We have had several requests for information about the general electrical requirements for minicomputer-based library systems from libraries planning new buildings or building renovations. The libraries are attempting to anticipate future needs rather than seeking to implement a specific automated system.
The following requirements are common to many of the mini-based systems and should, with only minor modifications, be suitable for all but the largest systems.
- a. CPU (Central Processing Unit)
Voltage 120 or 208 +/- 15%, 3 phase, 30 amp dedicated circuit, heat output 12,000 BTU per hour.
- b. Disk Drives
Voltage 120 or 208 +/- 10-15%), 3 phase, 15 or 30 amp dedicated circuit per drive; heat output 6,000 BTU per hour each.
- c. Tape Drives
Voltage 115 or 230 +/- 10%), single phase, 2.6 amps to 5 amps on shared circuit; heat output 1,400 BTU per hour.
- d. System Console
Voltage 110 or 220 (±10%), single phase, 7.5 amps on shared circuit; heat output 2,400 BTU per hour.
Ideally all of this equipment would be contained in a single room of 250-300 square feet. The roan should be secured so that only authorized system operators will have access. These figures should be used for preliminary planning only as the specific requirements vary from vendor to vendor. One of the biggest hurdles may be arranging for 3 phase electrical power. Many rural and suburban area power companies may require written justification several months in advance of bringing this capability to the library.
Typically the cost for revamping the electrical and air conditioning systems of a building to adequately accommodate a mini is $5,000-7,000.
