Notes from server-room power design and build-out. A random brain-dump to try to remember some of this.
Computer and IT equipment can draw a lot of power. For mid-size server rooms and data center spaces, we can use 208v AC to power more equipment using less circuits from the building power room.
UPS battery back-up systems for bottom of rack are available in 6000VA and 5000VA capacities for 208v single phase power (standard for US, similar to joining two 110v circuits). Input plugs on these are usually NEMA L6-30P (30-amp 220v twist-lock). Output receptacles are usually L6-30R (female for L6-30P). 208v Power Distribution Units (PDU’s)
are used for the server-rack “power strips” which provide IEC 60320 style C13 and C19 receptacles (matching the male C14 and C20 plugs). These PDU’s do not use NEMA 5-15 or 5-20 receptacles to avoid confusion or destruction of equipment that may be compatible only with 110v power.
To save on rack space, many rack systems have a place to mount vertical “zero U” PDU’s. There are even tool-less models that snap right in. Standard horizontal PDU’s are available as well, but they take one or two U’s each. To get really fancy, each PDU can be ordered with extra features like “metered” to show power usage and “managed” to view and control over the network.
For pictures and more info on the types of plugs used with these UPS and PDU systems, check out the following articles:
- http://en.wikipedia.org/wiki/IEC_60320 (for C13, C14, C19, C20 and similar connectors)
- http://en.wikipedia.org/wiki/NEMA_connector (for 5-15, 5-20, L6-20, L6-30 and similar connectors)
For the random devices that do not support 208v power, a direct 110v circuit can be used, or a 208v to 110v transformer can be used (sometimes sold as a bundle with 208v UPS).