Liebert 8 Tons Humidifier User Manual


 
Microprocessor Control
36
3.3 Setpoints
Setpoints and system setup parameters are kept in nonvolatile memory. Selecting SETPOINTS from
the Main Menu will display the following selections:
TEMPERATURE SETPOINT
TEMPERATURE SENSITIVITY
HUMIDITY SETPOINT
HUMIDITY SENSITIVITY
HIGH TEMPERATURE ALARM
LOW TEMPERATURE ALARM
HIGH HUMIDITY ALARM
LOW HUMIDITY ALARM
Scroll through this sub-menu by using the UP/DOWN arrow, then press ENTER to select a particu-
lar function. To change a value, press ENTER and use the UP/DOWN arrows. When the value has
been changed, press ENTER to store the value. For example, to change the temperature setpoint
from the main status display:
1. Press MENU key to display main menu.
2. Scroll to “SETPOINTS” using the UP/DOWN arrow key. Press ENTER.
3. Scroll to “TEMP SETPT” using the UP/DOWN arrow key. Press ENTER.
4. Use the UP/DOWN arrow to change the value. Press ENTER.
3.4 Status
The operator can monitor the percentage heating, cooling, dehumidifying, and humidifying status of
the unit by selecting “STATUS” from the main menu.
3.5 Active Alarms
The operator can monitor the alarms status by selecting “ACTIVE ALARMS” which will display a
“Alarm XX of YY” alert and description. If more than one alarm is activated, use the Up/Down arrow
to scroll through the alarms list. (“XX” reference is the number of the alarm shown, and the “YY” ref-
erence is the total number of alarms activated).
3.6 Alarm History
A history of the 10 most recent alarms is kept in non-volatile memory complete with the date and
time of their occurrence. The first alarm in the history is the most recent, and the 10th is the oldest. If
the ALARM HISTORY is full (10 alarms) and a new alarm occurs, the oldest is lost and the newest is
saved in ALARM HISTORY location 1.The rest are moved down the list by 1. ALARM HISTORY on
new units may show the results of factory testing.
Table 10 Default setpoints and allowable ranges
Setpoint Default Range
Temperature Setpoint 72°F 40-90°F (5-32°C)
Temperature Sensitivity 2.0
°F1-9.9°F (0.6-5.6°C)
Humidity Setpoint 50% 20-80% RH
Humidity Sensitivity 5% 1-30% RH
High Temperature Alarm 80
°F
35-95
°F
(2-35
°C)
Low Temperature Alarm 65°F
35-95
°F
(2-35
°C)
High Humidity Alarm 60% 15-85% RH
Low Humidity Alarm 40% 15-85% RH