Where to Place SPD to Protect Inverter/ATS?

[samgillis]

So I have a Go Power 50a ATS that is fed by my inverter as the primary and grid as the backup.

The grid feed is already protected by a Siemens whole home surge protector in the main panel. Does this adequately protect the circuit board of the ATS?

I also just purchased a Midnite Solar SPD and was going to place it in the ATS, just trying to figure out where is best.

I already have surge protection on the DC side into the inverter from the panels and batteries. Would placing the new SPD on the inverter AC out and before the input to the ATS be best? Would this also provide some protection to the inverter even though it’s on the output side? Or would it be best to place it on the output side of the ATS?

 

[tom baker]

With your occupation we are unable to assist per forum rules. Try DIYchatroom.com

 

[tom baker]

Op updated occupation to electrician, unlocked post

 

[pv_n00b]

Your inverter should be protected by the main SPD when connected by the ATS to the utility. When islanded by the ATS you may want another SPD on the inverter side of the ATS. Your inverter might already have an SPD on the AC side, but the included ones are not always the best. When you are islanding what will be the source of the voltage spike you want to prevent? That should drive the location of the SPD.