High frequency inverter won’t drive LED PIR flood lamps

[Sverige]

I’m using a 5000W Mensela IT-1 inverter which is running various low power loads around my house quite successfully, but for reasons I don’t understand, it just won’t light my LED security floodlights which are activated via a PIR detector and look like the photo below. They are just 8.5W each and I have three on a circuit, and when triggered by walking in front of them in darkness I see the LEDs faintly pulsing with a frequency of around 1Hz or so.

So what could it be about my inverter’s output which the LED lamps don‘t like, and could it be corrected somehow? I will get out there later today and measure the voltage reaching the lamps, but other outdoor lighting (led light bulbs) on the same circuit light up fine, so I doubt it’s anything as simple as a lack of volts.

EDIT: problem is now solved! It was my own silly fault for making assumptions about cable core colours designating function. I had connected my supply from inverter to the wrong “live” which was not actually making it all the way to the lamps! Doh…

 

[Bud Martin]

Does it work properly if you test it on power from utility?
"They are just 8.5W each and I have three on a circuit, and when triggered by walking in front of them in darkness I see the LEDs faintly pulsing with a frequency of around 1Hz or so."
Can you manually force it on instead of using the detector?

 

[Sverige]

Does it work properly if you test it on power from utility?
"They are just 8.5W each and I have three on a circuit, and when triggered by walking in front of them in darkness I see the LEDs faintly pulsing with a frequency of around 1Hz or so."
Can you manually force it on instead of using the detector?

Well I’ve not yet switched them back onto mains, but they’ve run faultlessly for 3 years on mains prior to my switching the circuit over to solar, so I’m quite sure it’s something about the 230V AC from the inverter which they are not liking.


These lamps can’t be forced on, as the detector is integral to them.

 

[Bud Martin]

Well I’ve not yet switched them back onto mains, but they’ve run faultlessly for 3 years on mains prior to my switching the circuit over to solar, so I’m quite sure it’s something about the 230V AC from the inverter which they are not liking.


These lamps can’t be forced on, as the detector is integral to them.

May be the AC output of the inverter has too much noise due to poor EMI filter. Do you have any audio amplify that you run it off the inverter and see if you can hear noise coming through the speaker?

 

[Sverige]

Yeah, could be something like that. I don’t have an amp and speakers to test with, but wonder about adding a small polyester capacitor in parallel with the supply close to the PIR lamps. I’m sure I have one which arrived as an LED lamp antiflicker capacitor with a RF controlled light switch I ordered recently. Hopefully can’t do any harm just to add it to circuit temporarily to see if it helps.

 

[Rednecktek]

Just to throw it out there, a lot of inverters have a "Low Power" or "Power Saving" mode where they don't provide any AC unless there is a minimum amount of load, like 50w or so. When in "Power Saving" it checks the load every so often to see if it needs to turn on which may be your 1Hz flicker.

If your inverter is doing that the 26w those lights call for if they all try to kick on might be below that minimum threshold to turn the AC on.

 

[Sverige]

Just to throw it out there, a lot of inverters have a "Low Power" or "Power Saving" mode where they don't provide any AC unless there is a minimum amount of load, like 50w or so. When in "Power Saving" it checks the load every so often to see if it needs to turn on which may be your 1Hz flicker.

If your inverter is doing that the 26w those lights call for if they all try to kick on might be below that minimum threshold to turn the AC on.

Thanks, but the inverter is definitely on and providing power, as it’s supplying my TV, heating circulation pump and all the other outdoor lighting which is on the same circuit as the PIR floodlights.

 

[Sverige]

Problem is now solved! It was my own silly fault for making assumptions about cable core colours designating function. I had connected my supply from inverter to the wrong “live” which was not actually making it all the way to the lamps! Seems like the flashing I saw was coming thru the neutral connection. Doh…

Thanks for everyone’s suggestions.

 

[Rednecktek]

Win! Always gotta love an easy fix.