Flickering LED Fault cause found, I think.

[GBDamo]

Have had a recall on an office LED swap out.

Some of the panel LEDs flicker for a fraction of a second very randomly.

The panels are fed from four three phase DBs, and all the boards and all the phases have aircon(AC) supplies fed from them. Now, some of the AC units are inverted but some of them are not.

My thinking is that the compressors in the older non-inverted AC units are possibly on their last legs and as a result are using higher than design current on start up. This is causing a dip in voltage on the circuit, as LED have no latency this voltage drop is enough that the LED power down for a fraction of a second. This can be proved by measuring the inrush current and comparing this to the design spec.

Can anyone recommend a reasonably priced clamp meter that will reliably and accurately measure inrush/start up current.

My options if the AC is causing this is to recommend replacement, preferably, or possibly fit hard start kits to the offending units.

Does this diagnosis sound reasonable? any other thoughts or possibilities.

 

[GBDamo]

GBDamo - good morning. How are you getting on with this problem please?

Not too well,, spent a lovely night inrush testing all the AC units to find all working within design parameters. Could not get a light to flicker even when cycling multiple AC units.

It was the fact we didn’t see a flicker all night that has led to the next line of investigation which is to look into the incoming supply.