How the heck does a typical home transfer switch work?
https://i.postimg.cc/c49KfVwY/transfer01.jpg

Mine isn't working so I need to figure out how it works first.

o My mains is two hots plus a neutral (i.e., it's not 3 phase)
o There are two duplicate transfer boxes (presumably one per hot phase?)
o Each box has a beefy fist-sized double-ended solenoid
o Each box has what looks like a plastic relay
o And then each box has a fuse strip & a junction strip

That's pretty much it, where I'm not sure which "side" of the main circuit
breaker this two-box transfer switch is on yet.

Before I can troubleshoot, I need to know how it works.
https://i.postimg.cc/N0wQX4Jm/transfer02.jpg

1. The beefy double-ended solenoid is labeled:
"Generac transfer switch pn #71340, 250VAC/100A"
"This transfer switch is for use with control module ass'y
#75595 - #79844 - #83494"
https://i.postimg.cc/TYq0GY8x/transfer03.jpg

2. The plastic relay is labeled
o Deltrol controls, 166F DPDT, coil 12 VDC,
o 1/3 HP 13 AMP 120 VAC
o 1/2 HP 13 AMP 277 VAC
o 3/4 HP 3 AMP 600 VAC
o 10 AMP 28 VCD
o 8600, 20552-81, 9346
https://i.postimg.cc/s20K8nkZ/transfer04.jpg

3. The 4 fuses are each labeled either Buss BBS-4 or BBS-5.
https://i.postimg.cc/DwTNdMhv/transfer05.jpg

4. The junction strip is labeled
o Utility 1
o Utility 2
o Load 1
o Load 2
o blank
o 23
o 194
https://i.postimg.cc/tgDN6rqM/transfer06.jpg

What is the role of each of those 4 parts in this transfer switch?
https://i.postimg.cc/V6L4ZxZw/transfer07.jpg