use 14 AWG, since in the future I might need extra capacity on a 15 amp circuit. (If I use 12 AWG wire for a 15 amp circuit, I simply need to swap out the breaker and receptacles to convert it to a 20 amp circuit. If I used 14 AWG wire for a 15 amp circuit I’m SOL.)

12

Excellent information everyone! I really appreciate it. I do have several books on electricity that I bounce back and forth between. I will pick up an official electricity code book before I continue.

It looks like I have to do some minor tweaks, per the suggestions above, but I was atleast on the right track.

13

Unless someone has already mention… Also be sure to use GFCI breakers for outside and garage outlets.

14

Some additional thoughts: Since this is an upgrade of an older system, you’ll want to ensure proper grounding and bonding.

If you have your own well, then bond the metallic piping within 5 feet of where it starts, usually close to the well pressure tank and control switch. If you have municipal water, do the same, observing the 5 foot rule. Connect the driven ground rod to the ground/neutral bus. If you have no driven ground, install one. If you have gas, bond that piping to the cold water line. The idea here is to electrically equalize the potential of anything connected to an appliance that uses electricity, such that a fault will cause the appropriate breaker to open the circuit.

When you’re done, have an independent electrical underwriter inspect and place a seal on the panelboard. If you fail to do so, and there was a problem, your insurance company could deny responsibility.

If you’re going to purchase a code related text, consider the National Electrical Code Handbook. It contains the entire text of the code, with brief explanations below some of the sections that cause confusion. A few dollars more, but worth it IMHO for non-trades persons.