Torodial transformer

[daza]

Hello,

We have fitted a torodial transformer rated at 300W. This is running a track system of 5x 50W 12v lamps.

It is on a lighting circuit protected by a 10A type C MCB.

The problem we have is that it has blown up 2x 400W dimmer switches to date, the second one lasting only a few turns on & off.

We have contacted the tech dept of the manufacturer / supplier & they say a 400W dimmer should be ok.

I am aware of the high start up current. Should we be looking to install a 1000w dimmer switch or change to a normal 10A rated switch?

The light was supplied by the customer. What do you recomend? have you come across a similar problem?

Many thanks in advance.

 

[kme]

It "should" be okay; but obviously isn`t.

Is the dimmer "suitable" for controlling LV lamps? some don`t like it !

You`ve obviously got the dimmer in the primary circuit, yes? (sorry.)

erm....... No, never had that problem. Maybe someone else has.

Good luck

KME

 

[ProDave]

What sort of dimmer?

Is it the sort that has a pushbutton on / off switch (2 way), or the sort that clicks off when you rotate it fully anti clockwise (1 way)

My guess is it's the pushbutton sort, and turning it on, with the dimmer at or near full brightness, and the high inrush current of the torroidal tx is killing the dimmer.

If you swapped it for the sort that clicks off at fully anti clockwise, then every time you turn it on, it starts up at low brightness and as you then turn it up you are in effect giving it a soft start and I'll bet that sort survives. No good though if you have 2 way switching on that circuit.

A 1KW dimmer would no doubt be better, but they are usually in a 2G plate.

 

[Evans Electric]

I think ProDave might be right there, TBH.

Toroidals do have a high inrush current, dump the dimmer switch they are a PITA .

 

[daza]

many thanks

we are using a push button sort maybe worth changing to click on as turned type as sujested.

A 2G plate is not a problem as it is a 2G now.

Yes dimmer is installed in primary circuit & is suitable for SELV. secondary side links straight to track.

 

[mikep]

Hi Daza,

You say you have 5 x 50w lamps then why not go for a soft start Electronic tranny like this one, only