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Q. We have no water from our well. The breaker on the well pump circuit in the main panel is not thrown, just buzzing. My pump is about 500 feet down, and is in a new well that is not quite 3 years old. I don't see fuses, but I think it has a relay that is about 6 years old on a pressurized tank, which has no pressure at the moment. The circuit breaker is circa 1980. The tank has no pressure and the circuit buzzes when switched on. What could cause this?A. The pump has a problem. The buzzing is the high current of the motor trying to start. The motor overload is probably tripping. That is the when the buzzing stops. It could be a problem with the pump or the starter circuit (relay, capacitor). The breaker is probably humming from the locked rotor current that the pump is drawing when it tries to start but can't. If you are comfortable with electricity at all, you can kill it out, take the old cap to a re-wind shop (or other electrical supply house) and get a match for around $5. Install the replacement and see if that works. It's much cheaper than calling the well man.
Q. I have the opportunity to run a direct circuit from the panel to a bath. 15 amps should be OK, right? I'll run first to the GFI, then to the switches, or what?
A. Don't even think about starting this project until you study the codes. There are a lot of bathroom codes. I recommend the $6 green paperback "Wiring Simplified," sold in the electrical aisle at most home improvement stores. Read it thoroughly.
No, a 15-amp circuit would violate code. Run a 20-amp circuit. Don't put anything outside the bathroom on the circuit. All receptacles must be GFCI protected, and at least one must be no more than 36" from the rim of each sink. Lights and fans in a bathroom normally do not require GFCI protection, but you can if you want. There's more. Read the book.
Q. I have a 100-amp blue line load center service box in my house I was looking to add a 30-40-amp breaker for 220 outlets in my garage. But as I add up the amperage of the existing breakers, it is already way over 100 amps. My question is, what is it I'm really looking at, and is it bad?
A. Adding up the breakers might be good addition practice, but it means nothing. A breaker provides protection against an overload. The breaker won't allow more than some number of amps to flow through it. It will, however, allow up to that amount of current. Most of the circuits in your house use far less than the maximum current, plus your loads are not all continuous and some are mutually exclusive.
For example, your water heater only runs when heating water. Most of the time, it turned off. The refrigerator and freezer only run when the air inside is too warm, most of the time they are off. (Okay, lights and defrost may run at other times, but you get the idea.) Your furnace and air conditioner don't run at the same time.
To properly size a panel to a house requires a load calculation. A load calculation takes into account square footage of the house, and makes allowances for electric heating, cooking, water heating, clothes drying, air conditioning, etc. There are also ways to determine how much power your house is actually using as well. These tests are more accurate than a load calculation, but also harder to run.
The main amperage rating is the max amperage the entire box can supply at a time. The rating of each individual breaker is the max safe amperage for that individual circuit. It is NOT an indication of how many amps that circuit is actually using. Unless several circuits are all being maxed out frequently at the same time, you likely will never trip that 100A main. Most general-purpose circuits are seldom maxed out. Now, run a vacuum on the same circuit of that microwave that is nuking your dinner and there's a good chance you'll trip that circuit breaker.
Keep in mind also, that 100A main is at 220V. Two 110V 20A circuits are equivalent to one 220V 20A circuit. So a 100A panel with ONLY 110V circuits can actually provide up to 200A worth of 110V juice. Now that is an oversimplification, and your panel almost certainly has a mix of 110V and 220V breakers, but you can see the point.
A load demand calculation (I believe that's the correct term) is the only way to actually determine whether you need more than a 100A service (Google that term to find out how to do one). If this 220V receptacle is just for an occasional use item, it's probably not going to have much effect on your home's overall load demand. Now, if your central head is on, the microwave is on, the turkey's in the oven, the range burners are in use, the vacuum's going, the electric dryer is running, the electric water heater is recovering, etc., and you start running a welder off this new circuit, you may manage to trip that main.
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