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Chapter 12 Helpful information
On-line double conversion UPS units protect for these power issues - Power Failure, Power
Sage, Power Surge, Under voltage, Over voltage, Line noise, Switching transients, Frequency
variation, and Harmonic distortion.
Power failure
Under voltage
Switching transients Frequency variation
Emergency power systems
The key task of an emergency power system is to provide power during a prolonged supply
failure of the feed provided by the power utility company by using one or more power
generators. Such electrical power consuming devices can be ventilating or refrigeration or
cooling systems, fire-fighting lifts, emergency lighting but also UPS units.
Usually the emergency power generators are powered by internal combustion engines most of
which will use Diesel engines. The start up of these generators can take a considerable
amount of time. This delay time and some additional time reserve needs to be considered
when dimensioning a suitable on-line double-conversion UPS unit. This overall time frame
(delay and reserve time) that needs to be considered is also referred to as autonomy time.
Multi-line-fed power input
For error free operation it is essential that power supply system is always implemented as a
TN-S
earthing system. This is also relevant and important when multiple power sources are
used. In this respect power sources are not only all feeding points or transformers of the utility
power company, which supply electricity to the relevant power supply in question, but
particularly also any potential emergency power system and UPS units.
In case of multi-line-fed power input it has to be ensured that
between N and PE system are implemented in the same power supply system, irrespective to
whether the emergency power system is up and running or not.
In this set up all N conductors are connected to each other and the N network is only once
connected to the PE system.
6U Rack or Tower UPS RT8kVA and RT11kVA IUOMG
Power sag
Over voltage
Harmonic distortion
Power surge
Line noise
NO MULTIPLE CONNECTIONS
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