Power Supply; Fan Modules; Front Console - Data General NOVA 4/S Manual

Data General Corporation (DGC) has prepared this manual for use by DGC personnel and customers as a guide to the proper installation, operation, and
maintenance of DGC equipment and software. The drawings and specifications contained herein are the property of DGC and shall neither be reproduced in whole or
in part without DGC's prior 'vritten approval nor be implied to grant any license to make, use, or sell equipment manufactured in accordance herewith.
POWER SUPPLY
Each chassis has its own power supply, which is
available with or without battery backup.
16-Slot Power Supply
The 16-slot power supply and distribution system
consists of a VNR (voltage non-regulated) unit that is
vertically mounted to the rear of the chassis and a
slide-in power supply printed circuit board which plugs
into the chassis' backpanel.
The VNR unit converts power from the ac supply line
to non-regulated dc power, which it supplies to the
power supply board via an internal cable. The internal
cable also:
e Carries ac power from the VNR unit to the fan
e Connects the front console switches and indicators
to the backpanel
When the battery backup option is present, the VNR
unit contains a battery that supplies power to the
battery backup circuits in the power supply board.
The power supply board regulates the de voltages from
the VNR unit and supplies the required voltages to the
remainder of the system via the etch on the backpanel.
It also generates the system clocks and supplies them to
the system printed circuit boards via the backpanel.
As an added feature, the 16-slot power supply has a
diagnostic test plug (located on the backpanel) that
allows voltage margining under diagnostic program
control. Use of this plug is described in Chapter 7. In
normal operation, the diagnostic test plug must be
inserted in the Run position.
CAUTION The diagnostic test plug should be
used only by authorized Data General field service
representatives. Other use of this test plug may
significantly degrade the system.
5-Slot Power Supply
The 5-slot distribution system and power supply resides
on a single slide-in power supply printed circuit board.
It converts power from the ac supply line to regulated
de voltages. When the battery backup option is present,
the battery also resides on the power supply board.
The 5-slot power supply supplies the required dc
voltages to the system printed circuit boards via the
etch on the backpanel while it supplies ac power to the
fan modules via the internal cable. The internal cable
also:
« Connects the front console switches and indicators
to the backpanel
e Connects the power switch to the power supply.
The 5-slot power supply also generates the system
clocks and supplies them to the system printed circuit
boards via the backpanel.
For more information about the operation of the 5-slot
power supply, refer to Part II, Chapters 6 and 10.
FAN MODULES
Both the 16 and 5-slot fan modules reside on the left
side of their respective chassis. They draw air from
outside the cabinet and force it through the chassis. On
the 16-slot chassis, the fan module, containing four fans,
slides into the chassis from the front of the unit. On the
D-slot chassis, two fans mount on the inside of the
chassis cover.
FRONT CONSOLE
The front console assembly mounts on the fan module
in the 16-slot chassis and on the cover in the 5-slot
chassis. It consists of three switches and three indicator
lights. The switches allow the user to control basic
functions such as power up/down, program load and
reset while the indicator lights provide information
concerning power status and the CPU's operating mode.
The remaining operator control functions are
implemented by a virtual console which is described
under the "CPU Board" below. Operator information
for both consoles appears in Part I, Chapter 2.