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Posted

Hi
Does anyone know if its possible to stop a Beta Pack providing a low amp supply to Halogen fittings. Apparently its a feature to help prevent bulb damage but it stops LED replacement bulbs working properly?

IMG_0513.jpg

Posted

Hi,

Yes, it's called "preheat" and is a feature that allows halogen lamps to dim up smoothly from 0% - and conveniently also helps with avoiding thermal shock (the "bulb damage" you refer to).

Dimming LEDs with a conventional leading edge dimmer is a complex discussion and results are very dependent on the LED fixture.

The issue with LED fixtures is they contain some active electronics which needs current to operate. Trying to dim a "d0mestic" or similarly constructed LED lamp often gives disappointing results with dimming because of the electronics in the LED lamp housing. You will probably find the LED lamps flicker at low dimming percentages and will probably snap on/off ungracefully around 10-20%.

You dimmer has "houselights" scribbled on it. Maybe your venue have blindly removed the halogen lamps and plugged in LED lamps as a direct replacement. In which case you've come across the all too familiar situation, that whatever their purported green credentials, I'm afraid LED lamps are not a direct plug in replacement for such applications... If you want nicely dimmable LED houselights then you're potentially up for a wholesale redesign of your houselight installation.

To answer your original question, on the Betapack1, the preheat current is set on some potentiometers behind the back cover. Removing the back cover should only be done with the power to the dimmer isolated.

See the manual here:

https://www.zero88.com/storage/downloads/8970adda-b944-4fa8-b13b-8339d25f7571/Betapack-1-Manual.pdf

See page 2 left column and diagrams on page 3 - in your case "Hardwired" version.

Posted

That's great info and advice. Luckily the LED swap outs we've used so far have worked ok to an acceptable level of limitation. Wholesale redesign is not an option due to architectural design and esthetic requirements! I'll look into those  potentiometers. Thanks

Posted
1 minute ago, Ian Blair said:

Wholesale redesign is not an option due to architectural design and esthetic requirements!

Indeed 😉 and cost... It is a real pain.

That's great if your current LED lamps are behaving ok. Just beware when you need to replace them (because we all know they don't actually last for the claimed number of hours) then the replacements might not be so well behaved. If you are able to choose a branded type (e.g. Philips) then it's worth making a note of the model that seem to behave in your particular scenario. That doesn't of course mean that model will continue to be available in even a few months time. Such is the world we now live in...

Good luck!

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