Power Consumption for a DC-Powered MX240 Router
We recommend that you provision at least 33.3 A @ –48 VDC for each input.
If you do not plan to provision at least 33.3 A @ –48 VDC per input, you can use the information in Table 1 and Table 2 to calculate the power consumption @ –48 VDC and thermal output for your hardware configuration.
For high capacity power supplies, we recommend that you provision at least 75 A @ –48 VDC (input switch set to 1) for each input.
If you do not plan to provision at least 75 A @ –48 VDC per input, you can use the information in Table 1 and Table 2 to calculate the power consumption @ –48 VDC and thermal output for your hardware configuration.
Table 1 lists the power requirements for base DC-powered routers operating under typical voltage conditions and includes nonredundant and redundant power supply configurations. The base DC-powered router includes the midplane, craft interface, and fan tray running at normal speed.
Table 1: DC-Powered Base Router Power Requirements
DC Power Supply Configuration | Power Requirement (Watts) | Current Requirement (Amps @ –48 VDC) |
|---|---|---|
One DC power supply (nonredundant configuration) | 50 W (approximate) | 1.04 A (approximate) |
Two DC power supplies (redundant configuration) | 66 W (approximate) | 1.38 A (approximate) |
| High-Capacity Power Supplies | ||
One high capacity DC power supply (non-redundant configuration) | 90 W | 1.9 A (approximate) |
Two high capacity DC power supplies (redundant configuration) | 106 W (approximate) | 2.2 A (approximate) |
Table 2 lists the power requirements for various hardware components when the router is operating under typical voltage conditions.
Table 2: Component Power Requirements
Component | Power Requirement (Watts) | Current Requirement (Amps @ –48 VDC) |
|---|---|---|
SCB | 150 W | 3.1 A |
Routing Engine | 90 W | 1.9 A |
Fan tray (full speed) – Fan tray (normal speed) | 70 W – 50 W = 20 W | 0.4 A |
High capacity fan tray | 85 | 1.8 A |
DPC—Generalized typical value | 312 W | 6.5 A |
DPC—Generalized maximum value | 365 W | 7.6 A |
FPC2 (without PICs) | 110 W | 2.3 A |
FPC3 (without PICs) | 180 W | 3.8 A |
MPC (fixed configuration) | 440 W | 9.17 A |
MPC (without MICs) | 294 W | 6.13 A |
For exact DPC, MPC, MIC, and PIC power requirements, see the MX Series 3D Universal Edge Routers Line Card Guide.
These examples show how to calculate typical power consumption for your DC-powered router configuration. The examples use generalized values for DPCs.
Typical power consumption for DC-powered routers:
- Minimum DC-powered configuration:Base router (with fan tray at normal speed and one power supply) + 1 SCB + 1 Routing Engine + 1 DPC =1.04 A + 3.1 A + 1.9 A + 6.5 A = 12.5 A @ –48 VDC = 600 W DC
- Maximum DC-powered configuration with one host subsystem
and a third DPC in the multifunction slot:Base router and two power supplies + fan tray at full speed + 1 SCB + 1 Routing Engine + 3 DPCs =1.38 A + 0.4 A + 3.1 A + 1.9 A + 3(7.6 A) =
1.38 A + 0.4 A + 3.1 A + 1.9 A + 22.8 A =
29.58 A @ –48 VDC = 1,420 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 * 29.58 AX = 48 * 29.58 A/54 = 26.3 A
- Example of calculating system thermal output:Watts DC * 3.41 = BTU/hr1,420 * 3.41 = 4,842 BTU/hr
