I am replacing the light fitting in my porch. The 1.0mm T&E cable goes out of the back of the fitting, through the wall into the hall, down inside about 9" of plastic trunking, and into the 16mm pattress box holding the switch.
The new fitting (LED with PIR etc) was clearly designed by someone trying to squeeze everything into the smallest possible space without any thought about how it might be installed in practice
There is an open-fronted black plastic rectangular box with a M16 knock-out in the back which will be screwed the wall. The actual lamp unit is fitted onto a open-backed metal box which is bolted over the plastic box like a cover.
The T&E cable (a new length to replace the old) will come into the back almost directly behind the 4-way connector block and the cores will need to be bent at 90 degrees about 1/2" from their end in order to feed them into the screw terminals. The problem is that there is simple no room inside the unit, once assembled, to accommodate any slack in the T&E cores, so when the front is placed over the back the T&E is forced back through the wall. If I then bring it straight down into the trunking and into the switch, there is no way that the light can be disassembled for any reason without first removing the T&T tail from the light switch
One possibility seems to be to use 3-core flex instead of T&E, as a trial shows that the extra flexibility of the multi-stranded cores can allow for a small amount of slack to be left inside the fitting. I have a length of 0.75mm 3-core flex that I could use; given that 0.75mm flex is often used for pendant lights anyway on a domestic lighting circuit fused at 5A, would that be OK for the switch to fitting connection?
For further flexibility, what if I stripped the outer sheath off a section of the flex within the trunking, so that the separate cores could be doubled back on themselves to provide for extra slack (the minimum bend radius is too much if the outer sheath is left in place)?
The new fitting (LED with PIR etc) was clearly designed by someone trying to squeeze everything into the smallest possible space without any thought about how it might be installed in practice
There is an open-fronted black plastic rectangular box with a M16 knock-out in the back which will be screwed the wall. The actual lamp unit is fitted onto a open-backed metal box which is bolted over the plastic box like a cover.The T&E cable (a new length to replace the old) will come into the back almost directly behind the 4-way connector block and the cores will need to be bent at 90 degrees about 1/2" from their end in order to feed them into the screw terminals. The problem is that there is simple no room inside the unit, once assembled, to accommodate any slack in the T&E cores, so when the front is placed over the back the T&E is forced back through the wall. If I then bring it straight down into the trunking and into the switch, there is no way that the light can be disassembled for any reason without first removing the T&T tail from the light switch
One possibility seems to be to use 3-core flex instead of T&E, as a trial shows that the extra flexibility of the multi-stranded cores can allow for a small amount of slack to be left inside the fitting. I have a length of 0.75mm 3-core flex that I could use; given that 0.75mm flex is often used for pendant lights anyway on a domestic lighting circuit fused at 5A, would that be OK for the switch to fitting connection?
For further flexibility, what if I stripped the outer sheath off a section of the flex within the trunking, so that the separate cores could be doubled back on themselves to provide for extra slack (the minimum bend radius is too much if the outer sheath is left in place)?
