Juniper Networks M160 manual Power System, Alarm Relay Contacts and Bits Input Ports

Hardware Component Overview

YELLOW ALARM (see Figure 16). A system condition that causes the red or yellow alarm LED to light on the craft interface also activates the corresponding alarm relay contact. For instructions for attaching a device to the alarm relay contacts, see “Connecting to an External Alarm-Reporting Device” on page 115.

Figure 16: Alarm Relay Contacts and BITS Input Ports

BITS A

LINK

BITS B

LINK

RED ALARM

NC

C

NO

NC

C

NO

YELLOW

ALARM

BITS input ports

Alarm relay contacts

1173

Power System

The router uses DC power. There are two load-sharing, pass-through power supplies located at the bottom rear of the chassis, as shown in Figure 2. The power supplies connect to the midplane, which distributes power to router components according to their individual voltage requirements. When the power supplies are installed and operational, they automatically share the electrical load. If a power supply stops functioning for any reason, the remaining power supplies instantly begin providing all the power the router needs for normal functioning and can provide full power indefinitely.

Power supplies are hot-removable and hot-insertable, as described in Field-Replaceable Units (FRUs) on page 4. To avoid electrical injury, carefully follow the instructions in “Replacing a Power Supply” on page 197.

NOTE: After powering off a power supply, wait at least 60 seconds before turning it back on. After powering on a power supply, wait at least 60 seconds before turning it off.

If the router is completely powered down when you power on the power supply, the Routing Engine boots as the power supply completes its startup sequence. If

Power System 35