Circuit tripping after fitting new light

[Baxman]

I have just replaced a single bulb light with a mains transformer supplier multilight (20 x 10 watt bulbs), a heavy copper wound transformer rather than a small lightweight one. The light works but trips the mcb sporadically when it is switched on. Think the issue is to do with the circuit board and I will need to replace a B for a C switch. I had an issue with this light in a previous house and fixed it by putting a dimmer switch on to give a soft start. Done this here and it has helped but still getting trips. What can I do to resolve? I am not qualified spark but reasonably handy, how difficult is above job and if I am correct should I just get spark in? Rough cost?

 

[jj4091]

If the rcd trips it is not a loading issue,more likely insulation breaking down intermitently.If you had the problem in a previous house then the best & easist way to resolve it is to bin the fitting & buy a new one.

 

[ban-all-sheds]

I will need to replace a B for a C switch.

I take it you've checked that the EFLI of the circuit will allow a Type C to be used?

 

[Baxman]

Thanks for suggestions. Not sure so think I will buzz a professional to take a look

 

[Taylortwocities]

Here's a guide

Untitled

• Taylortwocities
• 27 Mar 2010
• 43

Do you really mean

circuit board

or consumer unit?
and
What is tripping, RCD or MCB?

 

[Baxman]

It's the mcb that's tripping but as I say not every time it's sporadic, sometimes fine sometimes trips. Think the tripping is less frequent now that I have fitted a dimmer - not sure if that gives any clues.

 

[jj4091]

It's the mcb that's tripping but as I say not every time it's sporadic, sometimes fine sometimes trips. Think the tripping is less frequent now that I have fitted a dimmer - not sure if that gives any clues.

You did not say that before you editted your post. What changed your mind?

 

[bernardgreen]

a heavy copper wound transformer

These have a high in rush current and this is the reason it is tripping at switch on.

The resistance of the primary is very low and at the instant that voltage is applied the current is very high until the magnetic flux can develop and create a back voltage that reduces the current. After that the AC impedence of the coil can control the current,

Only by using a zero crossing point switch can the in rush current be eliminated. A zero crossing point switch closes when the AC mains voltage is close to zero so there is a much reduced in rush current.


The dimmer reduces the inrush current as it switches closer to the zero crossing point