Wayne Ray wrote in a message to Mark Dudley:
 >A good way to see how things are running in a current house is.. Use the
 >normal items for a while, then, check your breakers, run your fingers over
 >them, if any of them are warm, you know they are pulling a nice load, if
 >they are TOO warm, or so hot you can't hold your finger on them, you are
 >pulling too much and need to reduce the load. Don't installed a bigger
 >breaker, without ensuring that the wiring can handle the extra load the
 >bigger breaker will allow.
 WR> Correct. Circuit breakers, and fuses for that matter, are 
 WR> solely intended for the protection of the wiring, and should be 
 WR> sized for the wire used. 
To the contrary,  wire isn't in and of itself damaged by running somewhat 
warm,  or even a little hot (though the insulation on that wire is another 
matter ).
It's the stuff *around* that wiring,  wood framing and other such stuff,  
that has a problem with it.  Generally most house wiring just isn't set up to 
deal with wires that get too hot.
Of course,  if it's doing that,  the results at the "load" are going to be 
inefficient as well since there's going to be a lot of voltage drop,  but 
that's another issue...
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