2-8 CHAPTER 2: INSTALLING THE LINKBUILDER MSH
DUA1800-0AAA04
The Power Supply Unit And Power Inlet Panel
We recommend that you install two units. Further power supply
units are available from your LinkBuilder s upplier: see Appendix E
Ordering Information. See Appendix C for details of configuring
resilient supplies and calculating supply requirements.
One PSU installed into the MSH chassis can provide up to 375W
or 525W of power (maximum- depending on which PSU was
purchased), allowing the use of various types and numbers of
modules.
With two Units installed, each contributes approximately half o f
the power requirement of the chassis. This enables the load to be
shared, increasing the reliability of the PSUs. F ailure of one of the
PSUs would result in the other unit tak ing over the full load,
without any interruption to the operation of the MSH.
To ensure the operation of a resilient power supply in the MSH
chassis, you are advised to follow the instructions in Appendix C
and calculate total power and current consumptions before
installing the modules.
Power is supplied to the chassis via two IE C sockets on the power
inlet panel which is located between the right-hand PSU slot (PSU
2) and the first module slot. The top IEC socket supplies power to
the left-hand PSU (PSU 1), the lower socket suppli es to the
right-hand PSU (PSU 2). The unit does not have an ON/OFF
switch, so it is isolated from power by disconnecting the
appropriate power supply cable. The power inlet panel also
contains two replaceable fuses: see the section entitled Replacing
The Power Supply Fuses.
The MSH PSU features automatic voltage selection according to
the supply that you are using.
A power lead terminated at both ends is suppli ed with the
chassis. Refer to the Safety Information on the previous pages.

Chassis.bk : CHAPTER2 Page 8 Monday, February 10, 1997 1:11 PM