Lighting protection

[tomodo]

Hi everyone, i was replacing some fluorescent light fittings the other day and noticed that the internal wiring is 0.75mm. These lights are wired in 2.5mm and are on a 16 amp breaker which is sufficient protection for the supplys going to the lights but not for the internal wiring of the lights. Is this allowed? Or should every light have its own fused spur? Is there any regulations on this? Cheers

 

[Knobhead]

There's plenty of regulations, far more than most electricians think are needed.

After looking through your previous post I'd suggest you bought a copy of BS7671

 

[Guest77]

Hi everyone, i was replacing some fluorescent light fittings the other day and noticed that the internal wiring is 0.75mm. These lights are wired in 2.5mm and are on a 16 amp breaker which is sufficient protection for the supplys going to the lights but not for the internal wiring of the lights. Is this allowed? Or should every light have its own fused spur? Is there any regulations on this? Cheers

Where are you thinking of putting it? bolting the box to the side of the light :smilielol5:

 

[Farmelectrics]

internal fuse maybe

 

[Farmelectrics]

have a good read of what lighting ballasts do ??????

 

[ImpededLoop]

With due respect, the OP has their occupation listed as "trainee".

The protective device is there to protect the electrical installation rather then the light fittings. The manufacturers instructions for the light fittings may specify a maximum rating for the protective device.

As farmelectrics says, some light fittings do have internal fuses.

 

[Farmelectrics]

of the top of my head the ballast increases the voltage for a short period for the lamps to strike and also controls the flow of current to the lamps

 

[Guest77]

With due respect, the OP has their occupation listed as "trainee".

The protective device is there to protect the electrical installation rather then the light fittings. The manufacturers instructions for the light fittings may specify a maximum rating for the protective device.

As farmelectrics says, some light fittings do have internal fuses.

They are only safe in the Trainee area, if their name is not in purple then we have no idea they are training.

 

[tomodo]

The manufacturer does not state a maximum mcb size. I have ordered some internal fuses. I realise they have a ballast but it doesnt change the fact that theres a 0.75mm cable connected to a 2.5mm cable 16a supply surely in the case of a fault the 0.75mm will be damaged before the mcb trips?

 

[Guest77]

Most modern lights have a 3 amp fuse internally fella, if you are training please click on the link in my signature and join the trainee forum.

 

[tomodo]

I qualified about a year ago need to change profile. These are modern lights? And no internal fuse ? Thanks for all the replys.

 

[Guest77]

I qualified about a year ago need to change profile. These are modern lights? And no internal fuse ? Thanks for all the replys.

Must be cheap lights then :biggrin: I cannot remember the last time I fitted a decent light with no 3 amp fuse in it.

 

[davesparks]

The manufacturer does not state a maximum mcb size. I have ordered some internal fuses. I realise they have a ballast but it doesnt change the fact that theres a 0.75mm cable connected to a 2.5mm cable 16a supply surely in the case of a fault the 0.75mm will be damaged before the mcb trips?

Don't worry about the internal wiring of the fittings, it only needs to be sized for the current that fitting requires.
For a start the ballast in a flourescent fitting is there to limit the current.

 

[Knobhead]

Or burn out, which I what they seem to like doing.