1-8
Table 1-4
Description of PEMs
PEM
Description
Max number of
supported PSUs
LSTM2PEMC6
(PEM-C20)
Applied to 110 V or 220 V single-phase three-wire AC
power supply system
Each PEM provides six standalone C20 (16A) sockets
numbered in two rows, 1, 3 and 5 on the top and 2, 4 and
6 on the bottom, from left to right.
6 (each
C20 socket for one
PSU)
Fan Tray
Both the S12508 and the S12518 have two fan trays (one on top of the other) to provide the following
functions:
z
Load balancing and 1 + 1 redundancy for effective heat dissipation and single-point failure
prevention.
z
Status monitoring: Fan rotation speed monitoring, fault alarms, and so on.
z
Automatic speed adjustment: Supports to adjust the fan rotation speed automatically according to
the operation situation of the device. The speed of each fan group (four fan groups, each having
three fans) is controlled to reduce noises and energy consumption effectively.
z
Information indication: Two indicators on the front panel of a fan tray provide the fan tray operating
information.
A fan tray consists of 12 fan units measuring 120 × 120 × 38 mm (4.72 × 4.72 ×1.50 in.) and one fan
monitoring board. Fans receive DC power from the backplane. Fan trays are hot-swappable.
z
The power of an S12508 fan tray ranges from 25W to 130 W.
z
The power of an S12518 fan tray ranges from 120W to 650 W.
The S12508 and S12518 use different fan trays and do not support the intermixing of different fan trays.
The appearance and indicators of the S12518 fan tray are similar to those of the S12508. The following
uses the S12508 fan tray as an example.
Figure 1-7
S12508 fan tray
