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SCC010020020 PWM short circuit fault

I have 50 of these PWM installed for street light applications.

when the sun drops and PV voltage drops the PWM set on “L” activates the load output, this is connected to a 150w pure sine wave inverter. A 50w 220v AC LED is running off the inverter.


On several the load switches off flashing fast indicating short circuit.

But it is intermittent.


If it does trigger short circuit, it won’t recover that night, it may work correctly next day, but may fault again days later.


Any ideas



Streetlight
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Mark avatar image
Mark answered ·

The invertor has capacitors in it that would draw a huge 'spike' of current when they are discharged and power is first connected - similar to a short circuit fault.

If you are running the inverter directly from the MPPT load connection there i's not a heap you can do except to use the load connector to switch a suitable relay / contactor instead or use some kind of separate time delay and 'pre-charge' circuit through a resistor.

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Correct.


And if the inverter has a (remote) on/off, you could wire that (with a relay) to the load output, so the capacitors stay charged and in that case you don't need a pre-charge circuit.