cu change, fault fixing

[tom1]

changed a cu not long back, no probs except on house lights circuit.

no cpc, but only class2 and 3 fittings.

problem is 2 of the fittings are permently live in the bayonet, also perm live in the switch and the switch wire is also live but not 240.

pendants are painted and baked. new carpets and not willing to have upheaval.

any idears.

thanks

 

[Andy™]

permantely live would usually be a switch thats not switching (unless its been wired wrong)

 

[tom1]

must be wired wrong, close the switch and you get 240 across the pins, open the switch and stays live on one pin. so i thought it was switched through the neutral , but if so then why would it be live in the switch?

 

[a1spark]

Sounds to me like some sort of series wiring there Tom . could poss be a s/L & N cross connection somewhere. Are the light dimmed in any places.....is there evidence of any recently installed light fittings....try testing to earth also[{ with long lead]...I hope its loop in wiring at the roses mate

 

[tom1]

does not seam to be any dimmed lights, no cpc on the circuit

the garage is the most recent thats in twin, but cpc is just goes to nothing.

dont think they will have me pull the house to bits but were do i stand on the cert

 

[a1spark]

Hi Tom . , Yes I know you did state there was no cpc, when i suggested testing to earth -with a long lead I meant testing the voltage at the switch and at the light between each conductor and earth at the C.U.

 

[tom1]

Hi Tom . , Yes I know you did state there was no cpc, when i suggested testing to earth -with a long lead I meant testing the voltage at the switch and at the light between each conductor and earth at the C.U.

i see thanks

 

[a1spark]

If all lights and switches are mettallic you can enter it as a departure on the cert ,if you qualify it with the statement that it is line with the recommendations of the ESC best practice guide.. no ideal though. AS far as the lighting wiring being defective ,I think that needs sorting out .

 

[Andy™]

must be wired wrong, close the switch and you get 240 across the pins, open the switch and stays live on one pin. so i thought it was switched through the neutral , but if so then why would it be live in the switch?

missing/dodgy neutral somewhere?

 

[tom1]

Sounds to me like some sort of series wiring there Tom . could poss be a s/L & N cross connection somewhere. Are the light dimmed in any places.....is there evidence of any recently installed light fittings....try testing to earth also[{ with long lead]...I hope its loop in wiring at the roses mate

cant get the fittings off unles i smash them, i managed to get one of the others off and its not looped at the rose.

the guy changed a dodgy one by cutting the flex and wireing an new bayonet.

if they dont go for remedials should i just note it on the cert?

 

[a1spark]

Hi Tom. its a tricky one cos youve changed the C.U . If the affected ones are pendants would you think you could swap the lampholders for the type with an in line switch. thereby providing the function of switching the lamp ,albeit at high level, then noting on the cert in the comments box. Pre install survey & Inspect & test would have saved all the hassle though

 

[tom1]

Hi Tom. its a tricky one cos youve changed the C.U . If the affected ones are pendants would you think you could swap the lampholders for the type with an in line switch. thereby providing the function of switching the lamp ,albeit at high level, then noting on the cert in the comments box. Pre install survey & Inspect & test would have saved all the hassle though

true but how far do you go befor doing any work.

he had no earth and no rcd, so needed sorting

not bad idear about the switching though

 

[Zeespark]

Can you not put a dust sheet down and use a sharp knife to cut away the gunk and loosen the accessories?

AndyGuinness

 

[Chr!s]

must be wired wrong, close the switch and you get 240 across the pins, open the switch and stays live on one pin. so i thought it was switched through the neutral , but if so then why would it be live in the switch?

Tom it will be live in the switch

If live is taken straight to a lamp then looped down to the switch, when the switch is open 230 volts will be present.

When the switch is closed then there will be a volt drop across the Lamp so 230 wont then be present.

regards chris

 

[Andy™]

Hi Tom. its a tricky one cos youve changed the C.U . If the affected ones are pendants would you think you could swap the lampholders for the type with an in line switch. thereby providing the function of switching the lamp ,albeit at high level, then noting on the cert in the comments box. Pre install survey & Inspect & test would have saved all the hassle though

i cannot see any possible way that changing a CU can make a light now stay on permenent

 

[tom1]

lets see if i can clarifiy.

the pins inside the bayonet. 1 is perm live at 240v, when the switch is closed you get 240 across the pins.

in the switch, 1 core is perm live at 240. the other is also perm live

 

[a1spark]

[quote name='Andy

 

[Chr!s]

the pins inside the bayonet. 1 is perm live at 240v, when the switch is closed you get 240 across the pins

If there is a perm live to bayonet then for it to operate you must be switching the neutral

 

[tom1]

the pins inside the bayonet. 1 is perm live at 240v, when the switch is closed you get 240 across the pinsIf there is a perm live to bayonet then for it to operate you must be switching the neutral

thats what i thought but if the neutral is switched then why is it perm live in the switch

 

[Chr!s]

in the switch, 1 core is perm live at 240. the other is also perm live

Are u using a multi meter for these tests?

When testing for these voltages, is the switch open or closed?

what type of switch is iteg dimmer?

For the 240 120 volts what reference are u using?

regards chris