How do you know if you need to upgrade just the fuse or breaker panel, of if the complete service entrance power needs to be increased?
Old electrical panels are not good, for many reasons. They will not have the capacity to keep up with today’s technology, plus they can cause nuisance tripping due to overloading and possibly start a fire. Whether you’re dealing with existing safety issues, renovations or resale, you should not ever settle for having a shortage of available power to your home.
The distribution of the available power will depend on the total available circuits and what is connected to them. Replacing a small fuse or breaker panel with a larger one that provides more circuits is sometimes all that is required to eliminate overloading problems in the home. It is however good to know what the available main power actually is.
Older installations may still have indoor metering and a separate main switch. If the cartridge type fuses are 60 amps or less, then the total power to your service is then limited to that amount. There were a few homes during the late 50’s and early 60’s in Winnipeg that were built with 70 amp services. By the 1970’s most homes were built to the new standard with 100 amp power.
With gas heated homes, it is not that often where the power requirements need to be more than 100 AMPS. Heavy drawing appliances or equipment such as a large hot tub or an extra electric stove in a granny suite or simply some auxiliary electric heaters can raise the total requirements to that of 200 amps to be safe.
To calculate the total draw or amps that are needed it is not necessary to add up all the breakers or fuses since the fact is that not all lites, appliances or equipment will be used at once. Even a 15 amp circuit by itself may never use more than an amp or two if there are only a few lites ever used. An electric water heater will cycle on and off automatically so it should be considered as being on with your calculation. A washer and dryer will likely be used at the same time but a stove may not. If the possibly is there then they should all be factored in.
A common range for example on a 40 amp circuit is only using around 27 amps or so with all of the elements and oven in use.
Most homeowners will not and should not be comfortable making this assessment since safety is involved. An experienced electrician will have the tools to test the actual draw at the service or at least make a professional suggestion for you.
When a service upgrade is required, Manitoba Hydro upon application by the homeowner or electrical contractor will attend and preview the service attachment location. This may end up being different that it is now for various clearance and code reasons.
Be sure and be safe!