Manual 2100-670I
Page
32 of 47
Supply Temperature Sensor Failure Alarm
When the sensor reads a value that is outside of the
acceptable -41.0 to 303.0° range, an alarm will be
generated indicating the sensor has failed.
This alarm is fixed and cannot be adjusted.
High Supply Air Temperature Alarm
When the supply air temperature measurement for
the economizer to be enabled is above the outdoor air
temperature setpoint (70°F) for 120 seconds, an alarm
will be generated and the economizer will be disabled
until the cooling call has been removed. This alarm will
automatically reset once the economizer is no longer
disabled.
To change the high supply air temperature alarm:
1. Press MENU key to go to the Main Menu screen.
2. Press UP or DOWN keys and ENTER key to enter
USER password 2000.
3. Press UP or DOWN keys to scroll to
System Config
;
press ENTER key.
4. Press UP or DOWN keys to scroll to
Alarm Setup
(A5)
; press ENTER key.
5. Press ENTER key to scroll to
Hi and Diff
value (see
Figure 52).
6. Press UP or DOWN keys to change the differential
to the desired value.
7. Press ENTER key to save and scroll to the next
parameter.
Low Supply Air Temperature Alarm
When the supply air temperature is below 45°F for
120 seconds, an alarm will be generated and the
economizer will be disabled until the cooling call has
been removed. This alarm will automatically reset when
the economizer is no longer disabled.
To change the low supply air temperature alarm:
1. Press MENU key to go to the Main Menu screen.
2. Press UP or DOWN keys and ENTER key to enter
USER password 2000.
3. Press UP or DOWN keys to scroll to
System Config
;
press ENTER key.
4. Press UP or DOWN keys to scroll to
Alarm Setup
(A5)
; press ENTER key.
5. Press ENTER key to scroll to
Lo and Diff
value (see
Figure 52).
6. Press UP or DOWN keys to change the differential
to the desired value.
7. Press ENTER key to save value and scroll to
Delay
.
8. Press UP or DOWN keys to adjust the delay value.
NOTE:
This delay is also applied to the high supply air
temperature alarm.
9. Press ENTER key to save.
Economizer Operation
The economizer has four types of operation. The
first mode is "None" where the economizer is never
utilized, except for emergency purposes. The second
mode is "Dry Bulb" where the outdoor temperature
is the only consideration for economizer use on a
freecooling call. The third mode is "TempHum" where
the outdoor temperature and humidity are considered
for economizer use on a freecooling call. The fourth
mode is "Enthalpy" where the outdoor temperature,
humidity and calculated dew point are considered for
economizer operation on a freecooling call.
To change the economizer type:
1. Press MENU key to go to the Main Menu screen.
2. Press UP or DOWN keys and ENTER key to enter
USER password 2000.
3. Press UP or DOWN keys to scroll to
System Config
;
press ENTER key.
4. Press UP or DOWN keys to scroll to
Economizer
Setup (A2)
; press ENTER key.
5. Press ENTER key to scroll to
Type
(see Figure 53).
FIGURE 52
Adjusting Supply Air Temperature Differential
FIGURE 53
Economizer Setup
