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A Home Inspector Never Makes Assumptions

... or at least they shouldn't. Just last week I inspected a 4,200 sq. ft. house with a pool and spa and a 500 sq. ft. pool house going for $1.2 million. Wow, with such a nice and expensive house there must not have been any problems... right?

Wrong. The main panel had two serious issues. The first was that one of the 40-amp breakers (circled below)had undersized wires. That basically means that the wire could overheat and scorch before the breaker even tripped.

The second issue was the same as the first, but for for the main breaker! (pointed to below) The main breaker was 225-amps, which requires 3/0 AWG copper wiring (3/0 is pronounced 3-not). However the wires were 1/0 AWG copper, suitable for 175-amps max.

undersized wires

Undersized Wire

You can see the 1/0 AWG writing on the wire is circled. The real kicker is that this house was just recently inspected!

I hope this gives you a little more information about a home inspection and why it is worth it to invest in a professional to do the job. Be safe out there.

Posted by Joseph Lang - Southern California Home Inspector on 02/19/2008 12:59 PM

Comments (10)

electrical panels, electrical wire sizing, rancho cucamonga home inspections, upland home inspections, chino hills home inspections

10 Comments on A Home Inspector Never Makes Assumptions

FEB

2008

Great post, Joseph.

It is always a good idea to get a home inspection on every house.

Have a great day!

FEB

2008

Richard, thanks for stopping by. Take care.

Joseph - Would this have been even MORE of an issue had there been 3/0 AWG to a 175 amp as opposed to 1/0 AWG to a 225 amp ? It seems to me that it was undersized ... what are the risks there? It seems that being the reverse would be a much larger concern?

Derek, electrical wires all have a certain thickness. The thicker the wire, the more amperage it can handle. 3/0 AWG on 175-amp breaker would not be a problem because the wires could handle up to 225-amps, that's fine. However, with undersized wires, the wires could potentially overheat, melt, scorch and cause a fire before the breaker trips. Did I explain that okay?

Maybe you were thinking of smaller breakers where the smaller the number AWG the more amperage it can handle. But when you get over 1/0, the larger the number the more amperage it can handle.

Joseph - Yep, that makes sense to me. Thanks for clarifying and for the interesting, informative posts that you diligently make...

Derek, you're welcome.

FEB

2008

Good post, nice pictures and editing.

Every old home that has been built wrong, including mis-wiring, started out as new. The more expensive the house usually means more expensive mistakes.

Another common wiring problem I find is oversizing of breakers for air conditioning compressors, and GFI problems @ spas.

I agree with your explanation about wire sizing. You stated it very clearly.

Steve, thanks. I also agree about the common problems with A/C and pools/spas.

SEP

2008

Good catch, would you have still been able to call this out without the wire sizing being printed on the wire?

AUG

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