I have a Westinghouse Cat. No. B10 2020C Type 1 Indoor Enclosure, and I'd like to find the trip curve for the breakers. Any idea where I can find this graph?
I just followed the link. The trip values for the breakers are the numbers on the handles. You have at least 3 different sizes in your panel the red, blue & black (the top left one is the main 240V 100A) the blue and reds are the 120V 15 amp & 20 amp the top right is a 240V and there should be a number on the handle that is its amperage. The numbers you want are the ampacities of the breaker they should trip close to this value. the normal load for a breaker is 80% of the value on the handle. As breakers age or have been tripped many times sometimes they do trip early. If you need the curve values we need the type and brand. The type is normally something like "QP".
Your panel uses type BR breakers -- these are currently made by Eaton. The time-current curves are available here.