On 1/15/2012 12:13 PM, DerbyDad03 wrote:
On this week's episode of Ask This Old House, an electrician was
replacing the service wire and panel in a house. There were code
problems within the panel (broken breakers, doubled up circuits, etc.)
There were at least 3 generations of wiring at the panel: BX cable,
cloth cover Romex and modern Romex. There was a rat's nest of wiring
in and around the panel.

He noted that he would normally mark all the wires before removing
them but since the existing labeling was wrong, he chose to simply cut
all of the wires and "figure it out afterwards".

As he was connecting the wires to the new breakers he used this simple
method to determine which wires to connect to which breakers:

"There are 3 sizes of wires. The smaller wires go to the 15A breakers,
the mid-size wires go to the 20A breakers and the largest wires go to
the 30A breaker."

Doesn't this seem to be an oversimplified, possibly dangerous, method?

Since it was obvious that whoever came before him violated codes by
doubling up breakers and who knows what else, isn't it dangerous to
assume that the correct wire sizes were used as the mess grew over the
years?

Maybe they were just saving air time by using that explanation, but it
seems to me that a lot more investigation should have been done as
opposed to simply letting the wire size determine the breaker size. To
even imply that the wire size is the determining factor seems
irresponsible on their part.


He did it exactly the way I normally would. The most important thing to
determine, are small gauge circuits that are 240 volt. Pretty much any
#10,8, 6 or larger gauge cables are going to be 240 volt circuits, but
you don't want to miswire a 15 or 20 amp circuit. As you disconnect the
wires from the breakers, you'd take notice of anything unusual about the
fusing and make a notation if necessary. Overall, you're pretty much
going to reconnect the conductors to the proper amperage and voltage of
the conductor size.