Emerson ROC827 instruction manual Process

ROC827 Instruction Manual

General Calculation To calculate the power the ROC827 requires:

Process

1.Determine the kind and number of communication modules and the kind and number of expanded backplanes you are implementing. Enter those values in the Quantity Used column of Table 3-5.

2.Multiply the PTypical value by the Quantity Used. Enter the values in the Sub-Total column of Table 3-5. Perform this calculation for both the communications module and the LED.

3.Determine the kind and number of I/O modules you are implementing and complete Tables 3-6 through 3-15 for those modules. For each applicable I/O module:

a.Calculate the PTypical values and enter them in the PTypical columns of each table. Perform this calculation for the I/O modules, LEDs (if applicable), channels (if applicable), and any other devices.

b.Calculate the Duty Cycle value for each I/O module and each I/O channel (as applicable). Enter those values in the Duty Cycle column of Tables 3-6 through 3-15.

c.Multiply the PTypical values by the Quantity Used by the Duty Cycle on each applicable table. Enter those individual sub-totals in the Sub-Total column on each table and add the sub-totals to calculate the Total for the table.

4.Transfer the totals from Tables 3-6 through 3-15 to their respective lines in the Sub-Total column on Table 3-5.

5.Add the Sub-Total values for Tables 3-6 through 3-15. Enter that value in the Total for All Modules line on Table 3-5.

6.Add the value from the Total for ROC827 Base Unit to the Total for All Modules. Enter that result in the Total for ROC827 Base Unit and All Modules line.

7.Transfer the Other Devices total from Table 3-16 to its respective line in the Sub-Total column on Table 3-5.

8.Add the values from Total for ROC827 Base Unit, Total for All Modules, and the total for Other Devices. Enter that value in the Total for ROC827 Base Unit, All Modules, and Other Devices line.

9.Multiply the value in the Total for ROC827 Base Unit, Total for All Modules, and Other Devices by 0.25. Enter the result in the Power System Safety Factor (0.25) line.

Note: This value represents a safety factor to the power system to account for losses and other variables not factored into the power consumption calculations. This safety factor may vary depending on external influences. Adjust the factor value up or down accordingly.

Issued Mar-06 Power Connections 3-8