Intel II manual Current Usage, Calculating Power Usage, Worksheet, Calculating DC Power Usage

Current Usage

As an overall current usage limitation on the power supply, do not exceed a combined power output of 167 watts for the +5 V and +3.3 V outputs.

Calculating Power Usage

The total combined wattage for the system configuration must be less than 300 watts. Use the two worksheets in this section to calculate the total used by your system. For current and voltage requirements of add-in boards and peripherals, see your vendor documents.

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 10. Power Usage Worksheet 1

Current (maximum) at voltage level:

Device +3.3 V +5 V –5 V +12 V –12 V

Boards, processors, and memory (get totals from your board manual)

SCSI backplane

Front panel board

3.5-inch diskette drive

CD-ROM drive

Second 5.25-inch device

1st hot-swap hard drive

2nd hot-swap hard drive

3rd hot-swap hard drive

4th hot-swap hard drive

5th hot-swap hard drive

1st IDE hard drive

2nd IDE hard drive

Cooling fan 1, 92 mm				0.4 A
Cooling fan 2, 92 mm				0.4 A
Cooling fan 3, 92 mm				0.4 A
Total Current
Maximum Ratings (for comparison)	16.0 A	26.0 A	0.25 A	10.0 A	0.5 A

Equipment Log and Worksheets 59