This document discusses when an electrical panel upgrade may be needed during home renovations. It notes that the electrical panel can provide insight into the home's wiring and that new circuits may require an expanded or replacement panel. A demand load calculation is conducted to determine if the existing electrical service can support added appliances. If demand exceeds the main breaker rating, options like a service change or switching loads must be considered within the renovation budget and for safety according to electrical codes. Safety of the homeowner is the top priority in making recommendations.

1.
When I am Renovating, Do I need to Increase the Size of my Electrical Panel?
This is a question that is sometimes asked by clients when we assess renovation projects but a
question we always ask ourselves. As a matter of fact, looking at the electrical panel is usually
where we begin.
The electrical panel usually gives us an idea of the general health of the wiring in the home. If
we see sloppy wiring, code infractions and safety concerns, they need to be rectified and
included in the client’s renovation budget. Beyond that, we estimate the number of new
circuits required by the renovations and, if there are inadequate breaker spaces in the existing
panel, it is usually a simple matter of adding an adjacent subpanel. In rare cases we will
replace the existing panel with a larger one. This is usually done with older panels which are
showing signs of degradation or have inadequate grounding hardware.
We also look at your electrical service, which is the cable running to your home from the
power company to your meter, the meter box itself, and the wiring from the meter to the
panel. If we feel that your electrical service may be undersized, we conduct a Demand Load
Calculation according to the Canadian Electrical Code. This calculation includes a factor for
the finished area of your home plus additional considerations for electrical loads over a
certain wattage. Some of the items which may increase the draw on your electrical system are
double wall ovens, convection cook tops, electric heating, electric floor warming, electric snow
melting, air conditioning, jacuzzis and hot tubs.
The Demand Load Calculation results in a figure in amps which we compare to the current
rating of the main breaker in your panel. If the calculated demand is less than the main
breaker rating, no upgrades are required. If the calculation exceeds your system rating,
however, some decisions need to be made and they usually relate to cost.
A service change with overhead supply lines is relatively simple and inexpensive. It usually
involves changing the existing meter box and conduit, installing heavier conductors, installing
a new panel and arranging with the power company to provide new supply lines. An
underground supply, however, can involve trenching back to the utility pole or transformer
and can be much more expensive.
Once a cost for the service change is estimated, the client decides how that figure works
within the renovation budget. Sometimes a change from electric to gas appliances can
eliminate the need for a service change. In other cases, we can provide switching of loads
from one to another, either manual or automatic, which ensures that two heavy loads cannot
operate at the same time. This will bring us within tolerance.
As a contrator, we don’t play games with Demand Load Calculations. These are hard
calculations that concern client safety and are mandated by the electrical code. We have lost
jobs on this issue but we don’t say, “I think you can get away with it”. An electrical inspector
once asked me, “If you wouldn’t do it in your own home, why would you do it in someone
else’s?”. That has always stuck with me and it is a philosophy we live by.
Neil Edwards,
Alberta Master Electrician