Quick Rezi calc

[TMEC EV Division]

Hey forum, thanks for having me. A partner and I are starting up a EV charger heavy rezi shop. So far the interest has been steady in the chargers and such.

I am running up against the question "will my EV charger fit in my 100A, 150A, Etc. panel", a lot more than I ever had but that's what we are trying to do so...

I am looking for better faster way of calculating that than I am doing. I'm trying to avoid finding the nameplate on all of the appliances in the house. Ft2 helps. clamping on amp meters and trying to get the homeowners "recreate thanksgiving" is an interesting one... The most promising idea I have heard is to have the customer ask for a year worth of hour by hour meter reads from the electric company in an excel sheet that Portland General Electric offers. Not sure about other ECs but you can download it from PGEs web page here. That has seemed hit and miss and you gotta get the customer to get you that file which is just another step. Sometimes they don't have access to their account etc.

So I guess I am asking for what does the hive mind do when they get asked... "Will this Xamp load fit in my Xamp panel?"

I know the book answer. Looking for creative and reliable to see how close I may be to needing to do it all the way. I will take your answers off the air. Thanks in advance.

 

[Fred B]

No short cut to doing it right.
Under normal conditions a 100A resi service will not support the addition of a level 2 32A or 40A EVSE. A 150A resi service maybe, even a 200A is only maybe depending on other loads. There are exceptions of course thus the need to do a calculation.

Around here the POCO doesn't record the data needed to calculate actual peak loads, and you can't use kWh to calculate it.

 

[electrofelon]

Getting demand data from the utility works great, but as Fred said, many/most POCOs don't have demand data for residential meters. In those cases where demand data is not available, you could invest in your own logger and put it on the service for 30 days.

There are load management devices for EV chargers which could be helpful in those situations with small 100 amp services.