400 Amp Service TVSS?

[busman]

I had a request the other day to install a whole house surge suppressor. This would be my first on a 400 Amp (2 loadcenter) service. The question is - is there any benefit to placing one suppressor on each loadcenter? My gut feel (not being an expert in lightning protection) is that the benefit from the second unit would be marginal. I would think that once the MOV's close the path to ground that this would protect both loadcenters.

I also understand that the high voltages in lightning strikes do not behave in an intuitive fashion. Any facts, opinions or manufacturer data would be apprectiated.

Thanks,

Mark

 

[ron]

Re: 400 Amp Service TVSS?

If the two subpanels are located a distance apart (different feeder lengths), then two TVSS's may be appropriate, one at each sub.

 

[busman]

Re: 400 Amp Service TVSS?

The situation is the usual side-by-side 200-Amp 42-space loadcenters fed from a twin-lug meter socket.

 

[templdl]

Re: 400 Amp Service TVSS?

As an applications engineer for as major electrical manufacturer when applying our TVSS devices, definitely, one TVSS in each panel each TVSS fed from a breaker located as close to the main breaker as physically possible becasue the panels are actually in parallel as you described it.
Should there have been a 400a main panel which feed a subpanel then a TVSS located next to the main breaker in the main panel would have protected the down stream panel.
If the TVSS could be fed from the twin lugs (which it can't be of course) then it could have protected both panels.

 

[steve66]

Re: 400 Amp Service TVSS?

So you have two feeders from the meter can??
How far from the meter can are the panels??
If it is anything more than "thru the wall" I think I also have to vote for 2 surge suppressors.

Steve