Hi Guys & Girls,
It's been a while, hope everything is good.
I have an issue that's proving to be a bit of a head scratcher. Please bear with me.
Recently carried out an EICR at a small empty basement flat. It's a TT, 100mA RCD at intake, dual split load at the board. Lots of issues identified, reverse polarity at sockets, no R2's at lights, non-fire rated downlights installed into lath & plaster ceilings that had been over boarded leaving a gap between the new ceiling & the old with wires fed down the gap rather than over the top, no access to existing lighting junction boxes/ceiling rose points, a junction box stuffed behind a KO box in order to extend the cable, spurs with multiple outlets off a 32a ring final without the appropriate over current protection & generally totally cack wiring throughout.
I won the quote to do the remedial works. One of the recommendations was to replace the existing Wickes specials for fire rated downlights. All the existing fittings had mains LED lamps in them, I changed the fittings for the integrated type, a brand I use all the time & have never had issues with.
I started with the kitchen, once finished I switched them on & they would start to intermittently flicker & pulse but finally settle down. Checked connections at lights & switch, no probs there. So I start to dig a bit deeper. I identified reverse polarity at the feed to the first light which I found strange as I didn't come across it previously, in fact I had a R1 + R2 when I carried out the EICR. Prior to identifying the reverse polarity I also found that if I plugged a load into any of the socket circuits (my Henry Hoover) the lights would pulse & the the RCDs would trip, one after the other (just the 30mA's in the board). After disconnection of the kitchen lights the circuit no longer tripped when I used the vacuum although there were other existing lights on the circuit that come on & were fine.
So I think, must be the reverse polarity at the kitchen lights. Despite not having access to the junction box above the ceiling (I can see it with my camera but can't reach it, but that's another story) I thought I had it cracked.
Been back there today & installed further replacement downlights on a different circuit. Lo & behold, same issue where it hadn't existed before, if I plugged my battery charger in the lights would flicker & pulse for a short time & then settle. If I plug the vacuum in it's the same as before, the RCDs trip. If the lights are switched off at the board everything else seems OK.
The thing that is baffling me is that this issue didn't appear to exist before I changed the lights over. The only thing I could think of is that GU10's can be fitted either way round but wondered whether the replacements I have used are polarity sensitive (for want of better expression). Thus, if there is an unidentified polarity issue between what would of been the existing lighting point & the more recently installed downlights (not mine, the ones I have removed) fitted with GU10's then this wouldn't happen.
I thought of maybe a borrowed neutral but this problem as far as I know didn't exist previously, the board is configured the same with the exception of the ring final which I have moved from the right hand RCD to the left following a tidy up of the rats nest inside the CU.
I'm a bit frazzled after a weekend of working & finding it a little difficult to get my head round.
Any thoughts would be most welcome.
It's been a while, hope everything is good.
I have an issue that's proving to be a bit of a head scratcher. Please bear with me.
Recently carried out an EICR at a small empty basement flat. It's a TT, 100mA RCD at intake, dual split load at the board. Lots of issues identified, reverse polarity at sockets, no R2's at lights, non-fire rated downlights installed into lath & plaster ceilings that had been over boarded leaving a gap between the new ceiling & the old with wires fed down the gap rather than over the top, no access to existing lighting junction boxes/ceiling rose points, a junction box stuffed behind a KO box in order to extend the cable, spurs with multiple outlets off a 32a ring final without the appropriate over current protection & generally totally cack wiring throughout.
I won the quote to do the remedial works. One of the recommendations was to replace the existing Wickes specials for fire rated downlights. All the existing fittings had mains LED lamps in them, I changed the fittings for the integrated type, a brand I use all the time & have never had issues with.
I started with the kitchen, once finished I switched them on & they would start to intermittently flicker & pulse but finally settle down. Checked connections at lights & switch, no probs there. So I start to dig a bit deeper. I identified reverse polarity at the feed to the first light which I found strange as I didn't come across it previously, in fact I had a R1 + R2 when I carried out the EICR. Prior to identifying the reverse polarity I also found that if I plugged a load into any of the socket circuits (my Henry Hoover) the lights would pulse & the the RCDs would trip, one after the other (just the 30mA's in the board). After disconnection of the kitchen lights the circuit no longer tripped when I used the vacuum although there were other existing lights on the circuit that come on & were fine.
So I think, must be the reverse polarity at the kitchen lights. Despite not having access to the junction box above the ceiling (I can see it with my camera but can't reach it, but that's another story) I thought I had it cracked.
Been back there today & installed further replacement downlights on a different circuit. Lo & behold, same issue where it hadn't existed before, if I plugged my battery charger in the lights would flicker & pulse for a short time & then settle. If I plug the vacuum in it's the same as before, the RCDs trip. If the lights are switched off at the board everything else seems OK.
The thing that is baffling me is that this issue didn't appear to exist before I changed the lights over. The only thing I could think of is that GU10's can be fitted either way round but wondered whether the replacements I have used are polarity sensitive (for want of better expression). Thus, if there is an unidentified polarity issue between what would of been the existing lighting point & the more recently installed downlights (not mine, the ones I have removed) fitted with GU10's then this wouldn't happen.
I thought of maybe a borrowed neutral but this problem as far as I know didn't exist previously, the board is configured the same with the exception of the ring final which I have moved from the right hand RCD to the left following a tidy up of the rats nest inside the CU.
I'm a bit frazzled after a weekend of working & finding it a little difficult to get my head round.
Any thoughts would be most welcome.
