Liebert 3000 Air Conditioner User Manual


 
Operation with Advanced Microprocessor Controls
13
2.5.4 Change Passwords
The display prompts you to enter a three digit password when making changes. The system includes
two (2) passwords, one for setpoints and one for setup. The system allows the passwords to be changed
by first entering the present password, factory set as “123” for setpoints and “321” for setup. The pass-
word function provides system security, so only personnel authorized to make changes should know
the passwords. If unauthorized changes are being made, the passwords may be compromised and new
ones should be selected. The password function can be disabled by setting DIP switch 8 to OFF.
2.6 Date and Time
The current date and time is available through the display. This feature allows the date and time to
be read or changed and is accessed by selecting “DATE AND TIME” from the Main Menu.
The “DATE AND TIME” is used only by the control for recording the Alarm History.
2.7 Status Display
The Status Display selected from the Main Menu is the same Status Display that is normally on the
screen. While the Main Menu is displayed, you can press the MENU/ESC key to return to the Status
Display.
2.8 Control Circuit Board
The control circuit board is located inside the unit behind the LCD display and control key panel.
Open the front panel for access to the board.
The control board includes an adjustment for LCD display contrast, nonvolatile memory, DIP
switches (which should not require customer changes), control output LEDs and jumpers for board
configuration. The jumpers should be placed as follows:
P5—removed
P12—removed
P19—installed on Pins 1 and 2
P47—installed on Pins 1 and 2
P48—installed on Pins 1 and 2
P50—all jumpers installed for 4-20 mA analog inputs. See 4.5.1 - Connecting the Analog Sen-
sors for other configurations
P51—removed
2.8.1 LCD Display Contrast
The level of contrast due to viewing angle of the LCD display can be adjusted using a small thumb
wheel at the upper left of the control board just under the cable going to the display. The control is
labeled R6.
NOTE
The clock uses the 24 hour system (For example: 17:00 would be 5:00 PM). The date and time
are backed up by battery.
NOTE
The system automatically returns to the Status Display in five minutes if no
control keys are pressed.
NOTE
The LED backlighting on the text (4 x 20) display is always lit.