GREAT questions JD, I compliment you, it shows you are interested and serious, so until Glen arrives I will answer them then see if he agrees or not, likely he will.
Some questions that may seem silly: PS there are NO SILLY QUESTIONS it shows your interest, yours are definite legitimate questions!!!!!!!!
QUESTION: "1) I know the transfer box switches the two "hots and the neutral."
a) NOOOOOOOOOOOOOO NOOOOOOOOOO for 120/240 volt single phase three wire, if the genset is configured as a NON seperately derived source,
YOU DO NOT I REPEAT DO NOT SWITCH THE NEUTRALS, ONLY THE TWO HOTS...Many people prefer that because it ONLY requires a Two Pole Transfer Switch !!!!!!!!!!!!!
b) HOWEVER, if the genset is configured as a seperately derived source YES YES you do have to switch the Neutral, but that requires a more expensive THREE POLE TRANSFER SWITCH. Most Ive seen ony use a two pole transfer BUT THATS NOT TO SAY YOU CANT USE A THREE NOOOOOOOOO PROBLEMMMMMM
QUESTION 1) How is the "earth" ground handled??? Do you need a separate ground stake just for this box???
ANSWER a) If the genset is configured a seperately derived source, similar to the utility transformer, the Neutral is earth grounded to a suitable GroundING Electrode such as driven into earth rod or rods (aka a made electrode)
b) If the genset is NOT configured as a seperately derived source (floating Neutral remember),,,,,,,,,,, And to preserve the concept of SINGLE POINT GROUNDING,,,,,,,,And to satisfy the requirement that all non current carrying conductive devices (just like a metal junction box) are grounded,,,,THE GENNYS CASE FRAME IS WIRED TO THE EQUIPMENT GROUNDING CONDUCTOR
2) The circuits that are being switched, they are feed through the transfer box only??? Then it handles which system supplies them???
ANSWER The Transfer switch switches (DUH lol) the LOAD from one or two sources: Either the UTILITY orrrrrrrrrrr THE GENSET. It has two inputs, Genset and Utility, then you select one or the other AND WHEN ONE IS SELECTED IT LOCKS OUT ANY POSSIBLE BACKFEED TO THE OTHER
Think of it as a DOUBLE POLE DOUBLE THROW DPDT SWITCH for a two pole system or a TRIPLE POLE DOUBLE THROW for a three pole system
SO THERE ARE YOUR ANSWERS JD, now if Glen agrees ???? NOTE he's currently practicing while Im retired lol
God Bless you again good questions, hope this helps you and all the other fine gents here