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What sort of earthing system is it ?I know what you are saying, but an IT system with no Isolating Transformer isn't really.....
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Discuss On the fiddle ______________ in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net
What sort of earthing system is it ?I know what you are saying, but an IT system with no Isolating Transformer isn't really.....
It's Friday night and I started early.... but I'd say still TN-C-S really, Just the S is happening at the CPC bar not the cut-out.What sort of earthing system is it ?
completey agreeThe neutral is disconnected from the meter, so when the switch is open there is only one neutral conductor and that's the same one as the cpc,
The CPC bar. The main earth arrives there which is being misused as a PEN conductor. Imagine the G/Y conductor going to the main switch is blue. We don't have to agree! It's a crazy setup after all. But I think the RCDs would work.where is the separation of the cpc and neutral ?
Yes. Forget the RCD a minute. If current can flow from the MCB through a load and back via the N bar, via the RCD, and the load works, then we've proved it's possible for current to flow. Lower the resistance, all the way to negligable if you like, and lots of current will flow, the and MCB will trip. Or has the 1664 completely broken my brain?Do you think L to Cpc would trip the rcd ? or mcb ?
I need a holiday ....Yes. Forget the RCD a minute. If current can flow from the MCB through a load and back via the N bar, via the RCD, and the load works, then we've proved it's possible for current to flow. Lower the resistance, all the way to negligable if you like, and lots of current will flow, the and MCB will trip. Or has the 1664 completely broken my brain?
For the RCD, anything that goes through it on the L side and doesn't come back on the 'other pole' will cause an imbalance and it will trip.
If you take the meter completely out of the installation and forget it, this is electrically equivalent to every TN-C-S install. Just the point where PEN becomes N and CPC has shifted but it's still upstream of the RCDs.
No worries, it was a most welcome distraction from trying to reassemble an over-locker sewing machine....I'll explain in Arms in a minute...I need a holiday ....
There are two large diameter cables going from the CU to the same point in the head, a blue and a green yellow. The blue passes through the meter and the other doesn't, swapping them won't affect the installation because they're joined anyway, essentially it's just a cable colour changing crossover switch.How would you stop the neutrals from acting as proper neutrals though since they're all physically connected correctly in the board?
I'm trying to visualise a set up whereby the board can look normal but can be switched to use earth as neutral.
What sort of earthing system is it ?
No there isn’t the blue conductor isn’t connected to the meters neutral as the incoming to the meter has been disconnected, leaving a switched shared cpu/neutral connected to the meters output.There are two large diameter cables going from the CU to the same point in the head, a blue and a green yellow.
Thats what I thought but was more concerned with using a single conductor to combine N and Cpc I would have thought could upset an rcd.TN-C
Thats what I thought but was more concerned with using a single conductor to combine N and Cpc I would have thought could upset an rcd.
I don't think it's helpful to label this installation as a TN-C. I understand that in some ways that is correct, but it is causing confusion.In a TN-C installation, the neutral and earthing conductor are combined, thus making the detection of residual current impossible.
A generator cross over switch or a contactor would do what you want.I cant find a ~100a version of the crossover switch in the picture, one that will link straight through L-R and then when turned join L green to R blue as well as L blue to R green. It's easy enough to do in electronics but I guess no-one makes an electric sized version. Sorry for the floppy CAD, turns out windows paint 3D is ----
Reply to On the fiddle ______________ in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net
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