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.

 

[samgillis]

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.

Mostly lightning protection of the inverter and ATS is what I’m after. But I have read that the actual switching of the ATS from source 1 to source 2 creates transient voltage spikes and can damage the load equipment. So was wondering if by placing the SPD on the output of the ATS would it essentially kill 3 birds with one stone by protecting the downstream loads, ATS board, and inverter output all at once, or if my logic is flawed there should I just put it on the inverter side like you said to protect the inverter and ATS which is my main goal.

 

[pv_n00b]

This "ATS" is an RV product and not suitable for use in a residential system.

50 Amp Transfer Switch

The Go Power! 50 Amp Transfer Switch provides automatic power switching between two separate 120/240 volt AC input sources.

gopowersolar.com

 

[samgillis]

This "ATS" is an RV product and not suitable for use in a residential system.

50 Amp Transfer Switch

The Go Power! 50 Amp Transfer Switch provides automatic power switching between two separate 120/240 volt AC input sources.

gopowersolar.com

What makes it unsuitable

 

[pv_n00b]

What makes it unsuitable

I've used many "RV" products and they are just generally lower quality than the same product intended for residential use. They are designed to be used in an RV that is used a few times a year and does not get that much wear and tear.

 

[pv_n00b]

Also, searching the ETL product listing does not return anything for this company or the product number. I'm not convinced it is listed to UL 1008.

 

[Fred B]

Also, searching the ETL product listing does not return anything for this company or the product number. I'm not convinced it is listed to UL 1008.

551.30, 551.33, 551.40 all require products to be listed for the use. If there is no listing at all, it can't "legally" be used. Listing also could be limited to the RV usage, and thus technically "not listed" in other applications.

 

[pv_n00b]

Seems like this is becoming a discussion on how to do an DIY solar project. Even if the person doing the DIY is a electrician it's better put in a DIY forum.

 

[samgillis]

The question was about best placement of an SPD to protect an inverter and transfer switch, which I figured would warrant some good responses since this forum is compromised of electricians and engineers. What kind of ATS and whether it has anything to do with solar is irrelevant. Anyway, I figured out the answer through another means.