I hear "So what's the big deal about ...." a lot more than I would like. One particular area I hear this about is an oversized breaker in electrical service panels.
This question usually pops up after I inform my client that they have an oversized breaker for a major appliance or A/C unit. More times than not, it is from a building superintendent, builder or irate seller.
The "Big Deal" is that an oversized breaker is not only dangerous, but can also cost you money down the road.
Think of breakers like a protective valve. When a certain amount of electricity builds up in the wire running to the breaker, that breaker trips to prevent damage or a dangerous overheating situation from occuring.
I was inspecting a home in The Woodlands and saw a great example of an oversized breaker and undersized wire for an A/C unit. When I opened the panel I saw the A/C wire that connected to the breaker had about 3" of the jacket melted off. After further investigation I learned that the seller had installed this new high efficiency unit a couple of years back. Apparently the HVAC contractor wasn't paying too much attention or just plain ignored the larger breaker that used to serve the old unit. The new high efficiency unit called for a 25-amp maximum breaker, however, a 50-amp breaker was being used at the time of the inspection for this A/C unit. (Note: New high efficiency A/C units will usually call for a lot lower breaker size than the same sized unit did only a few years ago due to their more efficient use of electricity, this is why a new breaker should be installed when your new unit is put in)
It was obvious they had had some problems with either the old unit melting the wire or the new unit. Not only was this a cause for concern at the time, but also if a service tech had ever come out to perform warranty work on the unit and had discovered the oversized breaker he could have, and probably would have, voided the warranty on this newer unit.
Oversized breakers are one of the leading reasons why warranties are voided on new appliances and it's not just A/C units either. Ovens, electric ranges, dryers and more can have their warranties voided if a larger breaker exist than what the manufacturer calls for. I often see appliances 5-amps over. While this doesn't really affect the appliance, it can void the warranty on a new appliance so I will bring this to my clients' attention.
Electrical wires of a certain size can only have so much electricity pass through them before heat starts to build up. That is why each wire size has a maximum breaker size that can be used. When the elecical current builds up to a certain point, the breaker will trip, thus protecting the wire and appliance if they are of the proper size. Breakers larger than what the wire size can handle can allow heat to build up in your wiring because they will not trip when they are suppose to and that can lead to the jacket melting and possibly catching fire or catching the surrounding material on fire. Larger breakers than what the manufacturer calls for can refuse to trip in the event that something goes wrong with the appliance and cause damage to the appliance or worse, cause a fire.
A few month's ago I was inspecting this new home still under construction for one of my clients. As I was checking out the service panel and checking the different breakers to make sure they were labeled correctly and that they went where they were suppose to be, I noticed the breakers for the A/C were grossly over-breakered. I reported that the A/C manuacturer called for a 30-amp breaker on the downstairs unit and a 20-amp on the upstairs unit and that a 50-amp breaker and 40-amp breaker was installed instead and that these needed reduced to the proper breaker size. Several weeks later I was back at this home to do a final inspection just before the walkthrough to make sure everthing I had marked in my previous report had been fixed or repaired. When I opened the service panel front, the same oversized breakers were still there! I told my client about this and he said
"Oh yeah, the builder called and explained the reason for those larger breakers. After he told me why they were there I told him they would be okay."
"Exactly what did he tell you" I asked."
"That those larger breakers were there so I would have more power to my A/C units in the summer when I would need it more." he said.
You could have knocked me over with a feather!
I really thought for a second my client had been trying to pull my leg, but when I saw that he was being serious I calmly explained to him why it was important for those breakers to be reduced and why it had nothing at all to do with "power". I really wanted to further explain to him that the art of blowing smoke up a certain part of the anatomy had almost been successfully performed on him by this Builder, but I refrained!
Now I hope your begining to understand "What the Big Deal is" when it comes to oversized breakers and why they need to be corrected. Remember, when in doubt, call an electrician to check out your homes electrical system. It isn't worth the risk to you or your home to be living under these circumstances.