Technical Documentation

M320 DC Power Electrical Specifications

Table 1 lists the DC power supply and power system electrical specifications.

Table 1: DC Power Supply Electrical Specifications

Item

Specification

Maximum output power

2000 W

DC input voltage

Nominal: –48 VDC, –60 VDC

Operating range: –40.5 to –72 VDC

Note: If the input voltage from the DC power source drops below –40.5 VDC, the routing platform automatically shuts down. During automatic shutdown, the circuit remains active. When the input voltage returns to –42.75 VDC, the router automatically starts up again and the system returns to normal operation within 30 minutes. No operator intervention is required.

DC input current rating

42 A @ –48 VDC

Internal Supplementary Protector

50 A

Table 2: DC Power System Electrical Specifications

Item

Specification

DC input voltage

Operating range: –40.5 to –72 VDC

Note: If the input voltage from the DC power source drops below –40.5 VDC, the routing platform automatically shuts down. During automatic shutdown, the circuit remains active. When the input voltage returns to –42.75 VDC, the router automatically starts up again and the system returns to normal operation within 30 minutes. No operator intervention is required.

DC system current rating

65 A @ –48 VDC (nominal)

Each DC power supply has a single DC input (–48 VDC and return) that requires a dedicated 60 A (–48 VDC) circuit breaker. The DC power supplies in slots PEM0 and PEM1 must be powered by dedicated power feeds derived from feed A, and the DC power supplies in slots PEM2 and PEM3 must be powered by dedicated power feeds derived from feed B. This configuration provides the commonly deployed A/B feed redundancy for the system.

Note: If you plan to operate a maximally configured DC-powered router, we recommend that you provision at least 65 A @ –48 VDC for the system, or at least 48 A @ –48 VDC for each power supply. Use a facility circuit breaker rated for 60 A (–48 VDC) minimum for each DC power supply. Doing so enables you to operate the router in any configuration without upgrading the power infrastructure.

If you plan to operate a DC-powered router at less than the maximum configuration and do not provision a 60 A (–48 VDC) circuit breaker, we recommend that you provision a circuit breaker for each DC power supply rated for at least 125% of the continuous current that the system draws at –48 VDC.

Published: 2009-09-26