Cisco Systems ASR 903 manual Redundancy, Dying Gasp, Status LEDs, DC Power Specifications

Chapter 1 Cisco ASR 903 Router Overview

Cisco ASR 903 Router Features

•AC Power Specifications, page 1-5

Redundancy

The Cisco ASR 903 Router chassis includes a slot for an optional redundant power supply. The redundant power supply option provides a second, identical power supply to ensure that power to the chassis continues uninterrupted if one power supply fails or input power on one line fails. The Cisco ASR 903 Router supports current sharing between the power supplies.

If you install a redundant power supply on the Cisco ASR 903 Router, we recommend that you connect each power supply to a separate input power source in order to ensure that the router maintains power in the event of a power interruption caused by an electrical failure, a wiring fault, or a tripped circuit breaker.

Dying Gasp

The Cisco ASR 903 Router DC power supply supports the Dying Gasp feature, which allows the router to provide an input power loss notification to the RSP so that the RSP can send appropriate SNMP traps or OAM messages and update log files on the router. With the DC power supply, the router supports a minimum input power loss detection time of 2 milliseconds (DC) and continued operation of at least 6 milliseconds (DC) after the notification.

Note Continued DC power supply operation may vary for voltages other than +24/-48V.

Status LEDs

LEDs are also provided on each power supply to indicate the status of the input power and the health of the power supply. For more information about the LEDs on the Cisco ASR 903 Router, see Chapter 5, “Troubleshooting.”

DC Power Specifications

The Cisco ASR 903 Router uses a +24/-48 Volts Direct Current (VDC) (-19 to -72 VDC supply tolerance) power supply. The power supply provides 550 W output power for system 12 V power. The power supply is field replaceable, hot-swappable, and operates separately from the fan tray.

The power supply uses a three-position terminal block-style connector with labeled connections for ground, -24/48 V, and +24/48 V. The power supply contains a front panel with mounting screws, a handle for insertion and removal, and two status LEDs. No ON/OFF switch is provided.

Table 1-2summarizes the input power specifications for the Cisco ASR 903 Router DC power supply.

		Table 1-2	DC Power Supply Specifications
		Part number		A900-PWR550-D
		Input power specification		+24/-48 VDC
		Input voltage		-48/-60 VDC
		Minimum input voltage		-19.2 VDC
		Maximum input voltage		-72 VDC
	Cisco ASR 903 Router Hardware Installation Guide
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