You guys are never going to take the Village Idiot Cap away from Me, so don't even try to!!
I also hold the title of "Anesteticly Induced Messages", which suppliments the Village Idiot Achievement Award.
Now on the serious side, '66 gave a good suggestion as to using Volt-Amps [or KVA] to figure a system's rating [or service's rating].
To answer Boscodog's original question in as few words possible [oh, how I've said that so many times before
For a simple 100 amp, 120/240 volt 1 phase 3 wire service, the panel would be able to draw a maximum of 100 amperes per Ungrounded Conductor [hot].
That loosely translates into two  100 amp hots at 120 volts [line to neutral], or a total of 100 amps at 240 volts [line to line].
It's more proper to say that the panel / service is rated at 100 amps, because that's the highest load that can be drawn on one "hot" conductor, or through one pole of the main breaker, at one time.
It will, as you asked, have a combined total of 200 amps when using Line to Neutral [120 volt] loads only - so it's not really totally incorrect to say that, just not completely and technically correct.
That alone must be a mountain of jibberish to understand
As Sparky mentioned in the first reply, the ampacity [size] of the wire will be the primary thing to determine maximum current.
This plus the main breaker's rating will determine the maximum amperage a panel can draw [continuously and without LCL], provided it's not more than the panel's designed for [like using a 150 amp breaker for the main on a 100 amp panel with 100 amp bus bars].
Can't really use the combined totals of the branch circuit breakers to do this.
Also, as '66 mentioned, the typical 120/240 VAC 1 phase 3 wire service will have a total Volt-Amp capacity of 12,000 VA [12.0 KVA] per Line to Neutral load [hot to neutral], for a combined total of 24,000 VA [24.0 KVA]. The 12.0 KVA is 120 volts times 100 amps.
Consequently, the total Volt-Amp capacity for the same panel, using Line to Line loads [240 volts, or both "hots"] is also 24,000 Volt-Amps [24.0 KVA].
Multiply 240 volts times 100 amps, which equals 24,000 VA [24.0 KVA].
Please pardon the vague and slang terms I have used in this message. I'm trying to make it easier to comprehend [any luck ??
Other than "twilight Zone Stuff", what did you think of the topics and threads in the Theory discussion area?
Let us know!!