Manual 2100-695C
Page
35 of 56
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 can only be activated during
free cooling and will automatically reset once 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
.
5. Press ENTER key to scroll to
Lo and Diff
value (see
Figure 56).
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 free cooling
call. The third mode is "TempHum" where the outdoor
temperature and humidity are considered for economizer
use on a free cooling call. The fourth mode is "Enthalpy"
where the outdoor temperature, humidity and calculated
dew point are considered for economizer operation on a
free cooling call.
To change the economizer type and setpoints:
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
.
5. Press ENTER key to scroll to
Control Type
(see
Figure 57).
High Supply Air Temperature Alarm
When the supply air temperature is above 80°F for
120 seconds, an alarm will be generated and the
economizer will be disabled until the cooling call has
been removed. This alarm can only be activated during
free cooling and 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
.
5. Press ENTER key to scroll to
Hi and Diff
value (see
Figure 56).
6. Press UP or DOWN keys to change the differential
to the desired value.
7. Press ENTER key to save the value.
6. Press UP or DOWN keys to change the
Type
desired
value to
None
,
Dry Bulb
,
TempHum
or
Enthalpy
.
7. Press ENTER key to save the value and scroll to
the next parameter.
NOTE:
Some of the following parameters may not be
present until the control type that it is used with
is selected.
8. If control type is other than
None
, the cursor
should now be on the
OD Temp Set
parameter.
FIGURE 56
Adjusting Supply Air Temperature Differential
FIGURE 57
Economizer Setup A2
