Liebert Autochangeover Controllers AC4 - Manual (Page 2)

2
Hardware and Components
The AC4 comes standard with an enclosure, a controller board and a liquid crystal display (LCD).
Enclosure
The AC4 enclosure features a key lock for added
security. The enclosure is made of metal to
accommodate secure conduit fittings and
protect components against environmental
debris.
• The enclosure is designed for easy wire
routing and terminations. Access slots for
communication cables and network wires are
located on both the top and bottom of the
enclosure.
• The enclosure is 2-3/4" deep, allowing for
recess mounting in a wall. The enclosure may
also be flush-mounted.
• The enclosure houses the LCD and the
controller board.
Controller Board
The controller board supports a total of 10
points (four digital inputs, four digital outputs
and two Common Alarm outputs).
The digital inputs are dry contacts. The digital
outputs and Common Alarm outputs are
Form C contact relays. The Common Alarm
output is one output with two sets of contacts.
The point terminations are made using remov-
able terminal blocks. This allows for easier
access to the terminators, streamlining the pro-
cess of connecting external devices to the AC4.
The controller board is a microprocessor-based
platform for program execution.
The firmware, including the operating system
and user-defined data, is stored in nonvolatile
flash read-only memory. Flash ROM may be
easily upgraded at the job site, simplifying the
process of installing new firmware as it
becomes available.
An RS232 operator terminal port is included
with each controller board for operator devices
such as a simple CRT terminal or laptop PC.
Keypad Display
The keypad display is a user interface mounted on the enclosure door of the AC4.
The display provides for complete monitoring
and configuration of the panel and is
password-protected.
The keypad display provides the ability for the
AC4 to operate as a complete standalone
panel.
Back of LCD
Controller Board
Ground wire for LCD
Knockouts and access slots
(top and bottom)
AC4 enclosure - Internal features
LCD for
configuration
and operation
Key
lock
Knockouts and
access slots
on top and
bottom
AC4 enclosure - External features
Point Type Point Count
Digital input 4
Digital output 4
Common Alarm output 2
Keypad
display