Why are my leds flickering?

[Lardos86]

I bought new led fixtures to install (6) on a circuit with nothing else on it but a few more leds. I’ve got them on a Lutron dimmer switch. They flicker pretty regularly. I’ve tried swapping all the bulbs out, and also changed the dimmer switch. It doesn’t matter what brightness I have them at, they still flicker. Does any one have ANY idea of what step I should take next?

 

[telectrix]

is the dimmer trailing edge? if it's leading edge, could cause problems. and what form of drivers do you have for the LEDs?

 

[Lardos86]

I’m assuming it’s training edge? It’s a newer dimmer. This may be a stupid question, but is there a minimum wattage spec for each individual dimmer that can cause this? I would say I’m only using about 50 watts max for the whole circuit.
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Trailing

 

[telectrix]

dimmers generally have a min, and max, wattage stamped on them. if you dimmer is , say, min 60 watts, then 50 watts load is not enough.

 

[Lardos86]

Called Lutron, and they said the two dimmers I have is compatible with the wattage and lights that are in there.

 

[telectrix]

think it might be best now. to consult a local electrician. several US members on here, dunno if any are in your locale.

 

[Lardos86]

10-4 thanks alot

 

[marconi]

The LED lamps flicker because the current through them 'flickers' on and off when they are supplied by a bi-directional current as is derived from an ac powered dimmer and LEDs have no persistence or after-glow. If the LED lamps were powered by a constant current direct current they would not be turning on and off but the brightness might swell up or fade downwards - good quality constant current drivers have regulators to stop this.

There is a myriad of reasons why the LED driver current in your situation is flickering. But it is late so I will not go into them much except to say that there are often 'stability' issues when a particular dimmer (even though trailing edge) because of its technology may be unstable when connected with a particular LED (and its technology) or a number of LEDs on the same circuit. As an example only - inside the dimmer is a thyristor or triac which require a minimum 'holding current' to remain conducting which LED lamps, because of their relatively low power consumption, do not draw - so as the sine wave unfolds over time the thy/tri turns off before 'it should do' - no current - no light - flicker.

A common cure is to add a pure resistance load in parallel with the LED(s) which alters the voltage/current waveforms in way which causes stability. In the example I gave it would be to exceed the minimum holding current to ensure the thy/tri did not turn off early.

In the UK one can buy these load resistors which are wired in parallel with an LED or string of LEDs. How many load resistors you require is trial and error.

No doubt the US produces something similar. As a pure resistor there would be no harm in buying a UK one and wiring it in circuit, since our mains voltage is higher than yours for lighting anyway. Note well the cautions about the safe placement of these devices so that the heat they generate can be dissipated. The TLC description says this component by Danler needs an earth/ground connection but the Danler installation instructions make no reference to this so I reckon this is an error by TLC.

Resistive Load Device 10w - https://www.tlc-direct.co.uk/Products/DNRESLOAD.html?source=adwords&ad_position=&ad_id=315107931576&placement=&kw=&network=u&matchtype=&ad_type=&product_id=DNRESLOAD&product_partition_id=297072075353&version=finalurl_v3&gclid=Cj0KCQjwuZDtBRDvARIsAPXFx3B91X8Qps78tGp1CYXN2Fgzi9ra2OThaWsYLf3BwyiacDW8bk8SjPYaAglHEALw_wcB

 

[Lardos86]

So basically if I had something off that same switch that had constant current, it probably wouldn’t flicker?
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Thanks a lot for the help!

 

[marconi]

By George I think you've got it. Yes you are on the right lines.

 

[Lardos86]

Good deal. I’ll look at some resistors. Thank you