Greetings,
My breaker panel is the brand name "Gould" and all the breakers currently installed are Gould breakers. When I go to buy the 50A GFCI, how will I know if the breaker will fit my Gould service panel?

Since some breakers of different brands can fit into others, what I've done in the past is to remove a similar 30-50 amp breaker that doesn't need to be used while I run to the store, (like the oven or stove), and do a physical side by side comparison at the store.

Note that's what "I Do", (not what others would say you should do). Of course there may be warnings inside the box to only use "Gould" breakers, but if you can't find them?... Lol, I'll be darned if I'm going to swap out an entire panel when a competing GFCI breaker (brand) will work for me!

Now... if there is no compatible brand of GFCI for your Gould box, (or if it is just too expensive) then what I do next is find an electrician or someone that has a standard 50 amp breaker that'll fit the Gould box and buy that, (usually much cheaper). Then get a separate GFCI disconnect to mount outside the house like this one http://spapartsnet.com/p_GFCI_LC50220_842_0_1.html

Hope this helps.

I looked at my existing breakers, and noticed that they all haid "Type QP" printed on them. Well, I go to Lowes to buy my hookup parts, and they have a 50A double pole Type QP breaker. It works just fine. So does my spa now that I have it hooked up.

Stuart

Seimens will interchange with Gould. Hope this helps someone else out.