[StrongEagle]

I want to size a portable generator for my house for this season's hurricanes.

I want to know what my maximum draw is with the air conditioner running, and with everything except the AC... OK... no electric stove, dryer, or oven, either... all heavy current draw appliances.

Will I get accurate readings if I turn everything on in the house, then use a clamp around meter as below, to measure the current draw on each leg coming into my breaker panel?

And secondly, is it legal in Houston to use a mechanical lockout between the line mains and the breakers controlling a generator as opposed to installing a transfer switch? For example, something like the interlock shown in the second image.

TIA

 

[Half-fast eddie]

Why not pit in a transfer switch, and connect only the loads you need on the generator. Leave off the stove, dryer etc.

 

[StrongEagle]

Why not pit in a transfer switch, and connect only the loads you need on the generator. Leave off the stove, dryer etc.

Cost and complexity. I don't care about outages of an hour or two... maybe I'd fire up the generator, maybe not. But, I've been without power for 11 days after a hurricane (last on the list of lines to repair) and I was without power for two days during the last Texas freeze. A mechanical lockout seems to be the cheapest.

 

[rjniles]

Measure the amps on each leg and add them together, multiply by 240 will give you wattage. Do it several times over the course of the day, throw out the high and low and take an average.

You need to ask the local electrical inspector if they accept a mechanical lockout.