66 C120-H007-05EN
CHAPTER 6 Power Supply Facilities
6.1.2 Calculating the power required
For the purpose of selecting the kind of power supply facilities required, calculate the
total power requirement of every unit in the system by consulting the relevant
Installation Planning Manual.
6.1.3 Calculating the rush current
The rush current calculation assists with selecting a UPS. Calculate the rush current in
the power-on sequence by consulting the documentation for each component. The
case that more than one device may turn on at the same time should also be
considered.
If the UPS is started up rapidly, the UPS startup could occur as rush current flows
from the server system line filter and before the server system power controller begins
to properly supply power to the server system. In this case, the UPS may detect
overcurrent. Try to use an UPS that allows for a slow startup.
Table 6.1 Input power requirement
Item Requirement
Input voltage Number of phases Abroad
Single-phase two-wire 100 V, 110 V, 115 V, 120 V
Single-phase two-wire 200 V, 208 V, 220 V, 230 V, 240 V
Three-phase three-wire 200 V, 208 V,220 V, 230 V, 240 V
Three-phase four-wire 380 V, 400 V, 415 V neutral conductor
connected to ground
Voltage regulation From +10% to -10% of the input voltage or less
Instantaneous input voltage
variation
+15% to -20% of the input voltage or less in 0.5 second or
shorter
Instantaneous input
interruption
1/2 cycle or less (10 ms or less at 50 Hz, 8.3 ms or less at 60 Hz)
Input frequency 50 Hz or 60 Hz
Frequency regulation +2% to -4% of the input frequency
Input voltage imbalance 5% or less (three-phase input)
Voltage waveform distortion 10% or less
Power capacitance Depends on each unit specifications
Rush current Depends on each unit specifications