Thorfun Posted December 1, 2020 Share Posted December 1, 2020 Hi all. I’m in the middle of removing an external run from our existing house RCD. I’ve removed the live and neutral but I’m not sure if I have to remove the blue wire which looks like it’s the shared neutral. any electricians on here able to help please? The power is currently off so could do with finding out soon! here’s a photo Link to comment Share on other sites More sharing options...
Onoff Posted December 1, 2020 Share Posted December 1, 2020 That's an RCBO so it has a flying blue neutral? Is that what you're on about? Link to comment Share on other sites More sharing options...
Onoff Posted December 1, 2020 Share Posted December 1, 2020 If so then I'd just disconnect and make safe (at least tape those ends or remove completely), the incoming cable to your circuit. There'll be an earth wire too. Leave the RCBO in and it's blue & white wires connected. You might want to use it for something else later on. Link to comment Share on other sites More sharing options...
Thorfun Posted December 1, 2020 Author Share Posted December 1, 2020 16 minutes ago, Onoff said: That's an RCBO so it has a flying blue neutral? Is that what you're on about? Exactly what I’m talking about 13 minutes ago, Onoff said: If so then I'd just disconnect and make safe (at least tape those ends or remove completely), the incoming cable to your circuit. There'll be an earth wire too. Leave the RCBO in and it's blue & white wires connected. You might want to use it for something else later on. im going to pull out the live and neutral and earth and leave the blue cable in the RCBO. thanks @Onoff Link to comment Share on other sites More sharing options...
Thorfun Posted December 1, 2020 Author Share Posted December 1, 2020 @Onoff tracing the eart cable is proving tricky! Any secret ways of doing so or is it just trace one at a time until you find the right one. this is a photo of the cable I want to remove in its housing. The earth is separate from the live and neutral and this is the whole fuse box. You can see the cable to remove below it Link to comment Share on other sites More sharing options...
Thorfun Posted December 1, 2020 Author Share Posted December 1, 2020 Hmmm....and I can’t seem to pull out the red and black cables. I think I’ll just tape them off. That cable runs outside to another fuse box for the pool house which is coming down to make way for our new house. So I might eventually reuse that for a supply for the builders so I can possibly reconnect it at a later date. do I need to remove the earth cable as well? Or can that stay connected? so simply tape up the removed red and black and then put the cover back on? Link to comment Share on other sites More sharing options...
Onoff Posted December 1, 2020 Share Posted December 1, 2020 7 minutes ago, Thorfun said: @Onoff tracing the eart cable is proving tricky! Any secret ways of doing so or is it just trace one at a time until you find the right one. this is a photo of the cable I want to remove in its housing. The earth is separate from the live and neutral and this is the whole fuse box. You can see the cable to remove below it OK that's 2-core steel wire armoured. The earth path goes from the earth bar in the CU via the bit of earth wire to that galvanised adaptable box. The earth path will likely continue via the stranded armoured around the cable. Those strands will be connected to the brass gland. Tug / push up that earth wire in the galv box and you might see it move on the earth bar in the CU. No prob leaving that earth wire in situ to the galv box. Are you removing the swa cable completely? 1 Link to comment Share on other sites More sharing options...
Thorfun Posted December 1, 2020 Author Share Posted December 1, 2020 2 minutes ago, Onoff said: Are you removing the swa cable completely? Yes, eventually when this house is demolished after we’ve built the new one. I was just thinking about reusing it for a site electricity supply if I can dig it up and attach the pool house RCD to a housing outside. Would save running cables through windows for builders and would also allow us to isolate from inside the house when no one is using it. so if I just leave the earth connected and tape up the live and neutral all is good? Link to comment Share on other sites More sharing options...
Nickfromwales Posted December 1, 2020 Share Posted December 1, 2020 Deffo reuse for site power. Extension leads have dreadful power ratings and things like chop saws suffer badly. Always good to have a high power supply. Yip, just tape them off and cable tie them so they can’t go touching anything. 1 Link to comment Share on other sites More sharing options...
TonyT Posted December 1, 2020 Share Posted December 1, 2020 The swa has been glanced in a metal box and the live and neutrals are passing through the box to prevent a joint. The earth cable at the bottom of the box is supplying a flying lead to an earth somewhere else? Without seeing the whole installation at least that looks well done Link to comment Share on other sites More sharing options...
TonyT Posted December 1, 2020 Share Posted December 1, 2020 Just leave the blue and white wires connected they aren’t doing any harm just remove the load cable the red and black into the metal box, put some connector block on them and put the lid back Link to comment Share on other sites More sharing options...
Thorfun Posted December 1, 2020 Author Share Posted December 1, 2020 1 minute ago, TonyT said: Without seeing the whole installation at least that looks well done That’s good to know. Hopefully this place will be demolished in 18 months though as we’ll have a lovely new house to live in. Link to comment Share on other sites More sharing options...
Nickfromwales Posted December 1, 2020 Share Posted December 1, 2020 4 minutes ago, TonyT said: The swa has been glanced in a metal box and the live and neutrals are passing through the box to prevent a joint. The earth cable at the bottom of the box is supplying a flying lead to an earth somewhere else? Without seeing the whole installation at least that looks well done The metal box has been utilised as a transition so the SWA can be made off to a bonded metal structure. A bit OTT but hey-ho. The earth lead does not service something else, it’s the critical earth bond strapper that bonds the SWA sheath and is functional. Link to comment Share on other sites More sharing options...
TonyT Posted December 1, 2020 Share Posted December 1, 2020 Maybe the consumer unit is plastic, so makes sense and if I was in that situation would probably do the same Nice to see brass nuts and bolts used instead of roofing bolts! Link to comment Share on other sites More sharing options...
Thorfun Posted December 1, 2020 Author Share Posted December 1, 2020 thanks all. it is removed, taped up and secured and the power is back on with no ill effects that I can see yet! now I can crack on with removing the RCD in the pool house. Link to comment Share on other sites More sharing options...
ProDave Posted December 1, 2020 Share Posted December 1, 2020 Another vote to re use that as a site poser supply cable suitably relocated to somewhere not in the way of the new build. You will need to change that for a B16 rcbo to feed a 16A commando socket. And most important, at the site socket do NOT connect the SWA to anything. Terminate the SWA into a plastic gland into a plastic box, and connect the site socket earth to a local earth rod driven into the ground. Link to comment Share on other sites More sharing options...
Thorfun Posted December 1, 2020 Author Share Posted December 1, 2020 7 minutes ago, ProDave said: Another vote to re use that as a site poser supply cable suitably relocated to somewhere not in the way of the new build. You will need to change that for a B16 rcbo to feed a 16A commando socket. And most important, at the site socket do NOT connect the SWA to anything. Terminate the SWA into a plastic gland into a plastic box, and connect the site socket earth to a local earth rod driven into the ground. I have found an external earthing rod near to where I think the site supply will go. but, to be honest, electricity scares me and so I think I'll get a sparky in to connect up that site supply. Link to comment Share on other sites More sharing options...
redtop Posted December 1, 2020 Share Posted December 1, 2020 26 minutes ago, Thorfun said: I have found an external earthing rod near to where I think the site supply will go. but, to be honest, electricity scares me and so I think I'll get a sparky in to connect up that site supply. Yeah worth doing if not sure. Don't want to be responsible for some site worker getting a shock!also they can then test the earth rod properly to make sure its safe 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted December 1, 2020 Share Posted December 1, 2020 Mark up the cables so others know what they are. Really annoying finding a disconnected cable and having no idea what it is. 1 Link to comment Share on other sites More sharing options...
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