wiring, mobile homes, and headaches

[Fuzzy]

My shop? is my old home, a 12x60 mobile home that I took the room
dividing walls out of, except bathroom and rear bed now office room.
As most of you may know these 'homes' have very screwy wiring in
one wire may connect all lites on the front left side etc,,,
At the moment my problem is using anything on the left side of
the old living room area and the table saw (bt3100-1)onleft or right
side as this causes the lights to dim!! would a larger circuit
breaker on the table saw line help? How about a larger main breaker
I know a dedicated line would help but I am back to the larger single
and breaker questions again!!

[LCHIEN]

Usually dimming lights when you turn on a large load means that the voltage drop in the wiring is pretty large. Which means that the
wire thickness is too small (the gage inverse so it means the gage no.is too big).

There's a small chance maybe you have a bad connection somewhere that causes a voltage loss when you load the line but somewhere before the branch where all the lights and equipment is there's too much loss.

Changing a circuit breaker to a larger size won't fix that!

[mpc]

Bad connections or too-skinny wire will cause voltage drops under load like you're seeing. Often wiring goes something like this:
Power company wires to main box.
Main box starts with main breakers, these then feed the "bus bars" inside the box. Other circuit breakers clip to these bus bars.
On each breaker there should be one output wire, this goes to outlets, devices, etc.
For wires to wall outlets, usually the input wires attach are screwed to the outlet (or inserted into little holes that grip the wire ends) and then another wire cable is attached to go to the next outlet... i.e. the outlets are daisy-chained to each other.

So what? First, identify ALL outlets on the circuit you're using for the saw. Easiest way: turn off the appropriate circuit breaker... then use a small table lamp to test all outlets one by one. Any that don't light the lamp are possibilities... make sure no wall switches affect the outlet you're using or, more directly, turn the breaker back ON and see if the light kicks ON. Once you've identified the whole string, plug your saw into the outlet CLOSEST to the circuit breaker box. If the saw runs better - and other lights don't fade as much - then you've proven it's the daisy-chaining from outlet to outlet that's causing your problems. Plug the saw into the next outlet and see if the problem gets worse or not... if you find it suddenly gets worse then THAT outlet, or the one before it, needs attention: probably dirty screw terminals/bad contacts.

If it's just as bad in the closest outlet though then it's somewhere in the stuff from the power company wires to the outlet: main breakers have poor contact, dirty bus bars, dirty regular breakers, poor wires, etc.

Of course follow all safety rules if you try to fix anything or open up outlets, the box, etc. Turn off the power INTO the box (have the power company or a licensed electrician remove the power meter) if you want to mess with the main breakers, bus bars, etc. For the regular breakers, turn off the main breakers first. For outlets, just turn off the breaker feeding that string. Or the main breakers if you're not sure. Always plug in a regular lamp to double-check outlets before assuming they are safe!

Increasing the amperage rating of a circuit breaker will NOT improve your situation... the circuit breaker is really just a switch that self turns-off when something causes too much current to flow. It won't "lower" the voltage like you're seeing... it's either fully ON or fully OFF, nothing in between. All increasing the circuit breaker amperage rating will do is cause your wiring to overheat and start a house fire if the circuit is over loaded... as if the circuit breaker was replaced by a wire.

mike c.

[mpc]

Oh, one other thing: wires going to/from outlets can be attached via screws or, on most modern outlets, just shoved into holes that "grip" the wires. Usually that grip method doesn't work as well; it's not as reliable as the screws after a few years.

Depending on the age of your mobile home you may find aluminum wire instead of copper. My house uses aluminum wire... common if it was built during a war of some sort when copper gets scarce. There's nothing wrong with aluminum wiring - it works just fine. I have no problems running a beefy compressor for example; at a friend's copper wired house the compressor stalled when restarting. The big thing to watch for: aluminum wires MUST NOT BE ATTACHED TO REGULAR OUTLETS DIRECTLY. The correct way is to wire-nut them to short copper wire "pigtails" and screw those to the outlets. The other correct way: buy the right kind of outlets... many say "AL-CU" on them; that means they're rated for both aluminum and copper wiring and can be used without those short pigtails.

If you have aluminum wire that's NOT connected properly you'll get a reaction at the outlet screws due to dissimilar metals - they'll eat each other, corroding away. That's a lousy connection and can cause symptoms like you're seeing. It also leads to a lot of heat... melting the outlet or worse starting a fire. Something to check if you see silver colored wire inside your circuit breaker box instead of copper wire.

mike c.

[Fuzzy]

wow,, thanks guys,, I am thinking along lchien's line,, some of the wires hop from breaker box to lite switch to outlet jump across the ceiling to another outlet etc,, very screwy.. I think I will run one
single line for the table saw and check all other tie points for loose contacts,, thanks all

[pierhogunn]

If you can afford it, this sounds like a job for a new panel, and some re-wiring w/in the home... might be safer then trying to get the older wire to behave...

Be Safe

Dan