200 amp 240 v at the breaker panel

[Lxnxjxhx]

Let's say with zero load on this service you have exactly 240 volts.
Does this mean that with a full load, 200 amps in this case, you will see a 3% drop in voltage?

I'm getting at the Thevenin equivalent impedance at the breaker panel; I know it's about 1/4 ohm at the outlets.

Also, if there is corrosion upstream, this impedance should increase and you have lights dimming depending on the load.

 

[charlie b]

Does this mean that with a full load, 200 amps in this case, you will see a 3% drop in voltage?

Nope. There is no relationship (at least not one that can be used in a calculation) between the panel's current rating and its internal resistance. Besides, I don't think it reasonable to expect a 3% voltage drop within the panel itself. It is built out of large copper bars, not small wires.

 

[Lxnxjxhx]

Then does anyone know of specs to pass or fail an existing service?

There does seem to be spec limits on the current in neutrals and ground resistance, and I think breakers are not supposed to have over 30 mV across the closed contacts at full load current.