Whenever I see panel boxes where breakers have been added, or changed, I have to think that altering (or adding to) the electrical panel box is serious business.
This is a house with a basement "finished" without a permit. I know this because of all the things found that are not to code (and I am not the code inspector) or professionally. Always basements without permits are "finished" by people who THINK they know what they are doing.
The cliche applies: we don't know what we don't know.
I am especially bothered when breakers are installed but they are not serviced by properly-sized cables.
Current flowing through conductors dissipates heat, and the greater the current, the greater the heat. Too much current and things overheat. Sometimes things overheat dramatically and fire happens.
Over-current protection in homes comes in the form of circuit breakers (or fuses in older homes). They are designed to LIMIT the amount of current to a safe level. If the current exceeds that level, the breaker or fuse will turn off the circuit - they will trip.
But what if the over-current protection device is inappropriately rated so they it allows more current to flow than the connected wires are able to safely conduct?
THAT IS A BIG PROBLEM!
It's a problem because, of course, it is incorrect. But it's also a problem because it indicates unprofessional or uncaring work.
IF WHAT I CAN SEE IS SO BOTHERSOME, WHAT ABOUT WHAT I CANNOT SEE?
What might be going on inside the walls of, say, a "finished" basement, not done with a permit?
Notice the black and red cables in the photo. They each service 30amp circuit breakers. Notice how fat they are?
Now look at the two lowest breakers on the left. They are also 30amp breakers. See the size of the cables servicing them? Hard to tell, but they look to be 15amp cables!
Under the panel box is a receptacle labeled, with a magic marker, "220 Only." Into it is plugged a large 220 volt air compressor.
It might be that used to be a regular 15amp receptacle that used to service the garage. Did somebody pump it up with 30amp breakers, so a 220 air compressor could be used?
The 20amp breaker above them is serviced with the same size cable. And it is also new. It may service the basement. It's so labeled, but I don't trust that.
It is licensed electrician time.
The amount of current that can safely flow is determined by many things:
1. The type of conductor - copper or aluminum.
2. It gauge (thickness) - fatter cables carry more current.
3. The insulation temperature rating.
4. The ambient temperature. This is important. A cable passing through the attic can carry current than it could in cooler areas. So it must be sized differently.
5. Whether the cable passes through thermal insulation that might allow heat to accumulate. This dissipation of heat is why cables are not bundled.
Important: in 2005 the NEC tightened rules regarding ambient heat and required that cables be rated for 90 degrees Centigrade (194 Fahrenheit) instead of the older 60C (which is 140F). MOST OLDER INSTALLATIONS DID NOT USE CABLES RATED FOR 90C, AND MAY BE LESS SAFE.
This is why installing newer appliances or light fixtures in older homes with older wiring may require an entirely new wiring job. Many instruction manuals so specify, but hey, who reads instructions?
My recommendation: it is essential that a panel box be investigated, particularly when a homeowner or other non-professional has been in there doing their "work." Too many things can go wrong and a buyer will inherit all that. Certainly in these cases an electrician needs to evaluate and rectify any improper goings on.
Note: this inspection was with Cindy Jones of ActiveRain. The buyer was not present. At one point I did not trust the drain for the "finished" bathroom in the "finished" basement. I thought the flushed toilet water might pass through the shower drain and introduce itself into the air. So I had Cindy flush the toilet while I smelled the shower drain and watched the water in the trap. While the fabled "refrigerator repairman butt" was not displayed, I apologize to her for the view and to you for the image you now have in your head...
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