Qfx10000 Grounding Cable And Lug Specifications; Table 55: Total Power Available - Juniper QFX10008 Hardware Manual

QFX10008 Switch Hardware Guide

QFX10000 Grounding Cable and Lug Specifications

128
CAUTION: Using the calculated minimum power configuration does not
prevent the system from raising a power alarm. To ensure you do not log
power alarms, you must configure your switch for N+1 power supplies.
To calculate the number of power supplies required for your minimum switch
configuration:
Determine the power available from the power supplies. AC power supplies are 2700 W
1.
and DC power supplies are 2500 W
for installed power supplies.
NOTE: DC systems are only supported in the redundant configuration.

Table 55: Total Power Available

Number of Power Supplies
3
4
5
6–(for redundancy only)
Determine the total power required for your configuration with line cards installed.
2.
The total power available to the chassis is calculated by dividing the wattage needed
by the power rating, then rounding up.
In the previous examples, we calculated that a QFX10008 AC system would require
9385 W with five QFX10000-36Q and three QFX10000-30C line cards. In this example,
we calculate the total power available for this configuration:
= (9385 W) / (2700 W)
= 3.47
Round up the result to 4 AC power supplies, which is the minimum number without
a redundant power supply (RPS). Add one more power supply for a N+1 redundancy.
In this example, a total of five power supplies are needed.
For installations that require a separate grounding conductor to the chassis, the switch
must be adequately grounded before power is connected to ensure proper operation
and to meet safety and electromagnetic interference (EMI) requirements. To ground a
Table 55 on page 128 shows the power available
AC
8100 W
10800 W
13500 W
—
Copyright © 2019, Juniper Networks, Inc.
DC
12500 W
—