electrical knowledge for data center geeks?
I'm in the process of purchasing a data center UPS at work. Looking at an APC SmartUPS VT currently. I was looking at something larger from Liebert, but the vendor wanted $18k for the install, more than the cost of the hardware itself, and I have a hard time justifying $18k for what should be a couple days worth of work. In the process of all this, has been a lot of attention to power. I'm at a junction right now, I basically don't have enough power for the UPS I'm looking at, but the UPS is larger than I need, as we plan on building a new data center in the not too distant future. This has lead me to an electrical code question. In the end, I'm probably going to have our electrical contractor do the work over a vendor, because despite not having the confidence of the vendors experience with their own equipment, electrical contractors generally have names, like John, or Bob, and I can chat with them for five minutes respect their work from the conversation. That and they do a good job without charging $4k/hr or whatever the vendor's project costs come out to be. But yeah. I like small shops. If I can't find someone with a first name to talk to who can spend ten minutes explaining the engineering of the situation to me, I'm not going to trust their judgement and I'm going to find someone else. Of course, I'm certainly not going to try to do it myself. I'll worry about vendor inter-operable LACP, they can worry about harmonics. It's what we both get paid for.
But still, I've been communicating with our electrical contractor and a couple vendors all along, but I'm not really satisfied until I understand the mechanics, or perhaps the electrics, of the situation. Tonight I posted my question on an electricians forum. It's currently up for debate as to if I'm allowed to ask questions there, as they have a policy against answering "how-to" questions to avoid laymen killing themselves, doing illegal electrical work, etc. Hopefully they side with me. As I got thinking about their choice though, I realized how much I think about electricity. Sure, I've got all these outlets in the ceiling of my data center, all I really have to do is plug my PDU's from my racks in and not worry about it, right? I'm IT, that's facilities. Well, there's no such thing as facilities in my company, and I previously come from even smaller companies where the concept of departments didn't even exist, so I might be a semi-rare case here. But I think about electricity a lot. I wonder what the current and peak current of my racks and PDUs are, ensuring I'm not only not overloading a breaker, but evenly balanced across phases. Then when the UPS comes into the picture, I further get to worry about the load on the UPS, run times, etc. All this leads to spending a lot of time figuring out how 120V single phase power relates to 208V three phase power, the difference between KVA and KW for UPS sizing, and why the hell my datacenter was built with NEMA 5-20 plugs instead of something rugged and locking like an L5-30.
Maybe that's why there are specialized vendors out there getting $18k for an install. But people I work for seem to want me to know whats going on, and more importantly, I don't sleep at night if I don't get it anyways. So, other admin folk, how does power affect your daily life (besides windpocalypse 2k6 and the fact that casey lives in the sticks)?
But still, I've been communicating with our electrical contractor and a couple vendors all along, but I'm not really satisfied until I understand the mechanics, or perhaps the electrics, of the situation. Tonight I posted my question on an electricians forum. It's currently up for debate as to if I'm allowed to ask questions there, as they have a policy against answering "how-to" questions to avoid laymen killing themselves, doing illegal electrical work, etc. Hopefully they side with me. As I got thinking about their choice though, I realized how much I think about electricity. Sure, I've got all these outlets in the ceiling of my data center, all I really have to do is plug my PDU's from my racks in and not worry about it, right? I'm IT, that's facilities. Well, there's no such thing as facilities in my company, and I previously come from even smaller companies where the concept of departments didn't even exist, so I might be a semi-rare case here. But I think about electricity a lot. I wonder what the current and peak current of my racks and PDUs are, ensuring I'm not only not overloading a breaker, but evenly balanced across phases. Then when the UPS comes into the picture, I further get to worry about the load on the UPS, run times, etc. All this leads to spending a lot of time figuring out how 120V single phase power relates to 208V three phase power, the difference between KVA and KW for UPS sizing, and why the hell my datacenter was built with NEMA 5-20 plugs instead of something rugged and locking like an L5-30.
Maybe that's why there are specialized vendors out there getting $18k for an install. But people I work for seem to want me to know whats going on, and more importantly, I don't sleep at night if I don't get it anyways. So, other admin folk, how does power affect your daily life (besides windpocalypse 2k6 and the fact that casey lives in the sticks)?
posted by btm at 8:29 PM
9 comments
