Bobster. Posted August 1 Share Posted August 1 (edited) Long story short: Original installation featured easily broken combiner boxes. Installer replaced, but he fitted a pre-populated combiner and so I have some spares as per the photo. Now there are two surge protectors there (and there are two in the new box). Firstly, do these devices have a life? They were fitted about 6 years ago. They have never tripped, though there was one big lightning strike nearby. Secondly, am I right in thinking that these are single use devices? That if they pop then that's it - you need to replace. So where is this going? The backed up circuits, thus most of the property, are protected, as is the inverter. The inverter has an SP on the AC input side, another on the AC output side (backed up circuits), and also has different SP devices for the DC strings from the panels. So now I am thinking I can use these to protect the outbuildings (swimming pool, tumble drier, washing machine). But I don't know how to connect them. They seem to be in parallell to the AC. Am I right? Also there is a third connection to them marked "PE", currently there's nothing there, but that might be a result of the change of combiner boxes and possible reuse of wiring. So is it fair to ask an electrician to fit these? Since the run from the main DB to the sub DB is quite long, I am thinking that maybe I want to fit one inside the main DB and then a second at the input side of the sub DB. This is leading up to me telling my insurers I have proper surge protection fitted, but they will want a sign off from an electrician, which, I am guessing, means having a fresh COC. Note that I also have a three way change over switch doing nothing. I have an idea for that. I could put that in the main DB and use it to flip the sub-db onto the backed up side so that we can run the whole property during a load shed (most of the time we'd get away with it). Is that a sane idea? Edited August 1 by Bobster. Correct picture file Quote Link to comment Share on other sites More sharing options...
Virwat Posted August 1 Share Posted August 1 (edited) The PE ( Protective Earth) Should be connected to the Earthing Circuit. As for the rest of the wiring, can't see at that angle. Blue wire for Neutral, No. If the indicators on the arrestors green, still ok to use Edited August 2 by Virwat Bobster. 1 Quote Link to comment Share on other sites More sharing options...
Paulcupine Posted August 2 Share Posted August 2 They're not strictly single use. These devices can typically take several (even many) small surges by becoming conductive L/N -> E, but will pop if a single significantly large surge occurs. The indicator should then go red and the unit needs to be replaced. This looks like a 3 phase setup..? I do not know if it is ok to connect on of your phases to a neutral on the SPD. AFAIK there are 3 phase SPDs for the purpose. Quote Link to comment Share on other sites More sharing options...
Bobster. Posted August 2 Author Share Posted August 2 43 minutes ago, Paulcupine said: They're not strictly single use. These devices can typically take several (even many) small surges by becoming conductive L/N -> E, but will pop if a single significantly large surge occurs. The indicator should then go red and the unit needs to be replaced. This looks like a 3 phase setup..? I do not know if it is ok to connect on of your phases to a neutral on the SPD. AFAIK there are 3 phase SPDs for the purpose. They're single phase SPDs. One was for the AC input into the inverter, and the other was on the output side (IE backed up circuits). Thinking about it, I will put the electrician in a quandry. The parts aren't new - so what sort of guarantee can he give? Am I right that they are just hooked up in parallel to the AC line? Quote Link to comment Share on other sites More sharing options...
Virwat Posted August 2 Share Posted August 2 "Am I right that they are just hooked up in parallel to the AC line? " Correct. But not on the supply side. You need to switch the power off to replace/remove the arrestors. In your pic the supply must be from the BOTTOM of those 32A Hager CB Quote Link to comment Share on other sites More sharing options...
Virwat Posted August 2 Share Posted August 2 Have I mentioned that I hate all Electricians that use the bottom of a CB as the supply side. Vaal 1 Quote Link to comment Share on other sites More sharing options...
TaliaB Posted August 2 Share Posted August 2 1 hour ago, Virwat said: Have I mentioned that I hate all Electricians that use the bottom of a CB as the supply side. This should not be done in any case as the industry norm(convention) is line top and load bottom. Sans advise not to do it with conditions. Personally i will not coc such an installation unless the load side and line side is labeled. 6.8.2.3 Circuit-breakers, disconnectors and switch-disconnectors shall not be mounted upside down. Horizontal mounting is allowed unless specifically prohibited by the manufacturer. Any deviation from the convention of connecting line to the top and load to the bottom of switchgear is not recommended. Reverse connection is allowed only if a) it is specifically allowed by the manufacturer, b) "load" and "line" are so marked that they are clearly visible during maintenance, and c) any contradictory marking is not visible after installation Virwat 1 Quote Link to comment Share on other sites More sharing options...
Bobster. Posted August 3 Author Share Posted August 3 Well I just went and checked. The SPDs are connected to the top of the MCBs. There is wire coming out of the ... whatever you call the item on the left, but that's the three way change over switch - top is grid, bottom is AC from the inverter, middle is off. Anyway, they are not in use now, they are just lying in my garage, and I think I could do something useful with them. Or have something useful done. Quote Link to comment Share on other sites More sharing options...
TaliaB Posted August 3 Share Posted August 3 (edited) 21 hours ago, Bobster. said: Thinking about it, I will put the electrician in a quandry. The parts aren't new - so what sort of guarantee can he give? Yes, surge protectors(spd) do lose their effectiveness over time. Each time a surge protector absorbs a surge, its internal components degrade slightly. Over time, or after absorbing a large surge, the protector's ability to shield your devices diminishes, reducing its effectiveness. 1 hour ago, Bobster. said: Anyway, they are not in use now, they are just lying in my garage, and I think I could do something useful with them. Or have something useful done. The transfer switch could be used to power your sub db board as you suggested the transfer switch are not subjected to wear and tear so good to go on that one, speak to your electrician. 21 hours ago, Bobster. said: Am I right that they are just hooked up in parallel to the AC line? Yes normally after the utility isolator on the feeder cable and they are marked L(red) N(black) E(green/yellow)to main earth bar. Edited August 3 by TaliaB Bobster. 1 Quote Link to comment Share on other sites More sharing options...
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