As you mentioned there are very few loads that would run “continuously”, EVSE’s are probably one of the few heavy loads that would meet this criteria. (unless someone was running a HP mini-split during a 100 year artic blast) 🙂 The 120 volt loads are typically minimal and short term, and only affect the phase they are connected to.

With the efficiency increases in appliances and home construction the common 200 amp services are more than adequate for most homeowners. EV’s may be the outlier to electrical needs.
As you mentioned there are circuit splitters for EVSE’s , also people with multiple EV’s can use smart EVSE’s. They will throttle the load for multiple EV’s charging at the same time so they will limit the amperage to only one circuit.

Some of mine are split and others aren’t. The last time an electrician came over, I was told it would not work to have any more wires running through the circular hole under the 200 amp panel because it was already too tight.

I agree with Alexander. I had problems with a range hood not working at all and some GFCI outlets not working. I went into the panel to check the connections on the neutral and ground bus bars and could easily tighten each screw a half turn. This solved my problems. I would imagine the original electrician properly tightened these connections but the bus bar might have “stretched” since then.

My previous house was all electric with a 200 amp panel. I found the “extraordinary circumstance” that tripped the main breaker. A utility transformer failed and we lost power for several hours on a winter day. When the power was restored, two heat pumps with strip heat and an electric resistance water heater all came on to recover the drop in temperature during the outage. I turned on the microwave and that was enough to trip the main breaker. What we need is smarter appliances that don’t immediately turn on after a power outage. There needs to be some kind of staging or at least a time delay to prevent this from happening.

When I am home during a power outage, I would like to turn off the heat pump so that I can turn it back on manually after the power is restored and line voltage is stable. Unfortunately, I can’t do that because I have electronic thermostats that cannot be turned off until the power is restored. I guess I could flip breakers, but that is not as convenient.

Allison, monitoring is on my to-do list. You’re right, it is unlikely, although NEC requires and has procedures laid out for main service panel load calculation. This, in my experience, is seldom checked in new construction (single-family), and left to the electrician on the project to do it right.

The EV chargers have become one of the largest and most consistent current users in single-family homes. There are very few, if any, appliances that draw 25+Amp for hours on end.

One advice I would give to those planning on doing major upgrades in preparation for going all-electric: involve your local jurisdiction’s building inspector. An electrical permit to do panel replacement and some rewiring will be inexpensive compared to a roll of Romex these days! Whether you’re doing the work yourself, or hire an electrician, an inspector can be an additional set of eyes to catch mistakes, or even give you tips.

Paul: My quick sum of your loads gives me just a bit less than 200 amps. But the thing about electrical loads (same with heating, cooling, and hot water) is that it would take extraordinary circumstances for them all to be running at once. Have you done any monitoring to see what you actual max current might be?