Dillsue Posted August 17 Share Posted August 17 Your DNO wants to know where the generators are isolated so they can isolate them if they're working on your supply. You probably need a lockable AC isolator on the Luxpower unit and a note stating where in the house the isolator is. A copy of the drawing should be pinned up where the DNOs incoming supply/cutout fuse is located. When our DNO upgraded our transformer they checked the drawing and checked both systems were shutdown although they didn't lock off the isolators. They do actually use the info you give them! 1 Link to comment Share on other sites More sharing options...
sharpener Posted August 18 Share Posted August 18 20 hours ago, Dillsue said: When our DNO upgraded our transformer they checked the drawing and checked both systems were shutdown although they didn't lock off the isolators. Don't quite see why they bothered. Yes it's the correct process but it would have been quicker and more certain if they had just pulled the supply fuse while they worked on the transformer. Also you would then have been able to run off your batteries while they did it whereas with all generators shut down that wouldn't have been possible. Link to comment Share on other sites More sharing options...
Dillsue Posted August 19 Share Posted August 19 13 hours ago, sharpener said: Don't quite see why they bothered. Yes it's the correct process but it would have been quicker and more certain if they had just pulled the supply fuse while they worked on the transformer. Also you would then have been able to run off your batteries while they did it whereas with all generators shut down that wouldn't have been possible. Yep way easier.......but that's not the way industry works as its not classed as a positive isolation! Nothing to stop anyone inadvertently putting a spare fuse from the van back in. With lockable isolators theres a positive action with a hacksaw required to remove a lock so negligble scope for accidents. Not applying locks was the chargehands call but almost certainly breaching company procedures!! Link to comment Share on other sites More sharing options...
sharpener Posted August 20 Share Posted August 20 On 19/08/2024 at 08:02, Dillsue said: Yep way easier.......but that's not the way industry works as its not classed as a positive isolation! Nothing to stop anyone inadvertently putting a spare fuse from the van back in. If they are not going to complete the procedure and lock the isolators then it's easy for the householder to turn them back on without thinking. Better for them to put the fuse carrier back sans fuse and seal it with a wire seal, not many ppl have that size fuse in their junk box. Doesn't make much difference either way, provided your equipment is compliant it will shut down and self-isolate on interruption of the supply anyway. Isolators with plastic rotary handles and plastic bodies don't need a hacksaw. Having just spent £10 on a padlock for an outdoor isolator I was surprised how little protection it affords, looks like a good pair of wirecutters would easily notch out the plastic round the staple. Link to comment Share on other sites More sharing options...
Dillsue Posted August 20 Share Posted August 20 20 minutes ago, sharpener said: If they are not going to complete the procedure and lock the isolators then it's easy for the householder to turn them back on without thinking. Better for them to put the fuse carrier back sans fuse and seal it with a wire seal, not many ppl have that size fuse in their junk box. Doesn't make much difference either way, provided your equipment is compliant it will shut down and self-isolate on interruption of the supply anyway. Isolators with plastic rotary handles and plastic bodies don't need a hacksaw. Having just spent £10 on a padlock for an outdoor isolator I was surprised how little protection it affords, looks like a good pair of wirecutters would easily notch out the plastic round the staple. For clarity- don't rely on an inverter shutting down as a safe way to isolate any inverter/generator/battery, ever. There's loads of old/cheap and potentially non compliant inverters around any or all of which can go faulty. Lockable AC isolators are specified for a reason throughout the world of electrical power. Of course you can defeat a cheap lock with a hacksaw/bolt cutters/sidecutters, but thats a deliberate act. Putting a fuse carrier back in can be done inadvertently and may not be questioned by whoevers trying to get the supply back on. On the other hand taking a hacksaw to a lock on a locked red and yellow isolator would set alarm bells ringing for anyone with even the smallest degree of electrical competence. Anyone with basic understanding of electrical working can come up with a way of working giving a level of safety that suits them and their appetite for risk. Anyone taking guidance from others on an internet forum should use the installed isolators and lock/cable tie them off if there's anyone else around while you're working on isolated kit. Link to comment Share on other sites More sharing options...
Thorfun Posted August 21 Author Share Posted August 21 i've created a whole new single line diagram which i think is now much better. any comments before i submit to DNO? Link to comment Share on other sites More sharing options...
sharpener Posted August 21 Share Posted August 21 Looks clear and easily understandable. Why is there the 3phase lockable isolator as well as the single phase one, is it for future expansion? Under IET CoP for EESS there should be a lockable two-pole isolator on the input to the Luxpower inverter, you could argue that it is adequate to lock off the dedicated RCD (if this has got the holes in the handle for one of those cheapo mcb locks) - so mention it is lockable. May be show power flow, data (wired) and data (wireless, if any) with different kinds of line? May be show rating of DNO fuse and have the principle flow from left to right? Aren't the batteries 3.2 kWh not kW? (Doesn't sound to me a good match 10.5 kW PV though, will only store 40 mins of full output) Link to comment Share on other sites More sharing options...
Thorfun Posted August 21 Author Share Posted August 21 3 minutes ago, sharpener said: Why is there the 3phase lockable isolator as well as the single phase one, is it for future expansion? we have a 3-phase supply but are only running the house off a single phase. hence the single phase smart meter. so, yeah, basically future expansion if needed. 4 minutes ago, sharpener said: Under IET CoP for EESS there should be a lockable two-pole isolator on the input to the Luxpower inverter, you could argue that it is adequate to lock off the dedicated RCD (if this has got the holes in the handle for one of those cheapo mcb locks) - so mention it is lockable. isn't that excessive though? if they're working on the lines then switching off via the 3-phase lockable rotary isolator would suffice, no? i can easily update the drawing to say it's lockable though, although that is not true. 5 minutes ago, sharpener said: May be show power flow, data (wired) and data (wireless, if any) with different kinds of line? i did have arrows and stuff but figured everything is 2-way flow anyway so why bother! i also found some other SLDs on a Victron forum and they didn't have flow direction so i didn't bother. 7 minutes ago, sharpener said: May be show rating of DNO fuse and have the principle flow from left to right? i can add the 3 x 100A DNO fuses. not sure what you mean by 'principle flow from left to right' though. 8 minutes ago, sharpener said: Aren't the batteries 3.2 kWh not kW? (Doesn't sound to me a good match 10.5 kW PV though, will only store 40 mins of full output) whoops! don't let @SteamyTea know i got the units wrong. i'll never live it down. Updating now. the batteries are expandable. i can only afford 6.4kWh of storage at the moment. but can easily add extra 3.2kWh units to increase the capacity as and when funds allow. it's not a huge amount of storage but it reduces our night time usage a bit. Link to comment Share on other sites More sharing options...
SteamyTea Posted August 21 Share Posted August 21 1 hour ago, Thorfun said: don't let @SteamyTea know i got the units wrong Just make sure it is correct on the application. 1 Link to comment Share on other sites More sharing options...
sharpener Posted August 21 Share Posted August 21 3 hours ago, Thorfun said: isn't that excessive though? if they're working on the lines then switching off via the 3-phase lockable rotary isolator would suffice, no? i can easily update the drawing to say it's lockable though, although that is not true. Yes but that is what the IET says on the matter and their Code of Practice is incorporated in BS7871 by reference so mandatory under the Building Regs. I did borrow both the first and second editions from their library prior to my DiY install but I can't remember the rationale. It might be so you can work safely on the inverter itself. In my case this makes some sense as I have a bypass switch so the inverter can be taken out of service entirely with the rest of the system live. More importantly if you have off-grid/UPS capability they also require you to have a separate earth electrode as you cannot rely on the DNO's PME earth terminal in case they are working on their side of the cutout and have disconnected their cable. Not many installers know about either of these requirements. i did have arrows and stuff but figured everything is 2-way flow anyway so why bother! i also found some other SLDs on a Victron forum and they didn't have flow direction so i didn't bother. No I meant use different kinds of line (solid, dashed, chain-dashed etc) for the different kinds of link. i can add the 3 x 100A DNO fuses. not sure what you mean by 'principle flow from left to right' though. You have got the logical flow from DNO intake to the final circuits from top to bottom (more or less) but personally I would go for left to right like this though it is largely a matter of taste. whoops! don't let @SteamyTea know i got the units wrong. i'll never live it down. Updating now. the batteries are expandable. i can only afford 6.4kWh of storage at the moment. but can easily add extra 3.2kWh units to increase the capacity as and when funds allow. it's not a huge amount of storage but it reduces our night time usage a bit. Yes, I started with 7.1 kWh of Pylontecs but added a third module after the first winter. 1 Link to comment Share on other sites More sharing options...
sharpener Posted August 22 Share Posted August 22 17 hours ago, sharpener said: BS7871 Typo, BS7671 Link to comment Share on other sites More sharing options...
Thorfun Posted August 22 Author Share Posted August 22 I uploaded the required drawings and my application is now complete. I used the Smart Connect portal and I received the 'your application is complete' email pretty soon after. so they either have some form of AI or image recognition software to check the drawings or they don't care. either way, I'm happy. 🙂 Link to comment Share on other sites More sharing options...
trialuser Posted August 22 Share Posted August 22 Well done. I take it you're not with SP energy networks in Southern Scotland then. They won't accept G99 on the portal. But they did accept an EVCP. Link to comment Share on other sites More sharing options...
Thorfun Posted August 22 Author Share Posted August 22 3 hours ago, trialuser said: Well done. I take it you're not with SP energy networks in Southern Scotland then. They won't accept G99 on the portal. But they did accept an EVCP. Nope. UK Power Networks. South East England. Link to comment Share on other sites More sharing options...
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