Filter
Top Products
Index 141
Worksheet, Calculating DC Power Usage
1. List the current for each board and device in the appropriate voltage level column.
2. Add the currents in each column. Then go to the next worksheet.
Table 12. Power Usage Worksheet 1
Current (maximum) at voltage level:
Device +3.3 V +5 V –5 V +12 V –12 V
Server board 1.0 A 8.0 A 0.1 A 1.1 A 0.4 A
Primary Processor
Secondary Processor (if present)
Terminator card, if no second
processor
1.6 A
Memory (four 128 MB DIMMs) 1.8 A 0.3 A
PCI slot 1
PCI slot 2
1
st
3.5-inch hard disk drive
2
nd
3.5-inch hard disk drive
3
rd
3.5-inch hard disk drive
4
th
3.5-inch hard disk drive
3.5-inch diskette drive
CD-ROM drive
Cooling fan 1 .300
Cooling fan 2 .300
Total Current
Worksheet, Total Combined Power Used by the System
1. From the previous worksheet, enter the total current for each column.
2. Multiply the voltage by the total current to get the total wattage for each voltage level.
3. Add the total wattage for each voltage level to arrive at a total combined power usage on the
power supply.
Table 13. Power Usage Worksheet 2
Voltage level and total current
(V X A = W)
Total Watts
for each voltage level
(+3.3 V) X (______ A) ________ W
(+5 V) X (______ A) ________ W
(–5 V) X (______ A) ________ W
(+12 V) X (______ A) ________ W
(–12 V) X (______ A) ________ W
Total Combined Wattage ________ W