Replacing Knob and Tube Wiring

If the 20 amp cckts are for convenience outlets and the 15 amp runs are for lighting and / or convenience outlets and not a large consumer of power, then 30 feet is not a problem. I am assuming type NM cable and appropriate listed circuit breakers on each branch circuit.

Regards

I would agree. He's using it for his bedroom so his current draw should not be that great, unless he's got a really tricked out home theater with active feedback controls for his bed. Or he's trying to power a laser display on his bedroom wall with the switches. As for the 30 foot run I need forty feet just to get to my attic.

My home is over 135 years old. I replaced my knob and tube wherever possible. Unless it's buried in the walls I haven't seen anymore. The worst part is not being able to get the new wires in the same way the knob and tube was run originally. Many times you had to take the long way just to get to an overhead light on the first floor. My walls are all plaster and in great shape. I really do not wish to tear them down. The smallest trim is probably 6 inch walnut. On several occasions I took the trim off and ran the wiring behind the trim within the wall. The walls have 2x6's so drilling holes was no problem. Once the wires were pulled, I plastered the walls and put the trim back in place. You'd never know the work was even done. This may help in some places. Good Luck!

guest' national electrical code nec 3 watt per square foot for homes general lighting and devices, outlets , one 20 amp 120 volt would be 2400 watts divided by 3 = 800 feet square, so your 80 foot by 100 foot room minimum 1 20 amp circuit. the code is a base to work at, but you can raise that base with more circuits, outlets, & lights. perry

Since we don't know what country you're calling from, I'll use the Canadian Electrical Code for reference. For residential use such as you are proposing, the allowed drop in voltage from the panel to your outlet has to be no more than 3%. Table D3 of the CEC gives some typical lengths in metres for 1%. Just multiply by 3 for 3%:

__Amps ____ #14 ___ #12

==========================

___10_______ 6.1____ 9.8

___12.5______4.9____ 7.8

You should use #12 wire anyway, and your breakers will be 15 amps, so you're looking at something like 22 metres or 65 or so feet. Realistically, most houses run a lot more than that from the panel to the farthest receptacle, so I would not be concerned. At the worst case, if you draw the full load on all the receptacles, you'll see some voltage drop. It won't harm anything.

Grae

"I am running 4 -12/2 romex and 2 - 14/2 lines from the breaker box "

What about a ground wire???

If you have a 'breaker box' then you have a ground buss which means you Should have grounds run with your conductors.

You should probably hire this work out to a professional.Could prevent a fire.

The first <...problem...> is the country of installation, which has been withheld from the forum. The applicable country installation code needs to be followed.

The second <...problem...> is that the voltage of the installation has been withheld from the forum.

The third <...problem...> is that apart from <...the attic...> the method of installation has been withheld from the forum. The method introduces the question of heat dissipation from the cables, which affects sizing. The protocols for determining cable size are given in the applicable national standard.

The fourth <...problem ...> is that an omission of the testing record will invoke a measure of unpopularity with the building's fire insurance provider in the event of an emergency involving damage of loss of life.

The withholding of these pieces of information introduces WAGs into the answers and the possibility of a game of "20 Questions" will ensue.

If in doubt, consult a qualified local Electrician, who will design, install, test and certify the installation upon completion, giving peace of mind. It's a small price to pay.