United States here. I have a 150 amp main service panel coming into my home and after spending some time going through the house with a voltage pen/tester, I now have a perfect understanding of which outlets, switches and appliances are powered by which breakers (and yes there were a lot of discrepancies between what I found and what was written on the breaker panel labels...).
I found that several 15- and 20-amp 120VAC breakers seemed to be burdened with a disproportionate amount of the electrical load around my house. Several of these poor suckers seem to be providing branch circuits for a little too many outlets and lightswitches for my (uninformed) liking. Similarly there are several breakers/branch circuits that only provide power to a single (lone!) outlet.
I am wondering if anyone can explain to me the process of calculating whether or not a particular branch circuit (and the breaker running gatekeeper to it) is over- or under-utilized; over- or under-"powered" so to speak.
Obviously, different things that plug into the outlets may draw different amounts of watts, current, voltage, etc. If a particular branch has 100 outlets that are part of it, and nothing is plugged into + running from any of them, I'm sure the breaker won't trip and all will be well. But if you plug 100 washing machines into each of those 100 outlets and run all of them at the same time, something tells me that the breaker will trip.
So to me there is the idea of "average, reasonable" load on the circuit as well as maximal load. The average reasonable load might be the average amount of load/burden on the circuit at any given point of time. Maximum is, well, the maximum load the circuit can handle without tripping the breaker.
So I guess I'm looking to understand this: given a particular breaker (amps and voltage; say, 120VAC at 20-amps), how could I tell how many outlets, lightswitches and other loads (ventilation hoods, bathroom fans, dishwashers, etc.) that breaker/circuit can handle, so that I can "size" each of my branches correctly and determine whether they are over- or under-utilized.
Hint: we've lived in this house for 12 years and haven't had any housefires, so I'm not too concerned about the seemingly-overloaded branch circuits. This question is more about the theoretical calculation of branch circuits and what loads they can or cannot carry. Thanks in advance!