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Discuss Surge protection devices (SPD) in the UK Electrical Forum area at ElectriciansForums.net
You can have two structures side by side with one taller than the other but there is no guarantee it will not strike the shorter over the taller one.Really?
No Mate it was just that your's was the last post, so I added my answer to it, wasn't questioning your post in any way, sorry if it caused any misunderstanding, if it did it was unintentional.Not sure if you intended to reply to me Pete, but my point was replying to the comment earlier about height not affecting risk of lightning strike. Which it does.
You can have two structures side by side with one taller than the other but there is no guarantee it will not strike the shorter over the taller one.
No Mate it was just that your's was the last post, so I added my answer to it, wasn't questioning your post in any way, sorry if it caused any misunderstanding, if it did it was unintentional.
Thank's mate, last thing on my mind was trying to upset people.No worries at all mate.
Thank's mate, last thing on my mind was trying to upset people.
It's the first thing on my mindThank's mate, last thing on my mind was trying to upset people.
We knowIt's the first thing on my mind
http://www.purgethesurge.com/pdf/Presentation/TPS3_Consultant_Presentation_CE_2013.pdfNo one on this forum is experienced with fitting SPD's and can answer any of my questions?
Do I need switchfuses or isolators? Why fused at 63a on a 20a circuit?
Please!
Hi guys, hopefully someones going to be able to point me in the right direction here.
We do a lot of work for a small retirement home locally that has recently decided to fit lightning protection. We've pretty much been strong armed into fitting SPD's on behalf of the lightning firm (LF). Being honest I don't have a great deal of experience with them and tried to sidestep the job. No such luck!
The lightning firm(LF) are supplying SPD's, but have supplied little further information. What they have provided seems inconsistent and vague. IMO they don't really seem to 100% know what they are talking about.
1.We have a 3 phase SPD to be fitted at the main intake position. There is a 3 phase DB here, but it has no spare ways. LF have said we need to split the tails and fit a 3 phase switchfuse isolator before connecting to SPD in adjacent enclosure.
2.We have 2x SWA cables running external around the building which we are told need SPD's at the load end. These supply a 3 phase washing machine and a 3 phase cooker (20A each). LF have been pretty vague here and sometimes use the word 'isolator' and sometimes 'switchfuse' and don't appear to know the difference. They want us to cut into the SWA before the existing appliance isolator and fit a 63A switchfuse (or isolator - who knows). This would isolate the SPD.
I'm not sure why 63A has been specified?
I'm not sure if I need to fit a switchfuse or an isolator? I'm not even sure what would stop someone turning it off by accident?
If I cut into the SWA at the load end I'm going to need to double up the cables in the supply side of the isolator - doesn't seem like the greatest design?
Can anybody offer some help/point me in the right direction here. I don't like just blindly following instructions that don't make sense to me.
Cheers
No one on this forum is experienced with fitting SPD's and can answer any of my questions?
Do I need switchfuses or isolators? Why fused at 63a on a 20a circuit?
Please!
Thanks marconi. Reading through those instructions actually gives slightly more detail than the hardcopy ones I received from the firm doing the lightning conductors.
The SWA supplies are both 6mm 4core SWA with 20A OCPD. Why would they then specify 63A switchfuse or isolator?!
If the upstream OCPD is 20A then the SPD can have a lower OCPD as stated in the installation instructions. Some form of isolation of the SPD is required if one wants to avoid turning off all power while servicing the SPD. If this is not an issue then the SPD can share the isolation provided for the cables and loads.
Ive also been wondering if I need to fit a switchfuse, or if I could fit an MCB in the same enclosure as the DIN rail mounted SPD. This would keep the tails to the SPD shorter and obviously keep the costs down to my customer.
It makes no difference.
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