Maintaining the EX9253 Power System
Powering Off an EX9253 Switch
Before you begin to power off the switch:
Ensure that you have taken the necessary precautions to prevent electrostatic discharge (ESD) damage (See Prevention of Electrostatic Discharge Damage).
Ensure that you have the following parts and tools available to power off an EX9253 switch:
An ESD wrist strap
An external management device such as a PC
The appropriate cable to connect the external management device to the console port labeled CON on the switch
After powering off a power supply, wait at least five seconds before turning it back on.
To power off the switch:
To power on the switch again, press the button labeled OFFLINE on the primary Routing Engine of the switch for one second or remove the RE and install it.
You can take the switch offline by pressing the button labeled OFFLINE on the primary Routing Engine of the switch for three seconds.
Removing an AC Power Supply from an EX9253 Switch
Before you begin to remove an AC power supply:
Ensure you understand how to prevent electrostatic discharge (ESD) damage (see Prevention of Electrostatic Discharge Damage).
Ensure that you have the following parts and tools available:
An ESD wrist strap
A replacement power supply or a cover panel for the power supply slot
The AC power supply in an EX9253 switch is a hot-removable and hot-insertable field-replaceable unit (FRU). You can remove and replace it while the switch is running without turning off power to the switch or disrupting switching functions. A minimum of two high line power supplies or three low line must be installed in the switch for non-redundant operation. To ensure proper operation of the switch, you must install a replacement power supply shortly after removing a power supply from the chassis. The power supplies are installed in the slots labeled PSM0 through PSM5 on the rear of the chassis.
Before you remove a power supply, ensure that you have power supplies sufficient to power the switch that remains in the chassis (see EX9253 Power System).
Do not leave the power supply slot empty for a long time while the switch is operational. Either replace the power supply unit promptly or install a cover panel over the empty slot.
After powering off a power supply, wait for at least 60 seconds before turning it back on.
To remove an AC power supply from an EX9253 switch (see Figure 1):
See Also
Installing an AC Power Supply in an EX9253 Switch
Before you begin to install an AC power supply:
Ensure you understand how to prevent electrostatic discharge (ESD) damage (see Prevention of Electrostatic Discharge Damage).
Ensure that you have the following parts and tools available:
An ESD wrist strap
A Phillips (+) screwdriver, number 2 (not provided)
The AC power supply in an EX9253 switch is a hot-insertable and hot-removable field-replaceable unit (FRU). You can remove and replace it while the switch is running without turning off power to the switch or disrupting switching functions. You can install up to six power supplies in an EX9253 switch. A minimum of two high line power supplies or three low line must be installed in the switch for non-redundant operation. The power supplies are installed in the slots labeled PSM0 through PSM5 on the rear of the chassis.
EX9253 switches use either AC or DC power supplies. Do not mix AC and DC power supplies in a switch.
Each AC power supply must be connected to a dedicated AC power source outlet.
To install an AC power supply in an EX9253 switch (see Figure 2):
If you have a Juniper J-Care service contract, register any addition, change, or upgrade of hardware components at https://www.juniper.net/customers/support/tools/updateinstallbase/ . Failure to do so can result in significant delays if you need replacement parts. This note does not apply if you replace existing components with the same type of component.
To connect power to an AC power supply, see Connecting AC Power to an EX9253 Switch and Powering on the Switch.
Removing a DC Power Supply in an EX9253 Switch
Before you begin to remove a DC power supply:
Ensure that you understand how to prevent electrostatic discharge (ESD) damage (see Prevention of Electrostatic Discharge Damage).
Ensure that you have the following parts and tools available:
An ESD wrist strap
A socket screwdriver
A replacement power supply or cover panel for the power supply slot
The DC power supply in an EX9253 switch is a hot-removable and hot-insertable field-replaceable unit (FRU). You can remove and replace it while the switch is running without turning off power to the switch or disrupting switching functions. To ensure proper operation of the switch, you must install a replacement power supply shortly after removing a power supply from the chassis. The power supplies are installed in the slots labeled PSM0 through PSM5 on the rear of the chassis.
Before you remove a power supply, ensure that you have power supplies sufficient to power the switch that remains in the chassis (see EX9253 Power System).
Do not leave the power supply slot empty for a long time while the switch is operational. Either replace the power supply unit promptly or install a cover panel over the empty slot.
Before performing DC power procedures, ensure that power is removed from the DC circuit. To ensure that all power is off, locate the circuit breaker on the panel board that services the DC circuit, switch the circuit breaker to the off position, and tape the switch handle of the circuit breaker in the off position.
After powering off a power supply, wait for at least 60 seconds before turning it back on.
To remove a DC power supply from an EX9253 switch:
Installing a DC Power Supply in an EX9253 Switch
Before you begin to install a DC power supply:
Ensure you understand how to prevent electrostatic discharge (ESD) damage (see Prevention of Electrostatic Discharge Damage).
Ensure that the voltage across the DC power source cable leads is 0 V and that there is no chance that the cable leads might become active during installation.
Ensure that you have the following parts and tools available:
An ESD wrist strap
A Phillips (+) screwdriver, number 2 (not provided)
The DC power supply in an EX9253 switch is a hot-removable and hot-insertable field-replaceable unit (FRU). You can remove and replace it while the switch is running without turning off power to the switch or disrupting switching functions. You can install up to six DC power supplies in an EX9253 switch. The power supplies are installed in the slots labeled PSM0 through PSM5 on the rear of the chassis.
EX9253 switches use either AC or DC power supplies. Do not mix AC and DC power supplies in a switch.
Before performing DC power procedures, ensure that power is removed from the DC circuit. To ensure that all power is off, locate the circuit breaker on the panel board that services the DC circuit, switch the circuit breaker to the off position, and tape the switch handle of the circuit breaker in the off position.
To install a DC power supply in an EX9253 switch (see Figure 5):
If you have a Juniper J-Care service contract, register any addition, change, or upgrade of hardware components at https://www.juniper.net/customers/support/tools/updateinstallbase/ . Failure to do so can result in significant delays if you need replacement parts. This note does not apply if you replace existing components with the same type of component.
To connect power to a DC power supply, see Connecting DC Power to an EX9253 Switch and Powering on the Switch.
Maintaining Power Supplies in EX9253 Switches
Purpose
For optimum switch performance, verify the condition of the power supplies installed in the chassis.
Action
On a regular basis:
Check the status of the power supplies by issuing the
show chassis environment pem
command. The output for EX9253 switches is similar to the following:user@switch> show chassis environment pem
Make sure that the power and grounding cables are arranged so that they do not obstruct access to other switch components.
Routinely check the status LEDs on the power supply faceplate to determine whether the power supplies are functioning normally.
Check the alarm LED on the front panel. Power supply failure or removal triggers an alarm that causes the LED to light. You can display the associated error messages by issuing the following command:
user@switch> show chassis alarms
Periodically inspect the site to ensure that the grounding and power cables connected to the switch are securely in place and that there is no moisture accumulating near the switch.