Checking Whether The Output Of A Power Supply Unit Is Sufficient - Siemens HiPath 3000 Service Manual

power_calc.fm
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).
Caution
7
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.
Procedure
Proceed as follows to identify the secondary power requirement of a system:
1. Determine secondary power requirement at the 5-V output
5 V power requirement of the boards/components used
= secondary power requirement at the 5-V output
2. Determine secondary power requirement at the –48-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
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.
D-14
P31003-H3550-S403-4-7620, 02/05
HiPath 3000 V5.0, HiPath 5000 V5.0, Service Manual