Crosswords2 mins ago
Eco Halogen Bulbs
4 Answers
I have a light fitting with three 60W bulbs controlled with a dimmer switch. I want to exchange the bulbs with 42W eco halogen type bulbs. My bulb catalogue states that this type of bulb, if to be controlled with a dimmer switch, "additional fusing is required". Where within the lighting circuit would this additional fusing be positioned and what do I need to obtain to achieve it. Any advice would be gratefully received.
Answers
I too think that the manufacturer is covering their arse; but consider this:- A lighting circuit is normally protected by a 5A fuse/breaker – this allows for over 1000W on each lighting circuit. Should a fault occur, at 230V enough current will flow to operate the fuse. With a dimmer switch set at minimum, the voltage supplied to the bulb is likely to be less...
21:47 Sat 28th Dec 2013
Like The Builder, I am puzzled by this one and can only assume that this is yet another example of a manufacturer trying to cover his behind against the obscurest tendency toward litigation. I would not expect any problems changing from a 180W total load to 126W. But if you do want to install an additional fuse then it might be easiest to place a box beside your light/dimmer switch and install a face-plate-fuse unit in series with the lights. The only thing is that to make sense as some form of protection/safety, that fuse would have to be rated just above the total current draw on the lights which will be less than 1 ampere. The profusion of fuses in plugs throughout the country that are rated far above the anticipated current draw actually means that most such fuses are a waste of time. Mind you, the practice of fused plugs is uniquely British, nobody else seems to think it necessary.
I too think that the manufacturer is covering their arse; but consider this:-
A lighting circuit is normally protected by a 5A fuse/breaker – this allows for over 1000W on each lighting circuit. Should a fault occur, at 230V enough current will flow to operate the fuse. With a dimmer switch set at minimum, the voltage supplied to the bulb is likely to be less than 30V rms, it is far less certain that at this voltage, sufficient current will flow to operate the fuse.
With a continuous fault current at say 7A, who is to say what damage might result.
If you really want to add dedicated fusing to the dimmer, it would be simpler to fit an inline fuse within the dimmer switch – but be prepared to replace it each time a bulb blows (personally I would not bother). Most of my lights are on dimmers, with only the 5A breaker for protection.
A lighting circuit is normally protected by a 5A fuse/breaker – this allows for over 1000W on each lighting circuit. Should a fault occur, at 230V enough current will flow to operate the fuse. With a dimmer switch set at minimum, the voltage supplied to the bulb is likely to be less than 30V rms, it is far less certain that at this voltage, sufficient current will flow to operate the fuse.
With a continuous fault current at say 7A, who is to say what damage might result.
If you really want to add dedicated fusing to the dimmer, it would be simpler to fit an inline fuse within the dimmer switch – but be prepared to replace it each time a bulb blows (personally I would not bother). Most of my lights are on dimmers, with only the 5A breaker for protection.