Blogger and Instapaper creator Marco Arment installed several Cree LED 60W-replacement bulbs in his home. After 3 months of running about an hour a day, he “found it [the bulb's glass cover] dangling there one morning, about to fall and shatter.” (Actually, the bulb wouldn’t shatter – its silicone coating is there specifically to prevent that. But still.)
Marco is happy with his Cree bulbs overall, but suggests you keep an eye on them.
Here’s what scares me: His last sentence is: “I was able to leave the glass off and swap this bulb with an intact one from an enclosed fixture.”
This is a horrible idea, and if the same thing should happen to your bulb, please don’t do it. The electronics in the Cree bulb are non-isolated: The cover serves to keep consumers away from the 120V ac line voltage. If you touch the electronics portion of the bulb with the cover off and the power on you risk electrocution.
The Cree bulb packaging specifically says don’t run it with the cover off. Yes, Marco says he has it in an enclosed fixture but that’s not good enough. If you want to get more into the technical issues of non-isolated vs. isolated bulbs, here’s a place to start. And here’s a tear-down of what’s inside the Cree bulb.
OK, we’ve covered the safety issue here. Next up: What about Cree bulb’s quality? I got in touch with Mike Watson, Cree VP of corporate marketing and asked him. His responses boiled down to this:
1. Home Depot has sold more Cree LED bulbs than all other LED bulbs combined, so anecdotally, Cree failures may seem to be more noticeable.
2. The failure rates for the Cree bulb are less than half the rate of any other light within its category (that is, 60 and 40W equivalent incandescents, other LED bulbs, and CFLs, etc) sold by Home Depot.
3. If any buyer experiences a problem with their Cree bulb, they should take it back to Home Depot for a replacement, no questions asked. If they prefer they can send it back to Cree.
4. You should never, ever operate a Cree bulb with its glass bulb cover off.
As an aside, I’ve purchased 8 Cree bulbs and had no quality issues.