Dimmer switch and max 3 LV transformers query.

I was about to install a dimmer switch module (MK K4501 BSS BLV) to control a group of 4 low voltage halogen downlighters that are each supplied via their own individual ( 220 volt a/c to 12 volt DC) transformer.

But, the installation instructions says that the dimmer should not be used in a circuit with more than 3 transformers.

Can someone, who knows about electricity theory please explain the reasons behind this limitation. And, if more than 3 were connected, what would happen?

VT

Reply to
Vet Tech
Loading thread data ...

Real transformers as in lumps of iron with wire warpped around them have fairly hefty inrush currents, toridial (donut shaped) transformers commonly used in lighting applications have really big inrush currents. They also produce a spike when switched off. Either or both of these could kill the semiconductor switch in the dimmer.

Are your lighting transformers large and heavy (lumps of iron with wire) or small a light (electronic power supplies)? The latter won't have the inrush or spikes but they might object to being dimmed...

Reply to
Dave Liquorice

Almost certainly only applies if actual transformers - the switch on surge with these is vast and you usually have to half (or more) the dimmer rating with them. If you changed them (or even a couple) to electronic 'transformers' the restriction doesn't apply. One of these to supply 2 x

50 watt units costs under a tenner.
Reply to
Dave Plowman (News)

I will have to move some furniture and lift floorboards to check what type of transformer(s) I have. It may be a few days but I'll be back.

VT

Reply to
Vet Tech

Electronic types are normally installed through the hole for the fitting - to allow easy changing in event of a failure. Conventional transformers are usually too big for this.

Reply to
Dave Plowman (News)

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.