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1feralengineer t1_j2qbvvq wrote

Reply to comment by StoneTemplePilates in How many of these recessed lights can I use on a dimmer switch? by notscammed

The 600w rating is for a pure resistive load.

LEDs are a nonlinear load. They would fall in the capacitive category (the current leads the voltage by about a factor of about 0.8 full load/brightness). Dimming them can shift the power factor significantly (just because the wattage is reduced doesn't mean the current is reduced - especially peak currents that interplay with the semiconductors that do the heavy lifting of the dimmer).

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StoneTemplePilates t1_j2rhr67 wrote

>just because the wattage is reduced doesn't mean the current is reduced

How come? The LEDs still run on 120volts so if the wattage is reduced and the voltage is the same, then the current has to be lower. What am I missing?

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1feralengineer t1_j2rnsfk wrote

>What am I missing?

Power factor.

VA only equals watts in a purely resistive circuit (PF=1). In an AC circuit if the current sine wave leads the voltage sine wave (capacitive load), or the current sine wave follows the voltage sine wave (inductive load) the apparent power (VA) is higher than the actual power (W). PF=W/VA

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StoneTemplePilates t1_j2s3det wrote

I'm gonna need to do some googlage to understand this, but thanks for the explanation!

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