Upgrade of 100 Amp Electrical Fuse Box & Wiring
Giving you an accurate estimate can be difficult since I‚Äôve never seen your home, and it is hard to define ‚Äúnormal conditions‚Äù. I live about 30 miles north of Philadelphia, Pennsylvania. We completed an upgrade similar to what you are considering, about a year ago. The initial estimate was $750.00 for a simple 200-amp upgrade. When finished, the total cost was $1060.00. This included more work than just the replacement of the panel, some we did because we wanted to, and some of which you may need to do as well
First off, it sounds like you have fuses and not circuit breakers. If so, then there is really nothing salvageable from your current supply. Going to a 200-amp panel will no-doubt require a new meter box and meter. Your utility company should supply the meter free (ours did) but the box it hooks into is usually the responsibility of the homeowner. The price we paid included a new box.
You also need to find out if the supply lines from the street will handle 200 amps. In my experience, most older 100-amp homes will need to have these supply lines replaced with larger wire, and part of this can also be the responsibility of the homeowner. In our case, we had buried cable, and we would be responsible for the excavation and filling of the ditch, and the electric company would be responsible for the under-the-street drilling and running new cable to the house. We were lucky here, the original owner had some forethought, and the cable is in fact oversized. If you have overhead cables, then your cost may be significantly reduced if not eliminated.
Our home originally had a 100 amp fused main disconnect located in the garage, with a sub-panel of circuit breakers located in the stairwell in the middle of the house. The meters (we had/have two) were mounted on a retaining wall just outside the garage where the main disconnect was. There were also several small sub-panels mounted around the main disconnect, added for various reasons over the 45-year life of the house. For $1060, we had the following work done (it took 3 separate days to complete):
1. A new 200-amp, 40-space service panel was mounted in the garage, replacing the main disconnect and surrounding small add-on panels.
2. A 100-amp, 20-apace panel replacing the old sub-panel in the stairwell.
3. Two new meter boxes, as mentioned earlier. In case you were wondering what the second meter is for, the electric company allows us to hook up any 240-volt appliance to what they call off-peak service. They charge us a discounted rate, but there are certain times of the day/night when power to that service is shut off.
4. A 30-amp separate disconnect was installed next to the new main panel, which supplies the electric water heater, the only item we currently have for the off-peak service. The off-peak could conceivably be expanded up to 100 amps separate from the 200-amp main service, but that would probably require new service lines since both off-peak and regular service use the same ones.
Sorry for the long-winded reply, but there is more. If your home is 45 years old, the house wiring is probably 2-wire, non-grounded affair, unless it was upgraded since the house was built. If you have 2-prong outlets, then you probably have an ungrounded system, and your municipality/utility may not allow you to upgrade to 200-amp service unless the home wiring is upgraded as well. That can be pricey. You will need to verify what you have, as well as the local codes.
As I mentioned, my home is also 45 years old, but again, the original owner was ahead of his time, and my home was built completely grounded even though I had 2-prong outlets. I simply replaced the receptacles. But don‚Äôt be unnerved. Depending on your exact situation there are ways to work around the problem. I will spare you another long-winded description by simply having you talk to a local qualified electrician. You can always post again if you have more questions.
I always suggest, get more than one estimate, and check with your municipality for helpful advice and required permits. Good luck - TomR