help and advice please on lighting

[jon jordan]

hi guys i need a bit of help

got a job today loft fire
bathroom lights ( cought fire ) 50w dichroic lamps burnt saw dust ..

BATHROOM LIGHTING ON ITS OWN CIRCUIT IN A 6AMP MCB
ALONG WITH ALL UPSTAIRS LIGHTING ON ANOTHER CIRUCIT IN SAME MCB
4 X ENERGY SAVING LAMPS ON UPSTAIRS LIGHTING CIRCUIT
4 X 35W DICHROIC LV LAMPS IN BATHROOM.

any way refiited new cabling which was burnt out and new fire proof fitting x4
and new trannys.

put power back on ( ready for this )

we have power at mcb 230v
we have power at light switch IN BATHROOM 230v switches off when pull cord engaged
we have 12v at trannys
but lights not working ( lamps all ok )

also all upstairs lighting aswll not working
i checked stairs lightswitch testing gave 12v ( fluke t100 tester)


thanks jon
arggghhhhhh ( please help is it something ive done )

 

[coxy84]

sounds like you've transformed the upstairs lights, did you use a jb somewhere? or the 12v at the switch is just a inductive load. and you've got a bad termination some where.

 

[tonys]

If you carried out an R1+R2 you would know whether or not you have a complete circuit and what about the RCD for the special location?

 

[cagedanimal2010]

are you testing line to cpc? have you checked for a neutral? light switch giving you 12v what are you testing?

danny

 

[jase]

you say both circuits in mcb, what about the neutrals and earths?

 

[jon jordan]

all cable in cu are in where they should be. ( note i didint touch the other lights ie stairs, bedrooms )

rcd power the 6 amp mcb so bathroom ok

on the stais light switch i took plate off wall and tested the common to cpc and l2 ( 2 x black cables ) to cpc. 12v reading on t100.

going to g back today with fluke 1652 didnt take yesterday oops .

 

[cagedanimal2010]

so common to cpc and l2 to cpc you were getting 12v?

 

[jon jordan]

so common to cpc and l2 to cpc you were getting 12v?

yeah mate what i cant get my head around is that ive not touched that circuit ? so why would it have 12v as no trannys are on that cabling.

only where the 2 circuit meet is at the cu in the same mcb.

 

[nickblake]

If you have done an R1R2 test at the lights then you'll have confirmed continuity of the L and CPC you have also said there is 12v out of the transformer , it does sound to me as there is a loose or disconnected neutral as your getting a 12 at the switch and the cpc could be open circuit check all your connections again just incase there a broken wire especially at the junction boxes for that job in a loft you should realy be using one of the new 17th down lighter jbs or a wago box and connectors , so just re check connections and redo the R1R2

Nick

 

[jon jordan]

sorry nick i may have confused you

the 12v is at the stairs light switch not the bathroom pull cord.

the bathroom circuit all test ok 230v where they should be 12v at tx but no lights on ( thanks lli check connection again as it was dark at 8pm last night.) thanks jon

 

[LukeD]

I always make sure i hoover if possible the light fittings and around he hole etc. Seen so many situations where rubbish etc is far to close to the rear of the bulbs. Did a lot of light 2 years ago and we used chopped large stack pipe to make sure the insulation never got close to the bulbs. That stuff shifts around a lot ! Even dropping 12v's has me covered in dust most times !

 

[jon jordan]

hehehehehehe what a pleb i am sodding got there this morning when into cu in daylight and found the sodding neutral out happy days

thanks for all your help guys