power_calc.fm
P31003-H3560-S403-54-7620, 09/05
HiPath 3000 V6.0, HiPath 5000 V6.0, Provisional Service Manual
D-15
Identifying System Power Requirements
Checking Whether the Output of a Power Supply Unit is Sufficient
D.8
Checking Whether the Output of a Power Supply Unit is Sufficient
Apart from the secondary power requirements, the power output must also be checked to en-
sure that the maximum possible output of the system’s power supply unit is sufficient. For this,
the power requirement on the 5-V output format and on the –48-V output format must be ex-
amined separately.
A separate calculation must be performed for every HiPath 3750 and HiPath 3700 system cab-
inet (in other words for every UPSM).
Procedure
Proceed as follows to identify the secondary power requirement of a system:
1.
Determine secondary power requirement at the 5-V output
2.
Determine secondary power requirement at the –48-V output
Using the specified values, check whether the total power requirement exceeds the maximum
possible output of the power supply unit at the 5-V output or at the –48-V output. If this is the
case, you have the following options:
●
HiPath 3800
The number of LUNA2 power supply units can be increased.
●
HiPath 3750 and HiPath 3700 with UPSM
For multiple cabinet systems, the distribution of boards on the system cabinets can be op-
timized. Please observe the configuration notes in Section 4.3.6.
7
Caution
To guarantee smooth system operation, the nominal output of the power supply unit
at the 5-V output and at the –48-V output must be greater than the respective sec-
ondary power requirement.
5 V power requirement of the boards/components used
=
secondary power requirement at the 5-V output
–48 V power requirement of the boards/components used
+
power requirement of connected workpoint clients (analog and digital telephones),
key modules and adapters
=
secondary power requirement at the –48-V output