And the rating of this wire should be what?

[attractivebrunette]

Installing 10 x ceiling downlights, halogen 50 watts each.

This is the original cable coming out of the ceiling.

Untitled

• attractivebrunette
• 27 Nov 2010
• 3

What rating of cable do I need to daisy chain the lights together? I imagine the total load will be 10 x 50 watts = 500 watts.
The voltage is 240 thus I imagine amps will be 2.08?

What size and rating of cable / flex will I need?

 

[holmslaw]

..

 

[bernardgreen]

It is not as simple as connecting the lamps to where the original lamp was connected.

With 500 watts of halogen all being switched on at the same time you might need to look at more than just cable size. In the short time between a lamp being switched on and it becoming white hot it will draw a lot more current than it does when white hot. At least 5 times as much and possibly 15 times as much. This in-rush current can trip some fast acting MCBs.

 

[attractivebrunette]

What do you mean the connection point on the fitting? The fitting on the lamp? It's a typical fire-rated spotlight lamp.

Untitled

• attractivebrunette
• 5 Feb 2011
• 1

Bernard, so if you're saying the lamps can draw 15 times as much current initially, what rating cable / flex will I need?

 

[ricicle]

TROLL ALERT !

 

[ban-all-sheds]

Installing 10 x ceiling downlights, halogen 50 watts each.

That's sheer madness.

 

[ricicle]

Installing 10 x ceiling downlights, halogen 50 watts each.

That's sheer madness.

Congrats on your post count !

 

[bernardgreen]

Bernard, so if you're saying the lamps can draw 15 times as much current initially, what rating cable / flex will I need?

1mm or 1.5mm will carry the short duration in-rush current safely. You may find your MCB trips sometimes when you turn the lights on. The switch may wear out sooner than expected.

The fire proofing of the ceiling may be affected.

If you fit these in the ceiling of a flat then there will be problems if you affect the fire resistance of the fire barrier between you flat and the flat above you.

 

[attractivebrunette]

Hi Bernard, thanks for your help

I have some 1mm flex which should do the job fine, but I might change it to 1.5mm just to be on the safe side.

If the MCB keeps tripping, what can an electrician do to solve it? Can a different rating of circuit breaker be fitted or something?

Re-the ceiling of the flat, I imagine as the lamps are fire-rated it shouldn't cause too much of a problem with the fire-resistance of the ceiling?

 

[kai]

If you have a suspended false plasterboard ceiling, (Like what I have) with the actual real ceiling above it, you can safely install downlighters on it, as they won't be penetrating the real ceiling above it (which is the fire barrier for the flat above etc).

 

[SgtTrojan]

TROLL ALERT !

http://www.youtube.com/results?search_query=trololololololololololo&aq=3