Allied Telesis SwitchBlade 4000 Series Switch Hardware Reference - Manual (Page 8)

8 SwitchBlade 4000 Series Switch
C613-03060-00 REV H
The four slot chassis (AT-SB4104) provides space for the following units:
• two switch controller cards (or one switch controller and one
bandwidth expander)
• four line cards
• two PSUs
• one AT-SB4151 fan tray
Both chassis types are available in either AC or DC power supply.
The eight slot AC chassis models can be supplied with either dual or triple
power feeds. These models are listed below:
• AT-SB108-00 triple AC feed
• AT-SB108-60 dual AC feed
All the four slot and DC chassis models are supplied with dual power feeds.
All SwitchBlade controller cards and line cards are compatible with both the
four and eight slot chassis types. For example, an AT-SB4211 switch controller
can be used in both the eight slot chassis and the four slot chassis.
The bandwidth expander (AT-SB4215) can be used only in switch controller
bay B of the four slot chassis.
Fan trays can be used only in their own particular chassis type. The AT-SB4151
fan tray can only be used in the four slot chassis, while the AT-SB4152 fan tray
can only be used in the eight slot chassis.
Power Feed Options
The eight slot AC chassis is available with either triple AC power feeds or dual
AC power feeds. The eight slot DC chassis is only available with dual DC
power feeds.
Eight Slot Triple Feed
Models
In these models each power feed connects only to its own associated power
supply. Therefore, if power to a particular feed is lost, then the PSU associated
with that feed will cease to operate. If the chassis contains three PSUs then
power will continue be drawn from the remaining two PSUs. However, with
only two PSUs installed, a disconnected power feed will result in power only
being supplied from the single remaining PSU, which, depending on
configuration, may - or may not - be sufficient to meet the chassis’ full power
requirements.
Eight Slot Dual Feed
Models
In these models, two feeds supply power to the chassis, which can contain up
to three PSUs. To provide power feed redundancy, a relay is used to enable
each of the two feeds to supply power to both its own PSU, plus the PSU
located in the centre bay, as shown.