LV Halogen lights trip MCB

[adamr]

I've just replaced a fluorescent tube in the kitchen with a new low-voltage halogen track system. Now the MCB for the lighting circuit trips about three times a week when the new lights are switched on.

Although the new light is a higher wattage than the old one, I don't think it's overloading the circuit because it happens when there are only a couple of lights on in the house.

The MCB's always been quite sensitive - it always trips when a normal incandescent bulb blows, so I tried replacing the it with a new one - it's a 5A Wylex plug-in type, which directly fits in place of old wired fuses. Unfortunately the new one seems even more sensitive so I put the old one back.

Does anyone have any ideas about what I can do to sort out this annoying problem?

Thanks

Adam

 

[plugwash]

fit a 5A cartridge fuse unit

 

[adamr]

What about if I were to fit an inductive dimmer switch to the new track system?

Something like: http://www.tlc-direct.co.uk/Products/VL630LV.html

Would this prevent the surge at switchon and stop the MCB tripping? It seems like a backward step to fit a cartridge fuse, or is that truly the best remedy (would the fuse stay intact when a normal bulb blows for example?)

Thanks

Adam

 

[plugwash]

mcbs have a nasty habit of tripping on surges of high current but extremely short duration. this situation is unfortunately rather common in lighting.

fuses have a very different response and do not tend to blow in this situation

cartridge http://www.tlc-direct.co.uk/Products/WYC5.html
rewirable http://www.tlc-direct.co.uk/Products/WYR5.html (yes they swapped the pictures for the 5A and 30A rewirable carriers i've already sent an email)

 

[ban-all-sheds]

What about if I were to fit an inductive dimmer switch to the new track system?

Something like: http://www.tlc-direct.co.uk/Products/VL630LV.html[/QUOTE]
Is that the right sort of dimmer for your transformer, i.e. is it a wirewound one (toroidal or not)?

Assuming that the transformer is a dimmable type, then a dimmer, of the right type, might help, but I'm not sure how much of the starting surge on the secondary side translates into a surge on the primary. But it's worth a try.

A fuse is not necessarily a retrograde step - they are good for lighting circuits, as they don't blow when there's a surge due to a lamp failing. My lighting MCBs always trip when lamps blow, and when I replace the CU I'm either going to use Type Cs, or very possibly fuse carriers.

 

[adamr]

Thanks guys - cartridge fuse it is then.

Just out of interest - the transformer in the halogen track system is a big heavy cylindrical thing with lots of wound copper wire visible through the plastic sheathing - that's a toroidal, right? And therefore dimmable with the dimmer I mentioned in my last post? (just in case I decide in the future I want to be able to dim this light)

Thanks again

Adam

 

[ban-all-sheds]

Sounds like it.

It's probably wirewound anyroad, not electronic, which is the key thing. You ought to try and find out for sure though - contact the maker?