Cooling System; Power Supplies - Juniper EX8208 Complete Hardware Manual

Complete Hardware Guide for EX8208 Ethernet Switches

Cooling System

Power Supplies

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Documentation
6
The cooling system in an EX8208 switch consists of a hot-removable and hot-insertable
fan tray. The fan tray contains 12 fans. The fan tray installs vertically on the left front of
the chassis and provides side-to-side chassis cooling. See "Cooling System and Airflow
in an EX8208 Switch" on page 54.
Power supplies for the EX8208 switch are fully redundant, load-sharing, and
hot-removable and hot-insertable field-replaceable units (FRUs). Each EX8208 switch
chassis can hold up to six 2000 W AC, six 3000 W AC, or six 2000 W DC power supplies.
The 2000 W AC power supplies support both low-voltage line (100–120 VAC) and
high-voltage line (200–240 VAC) AC power configurations on an EX8208 switch. Each
2000 W AC power supply delivers 2000 W of power at high-voltage line (200–240 VAC)
or 1200 W at low-voltage line (100–120 VAC) to the EX8208 chassis.
Each 3000 W AC power supply delivers 3000 W of power at high-voltage line (200–240
VAC) input to the EX8208 chassis. Low-voltage line input is not supported for the 3000
W AC power supplies on the EX8208 switch.
Each DC power supply delivers 2000 W of power to the chassis when the input voltage
is in the range –40 VDC through –72 VDC.
Only two AC power supplies are required for the base AC configuration and switch
powerup. The redundant AC configuration ships with six AC power supplies to provide
the capacity to power the system using N+1 or N+N power redundancy. See "AC Power
Supply in an EX8200 Switch" on page 41 and "EX8208 Switch Configurations" on page 7.
The redundant DC configuration ships with four DC power supplies. The dual inputs of
the DC supplies provide direct support for N+N power redundancy. The redundant
configuration also provides sufficient capacity for N+1 redundancy in most configurations;
if necessary, up to two additional DC supplies can be added to the system. See "DC Power
Supply in an EX8200 Switch" on page 49 and "EX8208 Switch Configurations" on page 7.
CAUTION: Mixing different types of power supplies in the same chassis is
not supported.
Field-Replaceable Units in an EX8208 Switch on page 25
Connecting and Configuring an EX Series Switch (CLI Procedure) on page 188
Connecting and Configuring an EX Series Switch (J-Web Procedure) on page 190
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