control with a combination of timer and photocell should be considered. The
designer should also consider using a backup power source with automatic
transfer switch for street and fence lighting.
In the vicinity of heliports operated by protective force personnel, or near
observatories, light glare should be minimized by selecting the proper fixture.
The installation of aviation warning lights on tall structures adjacent to heliports
should be considered.
Standby or emergency power systems should be used to support systems or
equipment components whose operating continuity is determined to be vital by
the design authority for protection of health, life, property, and safeguards and
Optional standby systems should be used to power production process
operations if the design authority determines that the process will become
unstable or that a severe monetary loss will result.
The design authority should specify the length of time the emergency power
source is required to maintain full operation of emergency loads. Such power
sources should include built-in features to facilitate operational testing on a
periodic basis to verify readiness.
The source of emergency power may be gasoline engines, batteries,
uninterruptible power supplies (UPSs), diesel engines, fuel cells, propane
engines, hydropower, or gas turbines as determined by capacity, starting duty,
and the life-cycle cost analysis. Steam turbine generators should be used if
steam is being produced for on-site processes.
In many facilities, there are critical loads that are sensitive to fluctuations in the
power supply. There are also loads that should be served continuously if the