prior to bid opening. Equipment shall be supported by a service
organization that is, in the opinion of the Contracting Officer, reasonably
convenient to the site.
2.2
LOAD PROFILE
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NOTE: Determine power factor requirements. Edit
Table as required.
The UPS capacity is specified in kW. kVA varies
with power factor. A typical 60 kW UPS delivers 60
kW and 75 kVA at 0.8 power factor (lagging); 60 kW
and 66.7 kVA at 0.9 power factor; and 60 kW and 60
kVA at 1.0 power factor.
The UPS may exhibit load interface problems with
certain types of ac load. The items which present
the greatest problems are motors, transformers,
electric discharge lighting, and SCR and mag-amp
power supplies. Problems with these loads are
caused by either load nonlinearity or inrush
currents required for their operation. The
Contractor will be better able to accommodate
specific applications if well-defined load data is
available. Factors to consider include:
a. Type of load - Data processing equipment, main
frame chilled water pump, etc.
b. Size of load - kVA or kW rating, horsepower,
voltage and amperage of load.
c. Switching pattern - Unswitched; cycled daily;
cycled hourly; operated by thermostat; building
management system control.
d. Transient characteristics - Specify inrush
current magnitude and duration (i.e., 15 times
steady state rms current for 1/4 cycle for electric
discharge lighting); range of power factor variation
(i.e., as low as 0.4 lagging for electric discharge
lighting); voltage dip.
e. Steady-state characteristics - specify range of
power factor, particularly if outside the 0.8
lagging to 1.0 range. UPS derating is normally
required for the unusual circumstance of loads at
leading power factor. Consult vendors if in doubt.
In some cases a demand factor might be applicable to
the load.
f. Special factors - Harmonic characteristics;
factors that vary with temperature or age. The
designer may vary the load profile format.
Estimated or approximated load data may be used in
the absence of exact information but should be so
identified.
SECTION 16265A
Page 15
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