Custom Search
|
|
|
||
 MIL-HDBK-1012/1
5.2.2.5
Technical Load. The technical load is that portion of the
operational load required for electronic equipment and ancillary equipment,
including the lighting, air conditioning, and ventilation required for full
continuity of facility function. The operation of the technical load is
essential to the mission of the facility and normally requires emergency
power.
5.2.2.6
Noncritical Technical Load. The noncritical load is that portion
of the technical load not required for synchronous operation. This includes
nonsynchronous electronic equipment, test equipment, emergency lighting,
ventilation, and air conditioning for electronic equipment. The outage time
tolerance for specific facilities will vary. Refer to BESEP for specific
data.
5.2.2.7
Critical Technical Load. The critical technical load is that part
of the total technical load required for continuous synchronous operation of
electronic equipment. This includes any equipment that will malfunction
during a momentary power dropout and cause additional outage after power is
restored, as a result of the need to re-synchronize; loss of real time count
by master time sources; or loss of data in ADP systems.
Government-furnished UPS equipment shall serve all critical
technical loads. The BESEP will specify the loads to be served by the UFS as
well as the size of the system.
5.2.3
Electrical Power Characteristics. Unless otherwise stated in the
BESEP, the power characteristics normally will be as follows:
5.2.3.1
Voltage. Steady-state voltage variations shall not exceed plus or
minus ten percent of the nominal voltage level.
a) For sites with separate power plants, the preferred voltage is
480Y/277.
b) For other power sources, the preferred voltage is 208Y/120 for
loads less than or equal to 300 KVA and 480Y/277 for loads greater than 300
KVA.
5.2.3.2
Frequency. Steady-state frequency variations shall not exceed plus
or minus five percent of the nominal frequency. The preferred frequency is 60
hertz (Hz). If 60 hz is not available overseas, 50 hz is normally supplied.
5.2.3.3
Reliability. For technical load bus, reliability shall be 99.99
percent, exclusive of scheduled outages, which must not exceed a total of 53
minutes during any 1 year.
5.2.3.4
Dynamic or Transient Variation.
Limitations at the operational bus
are:
Voltage; Minus 15 percent, plus 10 percent.
a)
b) Frequency: Plus or minus 5 percent.
32
|
 
|
|
|
||
