Take an average office turned into a server room. Many companies throw a 3 or 5 ton split air conditioner on a wall call the electrician and start loading the racks up with servers. Now a days the new server hardware can use all the power (and cooling) you have in probably one rack (think three loaded blade chassis with 16 servers each = 90 amps of 208v). The question is how much cooling can you afford?
For customers deploying 10 or more servers it is recommended to use the most efficient power delivery and structured wiring options.
Calculate you power and cooling needs with this spreadsheet. https://spreadsheets.google.com/ccc?key=tsfSMUDYsB-Ef2umhyORqvA
Using 3 phase power reduces the number of PDUs and “whips” required to power up large quantity of machines. The actual cables from the server to the PDU are the same and the power supplies still receive 1 phase 208v power. This is just a different and more efficient method of delivering the power to the servers.
You get higher densities with fewer wires to the electrical service panel with 3 phase power over single phase power. ServerTech has a great white paper on this topic here:
http://www.servertech.com/uploads/documents/0000/0236/3-Phase_Power_in_the_Data_Center.pdf
A 3 phase 30 amp 208V circuit can deliver 8.6 kw versus a 1 phase 30 amp 208V circuit which only delivers 4.99 kv.
Here is one of the more popular units…
http://www.servertech.com/products/smart-pdus/smart-pdu-cs-84vdd-vdy-3ph
Go with the 4 wire “Delta” configuration instead of the 5 wire “WYE” config. Wye power can distribute both 208 V and 120 V power from the same cabinet power distribution unit but requires an extra wire per PDU and is not needed in most datacenters. You will also be limiting the number of 208 volt power outlets with a WYE config PDU.
CS-24VD-L1530 – List $860.
CS-48VDD-L1530 – List $985.
CS-84VDD-L1530 – List $1,290.
You need to hire an electrician at $100 per hour x 4 hours plus parts.
Cheap fast switch with life time warranty:
24 ports NetGear GigE Unmanaged Switch – $260
http://www.netgear.com/Products/Switches/UnmanagedSwitches/JGS524.aspx
SuperGoose temp and humidity – $500
http://www.itwatchdogs.com/products_mon.shtml#wxg-2
Trendpoint power monitoring – direct $3085
http://www.trendpoint.com/TrendPointOne.html
48 port tie lines from each server rack to a central control rack cost about $2000 per rack
Sample power calculations (need to be adjusted) 24 amps x 208 volts = 5000 watts * 3 racks = 15000 watts = 51,113.088 with BTU/hour = 4.25 tons cooling (worst case)
3 Homaco M6 Square Hole 4 post Racks – $360.19 each
19-84-SSDA2732
http://www.homaco.com/equipfloorracks/adjustdual/m6serverrack.htm
OR-19-84-SSDA2732. 84″- M6 SERVER RACK. 84″- M6 SERVER RACK.
And you can get all the various power cables needed for 208vac
operation from quail.
http://www.quail.com/seriesPage.cfm?seriesID=9
