Figure 55 Economizer Setup - Dry Bulb Control; Figure 56 Economizer Setup - Temphum Control; Figure 57 Economizer Setup - Enthalpy Control - Bard MEGA-TEC W180B Service Instructions Manual

11. The cursor should now be on Delay parameter.
12. Press UP or DOWN keys to change the parameter
to the desired value.
13. Press ENTER key to save the value and move to
the next parameter.
14. The cursor is now on the Min Position parameter.
15. Press UP or DOWN keys to change the parameter
to the desired value (see Economizer Operation −
Minimum Position on page 36 for more information).
16. Press ENTER key to save the value.
17. Press the DOWN key to navigate to the Economizer
Setup A3 screen.
NOTE: The Economizer Setup A3 screen will not display
if economizer mode is set to None. Also, the
contents of the screen will change depending
on which type is chosen: Dry Bulb (Figure 55),
TempHum (Figure 56) or Enthalpy (Figure 57).
The following menu shows the Enthalpy content
which also contains parameters that would
be shown on Dry Bulb (temperature only) and
TempHum (temperature and humidity only).
18. Press ENTER key to scroll to OA Temp Set (on
Drybulb Control and Temp/Hum Control A3
screens, this parameter will be titled Outdoor Set).
19. Press UP or DOWN keys to change the temperature
setpoint to desired value.
20. Press ENTER key to save the value and scroll to
Off Diff.
21. Press UP or DOWN keys to adjust the outdoor
temperature differential for which the economizer
is re-enabled.
22. Press ENTER key to save the value and scroll to OA
Hum Set.
23. Press UP or DOWN keys to adjust the humidity
setpoint to desired value.
24. Press ENTER key to save the value and scroll to On
Diff.
25. Press UP or DOWN keys to adjust the outdoor
humidity differential for which the economizer is
re-enabled.
26. Press ENTER key to save the value and scroll to
Dew Pt. Set.
27. Press UP or DOWN keys to adjust the outdoor dew
point setpoint for economizer operation to the
desired value.
28. Press ENTER key to save the value and scroll to On
Diff.
29. Press UP or DOWN keys to adjust the dew point
differential for which the economizer is re-enabled.
30. Press ENTER key to save the value.
FIGURE 55
Economizer Setup – Dry Bulb Control
FIGURE 56
Economizer Setup – Temp/Hum Control
FIGURE 57
Economizer Setup – Enthalpy Control
31. Press ESCAPE key several times to return to Main
Menu screen.
See Table 11 on page 36 for default settings for
economizer operation.
When the economizer is activated during a free cooling
call only, using any of the previously mentioned modes,
a 0-10V analog signal will be sent to the economizer
actuator. The actuator will then open and close the
damper blades to maintain a mixed air temperature of
55°F. When the mixed air temperature increases, the
damper will open and when the mixed air temperature
decreases, the damper will close.
The economizer may be disabled by the LC if the
system determines it needs to enter dehumidification
mode. More information about the dehumidification
Manual 2100-749
Page 35 of 68