Juniper BT8A78CH1, Hardware Overview And Installation Manual

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Each DC PEM features two dual-stud return terminals and two dual-stud feed terminals.
Typically, only one dual-stud terminal is used. The extra dual-stud terminals can be used
for particular applications, such as laboratory applications.
Figure 8: BTI7814 14-Slot Chassis DC Power Entry Module
The DC PEMs are located on the rear of the chassis. The slots are numbered
PEM 1
through
PEM 4
(from right to left).
PEM 1
and
PEM 2
power one set of six channels, and
PEM 3
and
PEM 4
power the other set of six channels. For details on the power distribution plan, see
“BTI7814 Power Distribution Plan” on page 40 .
There is a direct correlation between the DC PEM slots and the internal shelf input
terminals.
The external A feed pair consists of two individual feeds, A1 and A2 , which connect to
the external input terminals of PEM 1 and PEM 3 . The DC outputs of PEM 1 and PEM 3
supply power to the A1 and A2 internal shelf input terminals respectively.
Similarly, the external
B
feed pair consists of two individual feeds,
B1
and
B2
, which
connect to the external input terminals of
PEM 2
and
PEM 4
. The DC outputs of
PEM 2
and
PEM 4
supply power to the
B1
and
B2
internal shelf input terminals respectively.
This is shown in the following table along with the external breaker requirements for each
individual feed:
External Breaker
Requirements Internal Shelf Input
Terminals
DC PEM Slots External Feeds
125A A1 PEM 1 A1
125A B1 PEM 2 B1
125A A2 PEM 3 A2
125A B2 PEM 4 B2
Copyright © 2019, Juniper Networks, Inc. 42
BTI7800 Series Hardware Overview and Installation Guide