Hi again, everyone,
I am now looking into wiring the lights, a couple of shaver sockets and an extractor fan for my bathroom.
My plan is to use the 6A light circuit for this, but there are a couple of complications.
1. The light circuit CPC is not continuous. There is definitely a CPC coming out with the twin and earth from the Consumer Unit for the circuit, and there is definitely a CPC on some (but not all!) of the light switches and pendants. But there is no continuity. The reason is almost definitely a 2-core (no earth) cable somewhere in the middle, as I have found them in some other switches and pendants.
2. The lights are mainly wired using the "junction box" method. Basically, junction boxes are littered everywhere, making tracing quite a pain, and providing no neutral at the switches.
3. I want the extractor fan to be a dumb on/off one (for now)
To solve (1) and comply with the regulations, I figured the safest thing to do temporarily would be to borrow the CPC of a nearby socket, by using a 4.0mm² single-core cable in green/yellow. That would reinstate the CPC at least in the bathroom wiring and potentially in other accessories as well. After I finish in the bathroom, I will trace the broken CPC and properly reinstate continuity by rewiring that section with a 2-core and earth.
For (2), to make my life easier and provide me with a neutral at the switch, I thought I would wire the bathroom lights and shaver sockets with the 2-plate method. I will first take the feed from the previous junction box ("Previous Circuit 3 Accessory" in the diagram), feed the switch, then feed the shaver sockets, then go back out from the bathroom to the next junction box ("Next Circuit 3 Accessory" in the diagram). That way, I will at least not have a hidden junction box for the new bathroom wiring, and I will also have a neutral at the switch.
As for the fan, I don't want it to come on with the lights. For now, I only want manual control of it, which I will achieve with a second gang in the light switch, and a 3-core and earth to a 3-pole isolator, then finally the inline fan. The reason for doing it this way is that, in the future, I plan to fit a shelly after the 3-pole isolator to control the fan using humidity and occupancy sensors. That would, of course, make the 3rd core redundant, but I will wire it with 3-core and earth anyway, just in case I decide to take the shelly out later.
Does the above make sense? Any improvements or alterations I should consider? I have also included a diagram describing the above a bit better.
Diagram (please open the PDF instead if the PNG is not high enough resolution)
I am now looking into wiring the lights, a couple of shaver sockets and an extractor fan for my bathroom.
My plan is to use the 6A light circuit for this, but there are a couple of complications.
1. The light circuit CPC is not continuous. There is definitely a CPC coming out with the twin and earth from the Consumer Unit for the circuit, and there is definitely a CPC on some (but not all!) of the light switches and pendants. But there is no continuity. The reason is almost definitely a 2-core (no earth) cable somewhere in the middle, as I have found them in some other switches and pendants.
2. The lights are mainly wired using the "junction box" method. Basically, junction boxes are littered everywhere, making tracing quite a pain, and providing no neutral at the switches.
3. I want the extractor fan to be a dumb on/off one (for now)
To solve (1) and comply with the regulations, I figured the safest thing to do temporarily would be to borrow the CPC of a nearby socket, by using a 4.0mm² single-core cable in green/yellow. That would reinstate the CPC at least in the bathroom wiring and potentially in other accessories as well. After I finish in the bathroom, I will trace the broken CPC and properly reinstate continuity by rewiring that section with a 2-core and earth.
For (2), to make my life easier and provide me with a neutral at the switch, I thought I would wire the bathroom lights and shaver sockets with the 2-plate method. I will first take the feed from the previous junction box ("Previous Circuit 3 Accessory" in the diagram), feed the switch, then feed the shaver sockets, then go back out from the bathroom to the next junction box ("Next Circuit 3 Accessory" in the diagram). That way, I will at least not have a hidden junction box for the new bathroom wiring, and I will also have a neutral at the switch.
As for the fan, I don't want it to come on with the lights. For now, I only want manual control of it, which I will achieve with a second gang in the light switch, and a 3-core and earth to a 3-pole isolator, then finally the inline fan. The reason for doing it this way is that, in the future, I plan to fit a shelly after the 3-pole isolator to control the fan using humidity and occupancy sensors. That would, of course, make the 3rd core redundant, but I will wire it with 3-core and earth anyway, just in case I decide to take the shelly out later.
Does the above make sense? Any improvements or alterations I should consider? I have also included a diagram describing the above a bit better.
Diagram (please open the PDF instead if the PNG is not high enough resolution)
