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running a fluorescent strip light from spur?

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running a fluorescent strip light from spur?

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running a fluorescent strip light from spur? 1 year ago #7340

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hi everybody. Can somebody please tell me if it is ok to install a double fluorescent strip light and run it direct from a fused switch spur from my radial power circuit.
the circuit comes into the garage and only supplies one double socket ( in 2.5 tae) its on a 20a mcb.
ive then run 2.5 from the socket to a fused switch (5amp fuse) then 1.5 tae straight in to the live , neutral and earth on the light missing out the switch.
when i test the lamp with the switch on i have power going to each end of the light fitting but the bulbs wont come on????? the light is brand new so i dont suspect there's a problem with the starters or the unit itself.
Have i made a crucial error in the wiring arrangement??

Re: running a fluorescent strip light from spur? 1 year ago #7347

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That is the way I would wire it. Nothing wrong with what you relate.

I would first replace lamp with something simple to ensure no mistakes. Like a bulb in bulb holder.

If it works then we look at the florescent unit. There are a number of variations the main is induction or inverter ballast. Inverter or electronic it's just a case of follow instructions on case.

With the older inverter some have a starter some don't. But the problem is they will not start if voltage is low and use over power rating is voltage is high.

When the voltage moved from 240 to 230 some old units failed to start and imports from Europe use over rated power.

Tubes are not all the same either easy to fit wrong diameter which causes starting problems. Check what is written on ballast.

There are different starters the electronic type some times will not work when two tubes are in series.

Re: running a fluorescent strip light from spur? 1 year ago #7350

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thanks. i replaced the light with a new fitting and it works perfectly. i guess the other light must have been faulty. All good now though.

i'm running swa down to a summer house to power a mini consumer unit with rcd. this is to power a couple of sockets and a light.

if there is room in the existing ccu at the house can i wire the swa into a fuse here?

Or will i have to henley block the tails and terminate the swa differently?

Could you tell me what would be normal practise??

Re: running a fluorescent strip light from spur? 1 year ago #7351

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A henley block by-passes the consumer unit so only the DNO will protect anything coming off it. So it would need to feed a second consumer unit so unless you have run out of space in orignal consumer unit then one would not consider using a henley block.

Many consumer units are plastic and will warp with SWA connected to them and it's a real pain with banjo washers to connect the earth without misshaping box. I would normally use a metal box often a metal clad back box with a blank lid or even a FCU to swap from a non SWA to SWA cable.

As to "can i wire" well yes you can but to comply with law likely more expensive than getting a scheme registered electrician to do the work for you. LABC charges are silly.

In the main power to outbuildings will when I do it have a number of FCU's but no extra consumer units. In the main 13A is enough and a FCU in house (with 13A fuse) or RCD FCU if not already RCD protected and a socket and switched FCU with 3A fuse for lights so it doubles as light switch is normally ample. Often taken from CU but as a spur from ring MCB.

Keep it simple. Once over 13A is required much changes and also distance and earth arrangements have to be considered. Of course I will test everything with loop impedance tester, RCD tester, and insulation tester but at around £75 to hire many DIY people don't bother. But with Part P now no option if staying within the law so add around £200 to price to DIY within the law to cover hire charges and LABC charges.

Re: running a fluorescent strip light from spur? 1 year ago #7355

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hi. idecided to run 2.5 from the new mini CU ( containing 32ma RCD, 16a mcb (2 double sockets) ( 6a mcb for 0ne light and switch)
back to the board and terminate the swa in a metal back box with plain lid.
the box sits about 6 inches above the main CCU.
the length of the swa cable run is approximately 10m to the summer house.

would you suggest choc blocking the swa tails in the metal inclosure to some 2.5 tae? one of the 3 cores will be used as an earth as well as the armour sheath on the swa but would the earth be big enough in the tae? or should i use a bigger cable.

i am wiring in to a spare 20a mcb onthe consumer unit which is rcd protected also.
Does this sound safe?

i have an electrician friend coming over after ive installed to check and test by the way.

Re: running a fluorescent strip light from spur? 1 year ago #7356

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I wish I could work out what can and what can't be done without testing and working out the sums but that's not the case.

I hate choc block can't really see why one would want to use it I would use din rail and proper terminals but I am industrial and I know house electricians traditionally have used connector strip so I suppose you may as well do the same.

But guessing and crossing fingers hoping it will all pass is not really the way to do it. I would test before I start then any problems I am aware of before I am faced with the question do I turn it one when I know it does not comply?

What I am saying your taking a chance. It all is good the inspector will issue you with the paperwork and alls good. But if the loop impedance is too high it's easy for him he just says fix it. For you your faced with renewing with thicker cable. i.e. "Do it again and do it properly" so I would get it tested before and after.
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