Rob Bunger of APC discusses different voltage options for data centers, including alternating current (AC) options to increase power distribution efficiency.
Read the full transcript from this video below:
APC exec discusses data center voltage options
Mark Fontecchio: Hi, I'm Mark Fontecchio. I'm a reporter with TechTarget. With me today is Rob Bunger. He is the director of Enterprise and Systems Business Development in North America for APC. We are going to talk to Rob a little bit today about the different voltage options in the data center. So, Rob maybe you could just start by giving us a little background.
Rob Bunger: Sure. It's a popular topic right now. When first talk spawned upon talking about DC in the data centers, but now various AC voltage options. When you look at a typical data center, when you come out from the street voltage, it's typically transformed down to 480 which would then flow through your UPS system and then from that point go to PDUs on the four down to 208/120 volt to go to your servers. Traditionally most IT folks have been plugging right into 120 volts. Even despite the fact that all their servers can run anywhere from 100 volts up to 250 volts. More and more popular nowadays and we definitely see it from what our customers are asking for, is running the servers at 208 volts. This has an advantage to be able to run more power down the same size wires and it's also slightly more efficient from a power supply perspective in the servers. The server manufacturers basically say that the higher the input AC voltage inside the server you get a little bit more efficiency out of that power supply.
Mark Fontecchio: So can you explain, Rob, how you get more efficiency out of running a higher voltage into your server?
Rob Bunger: Within the server power supply and I can't get into too much detail because that's not my area of expertise. But typically, again, as you get a higher voltage, that means there are less current for the same amount of power. When you have less current that's less [I square R] losses and basically the losses are proportional to the square of the current. So again, if you get the voltage up there are less losses. Again, there tends to be, if you think about the whole power distribution chain, there is a little bit less copper involved, again as you are able to raise that voltage basically to deliver the same amount of power downstream.
Mark Fontecchio: Okay, now what about beyond 208 volts?
Rob Bunger: Yeah, there is a lot of talk about basically adopting European or the rest of the world's voltage system inside the data center to save money in various different ways. As an example, in Europe their power distribution skips a step. Instead of going street voltage to 480 and then 480 to 208, they basically go from street voltage down to 400 volts. The 400 volt three phase is what they run throughout their whole facility and then their single phase voltage is 230 volts. So all of the same servers that we have here run over in Europe at 230 volts. What this does is all of the UPS systems run 400 volt three phase and then when you get to the rack you split out the single phase and there are no transformers or PDUs. So you save already in the power distribution change. There are no transformers so you gain a couple of points there. You also gain a little bit, again, in the size of the cabling that you have to deliver the same amount of power to the servers.
Mark Fontecchio: So, if we were to do that in the US would it require a whole restructuring of the electrical infrastructure?
Rob Bunger: Typically no. Obviously any products that you have to use here are generally going to have to be all UL listed to do that. But the plugs that are used to go from say the outlet strip or rack PDU to the server are the IEC, either C13s or C19s, which are already being used in the US with the 208 voltage distribution. So when you look at late servers or any other boxes they are typically already being fed from 208 single phase. This would just take it up to 230 volt single phase.
Mark Fontecchio: Okay, great. Well, Rob thanks a lot for talking to us.
Rob Bunger: Thank you.