Identify Emergency Power Sources

Dad, what's your best advice for some commercial lighting? My best advice for commercial lighting is to realize that there's always an emergency source behind it. Emergency. There's an emergency power source behind commercial lighting. In other words, engineers design buildings so that you can get out in an emergency. Okay? So, one of my biggest tips I can give you is make sure that you've isolated the circuit that's feeding the light fixtures when you're working on them. >> Okay? >> And determine where that emergency egress power is coming from. That must be there. >> Okay? >> Now, it's either going to come from a life safety generator >> or it's going to come from a battery like this. This looks like a battery. Oh, this looks like a ballast, but it's a battery. This This is a battery. >> It's a battery. So, if you notice in some commercial lighting, some of the fixtures are going to have >> a charge button. >> Okay. Just like that. >> Yes. And it's going to be illuminated, right? >> And what this does is this will this always has power, constant power to it. >> Mhm. And often times, even when you turn