Our house os about 100 years old and I think still has the original wiring. It's wired entirely in 12 gauge wire and it's all in metal tubing--not sure what to call it. We still have fuses, not breakers. The wiring coming OUT of the box is still 220, and then it splits into 120 at junctions boxes. The way the fuses are, and I hope I'm explaing this right--I'm no electrician!-- is this: there are two fuses for every circuit, the black wire goes to one, and the white wire goes to the second. Someone told me they used do wiring like that on boats and ships a long time ago, if that helps explain.They are all 30 amp fuses, which I know is rather high. Considering the house has been here 100 years without burning down, and we've been here 3 years without any problem, so I'm guessing it's probably fine, but here is my concern. With 30 amp fuses, is it possible the wire could catch fire before the fuse blew? Or does the 12 gauge wire and the way its wired make higher amp fuses ok?
2007-02-03 01:33:53 · 6 answers · asked by lillith6662000 3 in Home & Garden ➔ Maintenance & Repairs
I am an electrician and that is very interesting, I could ask my father who has been in the business for 50 years, me, 25. All the above answers are good ones, weakest link etc. The fact that all you wires are in "conduit" or "e.m.t" (electrical metallic tubing) is a very good thing if it runs through the house all the way to the devices (plugs etc) because it gives you a GREAT ground which is very safe and if the junction boxes are also steel or metal you are very safe because it ia less likely for "fire" to escape from there. One thing you might do is occasionally feel the conduit with your hand and see if it is every "warm to the touch" which might tell you it is drawing much electric throught it, warm is somewhat O.K but getting closer to hot is NOT. Good luck, I think your O.K but I agree with the other dudes above, switch to 20 AMP fuses if you want to feel safer.
2007-02-03 02:00:37 · answer #1 · answered by Zippy 2 · 2⤊ 1⤋
You do have a problem when it comes to the fuses at 30 amp, on a wire that is only rated for 20 amp circuits. This is why you haven't blown any fuses. In the chain of the circuit, you want the breaker or fuse to be the weakest link in that chain. At this point, your wire is weaker. This means that you wire will burn before the fuse blows.
Since I'm not there to look at it personally, I HIGHLT sugest that you get an electrician there to look at it. Till then, limit the load that you put on these circuits. I hope this helps.
2007-02-03 09:45:02 · answer #2 · answered by D.Y. 2 · 2⤊ 0⤋
In regards to the amperage rating of your fuses- This rating in the code is for the thermal protection of the wires in that circuit. A wire can carry ALOT of current (amps) which produces heat. The rating of the wire is the safe amount of current that a wire can carry without damaging the insulation (by overheating) of the wire. For example you can put a 50A fuse on a 12awg wire and it will work without you noticing a problem, but when that circuit pulls more than safe amounts of current (20A for 12awg) the wire will heat and break down the insulation and viola FIRE!
The tubing in which you refer is called conduit, and is a good thing you have it. Conduit acts as another ground path as well as protection of the circuitry, and structure.
There should only be one fuse per 120V curcuit, the neutral (white) is the safe path to ground. If a fure where to be on the neutral and that fuse blew then everything on that curcuit would be live with nothing to continue the curcuit to ground but you..ZAP!
In regards to your question of concern, i can not call myself an electrician and then say 30A is ok on a #12 wire. It is forbidden in the code to exceed 20A on #12 awg copper and 15A on #12 aluminum. But if you have copper wire then **wink wink**, if it is aluminum then REPLACE it ASAP seriously.
2007-02-03 10:26:28 · answer #3 · answered by NubbY 4 · 2⤊ 0⤋
Depending on how long you've had 30 amp fuses on your 20 amp wires, you may have already permanently damaged the wires by overheating them. This makes them brittle, they loose their elasticity and cannot handle (safely) the amount of load (20 amp) they were intended to.
To begin with, get rid of the fuse boxes and install a breaker panel. If any wire is found to be damaged, then replace it. Also have the electrician install arc fault breakers on other circuits he / she may be concerned with.
You can't change all the wiring in your house, but you need to be extra cautious.
Take safety precautions by having the appropriate amount of smoke & carbon monoxide detectors installed in your home.
Good luck.
2007-02-03 09:57:56 · answer #4 · answered by TheElectrician 4 · 2⤊ 0⤋
12 guage is rated at 20 amps. usualy you dont want to have larger fuses those places, such as appliances, your dryer and electric water heater are more of the 30amp appliances. I would change the 110volt fuses to 15 or 20 amp fuses just to be safer. the higher the amp rate on the fuse, the larger the spark when something goes wrong. It would pay off in the long run to have an electrician to just look over it and give some advise. Be safe
2007-02-03 09:40:33 · answer #5 · answered by no_strings_72756 2 · 2⤊ 0⤋
US too
2007-02-03 09:37:34 · answer #6 · answered by Anonymous · 0⤊ 1⤋