Hi,
I just purchased 2 GE dimmer 600W switches (GE Z-Wave Plus Switch and GE Zigbee. Now, I’m questioning how many LED bulbs I can run safely on these 600W dimmer switches. As for the bulbs, my kitchen runs 9 LED retrofit bulbs by FEIT. The description for these bulbs says 21W equivalent to 120W FEIT LED Link.
Using the same type of bulbs at 21W, 120W equivalent, how many can I safely run on these 600W switches?
Thank you!
Just sum up the actual wattage, not the “equivalent to brightness”.
Round up a bit.
So 600W ÷ 25W per bulb = 24 bulbs.
It doesn’t work that way because of the phenomenon of “inrush current.” Although LED bulbs run on very low wattage overall, when they start up there is a huge spike in current. For this reason you will find that every switch model will list its specifications in the user guide in two categories:
Resistant load, meaning incandescent and Halogens and
CFLs and LEDs.
https://www.etcconnect.com/Support/Articles/Inrush-Current-and-ETC-LED-Fixtures.aspx?LangType=1033
Also note that the total that the switch can handle will be reduced if you have broken off the side tabs, which act as heat sinks. This is true for both incandescents and LEDs.
Seriously, the exact specifications will be printed in the user guide for each individual model. You need to read the guide, find the specification, and follow it. Also note that the total that the switch can handle will be reduced if you have broken off the side tabs, which act as heat sinks.
So if you give us the model numbers for the switches that you are looking at, we can help you find the max loads for those, with the understanding that the max load for LEDs will be different—and much lower than the max load for incandescents. (Also, always round down, not up, when calculating max load for any electrical devices. In fact a lot of electricians will tell you to aim for 10% below the max load, but that’s a matter of personal preference.)
Let’s look at the newest GE in wall dimmer. Model 14294
The max load specs are 600w incandescent, 150w LEDs. But it drops if you have it in a double gang or triple gang set up where you had to break off the side tabs.
One more thing: wattage can vary quite a bit from One LED brand/model to another, so always check the specs on the bulb as well. A 60w incandescent Equivalent LED might be anywhere from 7W to 12 or 13 depending on the specific model.
In your case, for your 21 W LEDs with the Z wave 14294, you could safely support 7 of those specific bulbs with that specific switch.
To support 9, you would need the Leviton 1000 W equivalent switch, which can support up to 450 W of LEDs.
Extremely helpful @JDRoberts. Appreciate it.
A couple more questions if I may…
I was planning on swapping out the bulbs eventually to go 5000K so this is going to prompt me to do that. Based on what I’ve read, if sticking to the GE Model 14294 switch rated with a max load of 150w for LEDs, I just need to find an LED can light running under 16w per bulb, right?
The switch will sit in a 2 gang. How much of a reduced load should I factor in? Any ideas?
Thanks again!
It’s not the gang-size of the box but the amount of heat sink that is on the switch after you install it that matters. This is going to depend on what device is placed next to it. The heat sinks are the metal tabs on the left and right sides of the face of the switch. They are scored so that they can be bent and broken off.
You may or may not need to break off the heat sink tabs depending on what is next to the switch in the box. If you can fit the switch in the box and leave all the tabs, then the device will support the full capacity. If you have to break off the tabs on one side (because of the device next to it), then the capacity is reduced. You’d have to read the documentation to determine how much.
Yes to the 16w Per bulb if you have nine bulbs. Although some electricians would suggest a max of 15 W per bulb.
@Bry already gave you the answer on the double gang set up. 
Very helpful guys, thanks! I went ahead and purchased some 15W LED bulbs from Amazon. In case anyone was wondering I went with these.
Looks like a nice fixture! 
Actually the Leviton 600W switch/dimmer would still be fine as it support 300W LED load.