LED Wattage

[Little Bill]

Can you trust the LED wattage listed on the light to figure lighting load?
Example 150W LED 600W equivalent
150W/120V=1.25A

I'm wanting to put 6 of these lights on a 15A circuit. It's fine if the wattage is correct and I don't have to consider in-rush. I put up thousands of smaller wattage recessed LED with no problem. These are high bay and just wanted to be sure 15A would be enough.

 

[hillbilly1]

I put in some 220 watt led strip fixtures, sized my circuits accordingly, then found out the pulled quite a bit less than what they were rated at. And this was Lithonia fixtures, not some Amazon China fixtures. So you can’t put much stock in what the manufacturer says.

 

[hillbilly1]

(They were 220 watt equivalent, but the actual LED wattage was below what they stated, I think they had the drivers tuned down, they were dimmable, but I did not use the dimming function, tried to find the actual wattage again, but I lost that info somewhere)

 

[Joethemechanic]

Yeah I was wondering how accurate the manufacturers specs were on those LEDs. I have some high bays out and wanted to switch to all LED while I'm up there. I'd hate to go through all the aggravation and end up with a dim shop.

 

[ptonsparky]

Can you trust the LED wattage listed on the light to figure lighting load?
Example 150W LED 600W equivalent
150W/120V=1.25A

I'm wanting to put 6 of these lights on a 15A circuit. It's fine if the wattage is correct and I don't have to consider in-rush. I put up thousands of smaller wattage recessed LED with no problem. These are high bay and just wanted to be sure 15A would be enough.

FWIW, I would trust it.

 

[Besoeker3]

Most of ours are 6W. In our living room we have three 11W units. These are very bright - my wife sows.

 

[winnie]

I would trust the numbers to be correct for the steady state.

But with respect to inrush you really have no data. It all depends on how well the driver circuit is designed to limit inrush.

FWIW incandescent lamps also have a rather significant (10x) inrush, so I wouldn't stress too much about 7.5A of LEDs on a 15A circuit.

If the lamps were switched separately than I wouldn't worry at all.

-Jon

 

[synchro]

It's interesting that many dimmers have a significantly lower maximum wattage rating for LED bulbs vs. incandescent. For example, the one at the link below is rated 250W for LED and 600W for incandescent. This may be because of the very fast risetime on the output of forward phase dimmers using SCRs. That would cause current spikes through capacitors in the LED bulb's internal driver circuits. And the dimmer's electronics would be limited on the peak current that it can supply during those spikes.

https://assets.lutron.com/a/documents/369810.pdf

I assume that if the high-bays are dimmable they have a 0-10V control, and so the limitation above for LED bulbs would not be relevant.

 

[Joethemechanic]

I assume that if the high-bays are dimmable they have a 0-10V control, and so the limitation above for LED bulbs would not be relevant.

Nothing dimmable in my shop lol, pure 1980's technology. Sixteen 400 watt metal halide high bays on 8 circuits. I should have changed them all to LED 8 years ago when I bought the place and nothing was in the way. Instead I just re-lamped them all with new bulbs the previous owner left in a storage room. If I'm going to go to LEDs I probably should think about dimmers too

 

[Little Bill]

It's interesting that many dimmers have a significantly lower maximum wattage rating for LED bulbs vs. incandescent. For example, the one at the link below is rated 250W for LED and 600W for incandescent. This may be because of the very fast risetime on the output of forward phase dimmers using SCRs. That would cause current spikes through capacitors in the LED bulb's internal driver circuits. And the dimmer's electronics would be limited on the peak current that it can supply during those spikes.

https://assets.lutron.com/a/documents/369810.pdf

I assume that if the high-bays are dimmable they have a 0-10V control, and so the limitation above for LED bulbs would not be relevant.

Thinking of the reduction for dimmers is what got me thinking about the wattage being true. The lights in question are dimmable with 0-10 but I won't be using that.
I will have 4 rows of 6 lights, each row on a 15A circuit.