I have an off grid system, I have DC lightning arrestors, but I read somewhere that I should have an AC surge arrestor and an AC surge capacitor on the AC output side of my invertor.
When ordering stuff I was told that the DC lightning arrestors are essentual, but the AC was a waste of money. I have had a system for 10 years that doesn't have the AC arrestor or capacitor and have had no problems. Should I add it or is it a waste of money?
Steve
Submitted
13 years ago
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Comments
The lightning arrestor is insurance. You may never have to use it at all. The reason the DC arrestor is considered important is because the aluminum grid of modules on your roof or polemount is a handy path for lightning to discharge through. The ground on your array is more important than the arrestor. The grounding conductor should offer an easier path to the earth than through your inverter. If you add a DC arrestor, then you've got even better insurance that the strike will go to ground some other way than through the inverter.
The AC arrestor is considered less important because the strike would have to enter the inverter through your AC wiring - less likely - but still a possibility.
The arrestors are pretty cheap and easy to install - but look closely at your equipment grounding first. It's possible to have no lightning protection at all, as long as you are never hit...