Technical Documentation

Power Consumption for a DC-Powered SRX5600 Services Gateway

Note: If you plan to operate a maximally configured DC-powered services gateway, we recommend that you provision 58 A  (32 A per feed) @ –48 VDC for the system.

If you do not plan to provision 58 A  (32 A per feed) @ –48 VDC for the system, you can use the information in Table 1 and Table 2 to calculate the power consumption @ –48 VDC, and thermal output for various hardware configurations.

Table 1 lists the power requirements for base DC-powered devices operating under typical voltage conditions.

Table 1: DC-Powered Base System Requirements

DC Power Supply Configuration

Power Requirement (Watts)

Current Requirement (Amps @ –48 VDC)

Nonredundant configuration includes two DC power supplies, midplane, craft interface, and the fan tray (running at normal speed)

135 W (approximate)

2.8 A (approximate)

Redundant configuration includes four DC power supplies, midplane, craft interface, and the fan tray (running at normal speed)

180 W (approximate)

3.8 A (approximate)

Table 2 lists the power requirements for various hardware components when the services gateway is operating under typical voltage conditions.

Table 2: Component Power Requirements

Component

Power Requirement (Watts)

Current Requirement (Amps @ –48 VDC)

Fan tray (full speed) – Fan tray (normal speed)

110 W – 80 W =30 W

0.6 A

SCB

150 W

3.1 A

Routing Engine

90 W

1.9 A

IOC—Generalized typical value

312 W

6.5 A

IOC—Generalized maximum value

365 W

7.6 A

SPC—Generalized typical value

213 W

4.4 A

SPC—Generalized maximum value

351 W

7.3 A

Use the information in Table 1 and Table 2 to calculate power consumption for various hardware configurations, input current from a different source voltage, and thermal output, as shown in the following examples. These examples use generalized values per IOC. Typical power consumption for DC-powered devices:

  • Minimum DC-powered configuration:
    Base device (nonredundant) + 1 SCB + 1 Routing Engine + 1 IOC + 1 SPC—Generalized typical value =
    2.8 A + 3.1 A + 1.9 A + 6.5 A +4.4 A = 18.7 A @ –48 VDC =898 W
  • Maximum DC-powered configuration:
    Base device (redundant) + fan tray at full speed + 2 SCBs + 1 Routing Engine + 5 IOCs + 1 SPC—Generalized maximum value =
    3.8 A + 0.6 A + 2(3.1) A + 1.9 A + 5(7.6 A) + 7.3 A=
    3.8 A + 0.6 A + 6.2 A + 1.9 A + 38 A + 7.3 A= 57.8 A @ –48 VDC = 2774 W DC
  • Input current from a DC source other than –48 VDC (based on maximum configuration; applies to DC power supply only):
    (–54 VDC input) * (input current X) = (–48 VDC input) * (input current Y)
    54 * X = 48 * 57.8 A
    X = (48 * 57.8 A)/54 = 51.4 A
  • Thermal output for maximally configured DC-powered services gateway:
    Watts DC * 3.41= BTU/hr
    2774 W * 3.41 = 9459 BTU/hr

Published: 2009-11-03