Halogen spots

[Horatio]

Can anyone help? I recently moved the garden workshop and wanted to improve the lighting, I removed the old fluorscent(fed from a 5 amp supply off the consumer unit) and fitted some halogens. First the 5 amp fuse blew, and the main board circuit breakers tripped. I checked all connections and tried again, same!! changed the cabling, same!! Several trys later still the same. After running out of 5 amp fuse wire, I fitted 15 amp, now the fuse wire is OK at the consumer unit is OK but the main fuseboard circuit breaker still trips.

I put back the fluorescent, via the same wiring and switch no problem, I fitted a standard bulb, no problem. What is going on??

 

[IanDB]

What's the total wattage of the spoltlights that you're using?

 

[ban-all-sheds]

Good grief...

After running out of 5 amp fuse wire, I fitted 15 amp, now the fuse wire is OK at the consumer unit is OK but the main fuseboard circuit breaker still trips.

THAT IS VERY WRONG - YOU MUST NEVER USE HIGHER RATED FUSEWIRE!

I put back the fluorescent, via the same wiring and switch no problem, I fitted a standard bulb, no problem. What is going on??

By the sounds of it, unless you're trying to fit several kW of lighting, you've got a faulty light fitting. You say that the main fuseboard circuit breaker trips - do you mean the individual MCB feeding the garage unit, or the RCD protecting the whole thing?

 

[IanDB]

unless you're trying to fit several kW of lighting

Gotta ask though!

 

[Tom.]

The fuse should always be of a lower value than the cable its connected to. For instance, putting a 13A fuse on a 5A cable for an appliance means that the cable could melt before the fuse (and cause a fire).

 

[Horatio]

Wow!!

OK - lesson learnt with the fuse wire - should have stopped work when I ran out, frustration got the better I guess.

Have now got more correctly rated fuse wire and will fit later, also bought some low voltage, mini lamps at 25 watts each lamp, 2 off.

Originals were, 50 watt (2 off), this is the thing I didn't understand, 100watts total seemed barely more than a standard light bulb.

Originally when the fuse in the consumer unit went the whole circuit breaker unit tripped. Later with fuse intact It was the individual circuit breaker that would trip, indicated as "sockets" on the board.

It isn't unusual that when bulbs blow that the RCB unit trips, I reset it change the bulb and away we go.

 

[ban-all-sheds]

What happens when you have the transformer for the lights connected up, but no bulbs in? If that trips the circuit breaker then you're pretty much guaranteed that the transformer is faulty. Is it a new one?

 

[Horatio]

All done! - new spots/transformer and all is OK - but I still can't figure out why the original spots (normal voltage) would keep blowing??