Page 242 - Uninterruptible Power Supplies

Notes on Systems Installation
240 Chapter Nine

Wind Turbine

Tower

PV Array (Optional)

DC
Source
Center
Wind
Charge PV Charge DC - AC
Controller Controller Inverter Engine
Generator
(Optional)
System Controls
Not Shown

Battery Bank
DC 120/240 VAC
Loads Loads
Figure 9.5

Local advice should be obtained regarding both the availability and
reliability of wind and solar energy and a cautious attitude taken as
regards to periods of absence of either source!
Airport runway lighting is clearly a critical load and the most advanced
specification calls for no outage to be longer than 1 to 2 s (Category 3 ).
However, in many cases UPS units are in use.
There are instances where the use of standby emergency lighting
systems is precluded due to the very nature of the lamp load. We refer
to high-pressure discharge lamps, the inner envelope of which, when
quiescent, has a very low gas pressure and it is relatively easy to strike
a discharge through the low gas pressure tube. This gas pressure
builds up when the lamp is running and full light output is attained at

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