Technical Documentation
M320 Power Requirements
 | Note: To allow for future growth so that you can operate the router in any hardware configuration without upgrading the power infrastructure, we recommend that you provision at least 48 A @ –48 VDC (nominal) for each DC power supply. If you do not plan to provision at least 48 A @ –48 VDC (nominal) per input, you can use the information in Table 1 to calculate the typical power consumption @ –48 VDC and typical thermal output for your hardware configuration. |
Table 1 lists the power requirements for various hardware components when the router is operating under typical voltage conditions. Generalized values are listed for PICs. For power requirements for specific PICs, see the M320 Multiservice Edge Router PIC Guide.
Table 1: Component Power Requirements
Component | Power Requirement (Watts) | Current Requirement (Amps @ –48 VDC) |
|---|---|---|
Base system, not including FPCs and PICs (includes four SIBs, one host subsystem, two power supplies, cooling system running at normal speed, and craft interface) | 450 W (approximate) | 9.4 A (approximate) |
Type 1 FPC (without PICs) | 160 W | 3.3 A |
Type 2 FPC (without PICs) | 160 W | 3.3 A |
Type 3 FPC (without PICs) | 160 W | 3.3 A |
Host subsystem (Routing Engine and CB) | 100 W | 2.1 A |
SIB | 38 W | 0.8 A |
AC power supply | 100 W | Not applicable. |
DC power supply | 40 W | 0.8 A |
Cooling system (normal speed) | 140 W | 2.9 A |
Cooling system (full speed) | 200 W | 4.0 A |
PIC—Generalized typical value | 30 W | 0.625 A |
PIC—Generalized maximum value | 52.8 W | 1.1 A |
You can use the information in Table 1 and the M320 Multiservice Edge Router PIC Guide to calculate power consumption for various hardware configurations, input current from a different source voltage, and thermal output, as shown in the following examples for a DC-powered router.
- Example of calculating power consumption for minimum configuration:Base system + 1 FPC + 1 PIC =9.4 A + 3.3 A + 0.625 A = 13.3 A @ –48 VDC = 638 W DC
- Example of calculating power consumption for maximum configuration:Base system + 1 Host subsystem + 2 redundant DC power supplies + 8 FPCs + 32 PICs =9.4 A + 2.1 A + 2(0.8) A + 8(3.3 A) + 32(1.1 A) =9.4 A + 2.1 A + 1.6 A + 26.4 A + 35.2 A = 74.7 A @ –48 VDC =3,586 W DC
- Current requirement adjustment for fans running at full
speed (high temperature environment or cooling component failure):Calculated system current (X) – Cooling (normal) + Cooling (full speed) =X A – 2.9 A + 4.0 A =X A + 1.1 A
- Input current from a DC source other than –48 VDC
(based on maximum configuration; applies to DC power supply only):(–54 VDC input) x (input current X) = (–48 VDC input) x (input current Y)54 x X = 48 x 57.9 AX = 48 x 57.9 A/54 = 51.5 A
- Example of calculating system thermal output for a DC-powered
router:Watts DC/0.293 = BTU/hr3,586/0.293 = 12,239 BTU/hr
- Example of calculating system thermal output for an AC-powered
router:Watts DC/85% AC PEM efficiency/0.293 = BTU/hr3,586/0.85/0.293 = 14,398 BTU/hr
