Dunham-Bush ACXi 165-5SP-LN, Installation, Operation And Maintenance Manual

Page: 32 / 43

4.0 ELECTRICAL
4.4 MICROCOMPUTER
CONTROLLER
This unit is controlled by a microcomputer
control system. The system is composed of four
microcomputer boards, a display board and
analog and digital sensors. The following
sections describe the system and how to operate
it.
The display board has a 20-key keypad and a 2 x
40 LCD display. The keypad and display can be
used to determine the status of the compressor,
and refrigeration system. Various setpoints can
also be displayed and altered.
The status of the machine can also be monitored
by a computer terminal either locally or remotely
by a modem. The terminal must be able to handle
RS232 communications. For more information,
Please contact Dunham-Bush Industries, M & E
Service Department.
4.4.1 TO DISPLAY DATA FROM THE
MENU
1. Press the MENU key.
2. Use the up or down arrow keys to
select the type of information desired.
The main menu items are:
DATE & TIME SET
CONTROL POINTS
ANALOG SENSORS
DIGITAL SENSORS
SETPOINTS A & B
ALARMS
AUTHORIZATION
3. Press the ENTER key.
4. Use the up or down arrow keys to
select the desired data. For control
points, additional data such as
compressor operating hours and
number of starts can be viewed with
the right and left arrow keys.
NOTE:
When displaying analog
sensors, the PAGE MODE key can be
pressed to display two new analog
inputs after each arrow key is pressed.
Press PAGE MODE again to return to
displaying one new analog input.
4.4.2 TO RESET ALL CONTROL
POINTS TO COMPUTER
CONTROL
1. Press the RESET key. The display will
show RESET ALL CPs to COM
MODE? N Y
2. Press the right arrow key to select Y.
3. Press the ENTER key. The reset will
not be accepted if a lockout control
point is active. Resolve the problem
and reset again.
4.4.3 TO DISPLAY ALARMS
1. Press the MENU key.
2. Use the up or down arrow to select
ALARMS.
3. Press ENTER.
4. The day, time, and alarm code is
displayed. Alarm 1 is the most recent
alarm.
5. Press the down arrow to view previous
alarms.
6. Determine identity of alarm from
alarm codes on computer instruction
label.
4.4.4 TO BECOME AUTHORIZED
1. Select AUTHORIZATION on the
main menu. Press ENTER.
2. If the current status shown is VIEW,
press the authorization code (64) on
the number keys.
3. Press ENTER. the current status will
change to PROG (program) if
accepted.
4.4.5 TO ALTER SETPOINT DATA
1. You must be authorized and in the
PROG mode. See section 4.4.4.
2. Select SETPOINTS A & B on the
main menu. Press ENTER.
3. Use the up or down arrow keys to
select the setpoint to be changed. Press
ENTER. A cursor will flash over the
setpoint A value.
- 32 -