Just had a new transfer switch installed, why do you ask, didn't get it installed before trip to Canada last summer and you guess it

lost the darn switch.

Now I plan to install it

but have a question

want to protect both GEN & 50 AMP service into coach.
Have two relays upper one has GEN left side and 50 amp service on right side. From left side where Gen connects three straps go from top relay to bottom relay left side thru operating relay to service wiring to service panel switch box.
I want to place the surge protector in series with these straps

between the upper an lower relays so all internal ckts are protected from both GEN & 50 AMP services.
Does anyone see a problem with this?

Have seen surge connected after bottom relay to service panel but question why it can not go in series with straps, before bottom relay.
All wiring is three wires, two hots and gnd, proper gage of course.

"007"