Installation
ACC-SVN155D-EN
11
Minimum Position Setting
To adjust the minimum position setting and check out the
economizer, the power must be connected.
Close the unit disconnect and place the zone sensor fan
selector in the fan "ON" position and the heat/cool selector
in the "OFF" position. This will place the damper in the
minimum ventilation position.
To adjust the minimum position setting for the required
ventilation air, turn the potentiometer (on the ECA)
clockwise to "open" (to increase the amount of ventilation)
or counterclockwise to "close" (to decrease the amount of
ventilation). The damper will open to this setting each time
the blower circuit is energized.
When adjusting minimum position, the damper may move
to the new setting in several small steps. Once the damper
has remained in position for 10 - 15 seconds without
movement, it can be assumed it is at the new position.
Replace the filter access panel.
The damper will close when the blower circuit is de-
energized.
Dry Bulb Settings
Standard economizer dry bulb changeover is field
selectable to 5 outdoor temperatures. See
Table 1
for
potentiometer settings.The selection is made on the ECA.
Reference Enthalpy Settings
Economizer enthalpy changeover is field selectable to 5
points. See
Table 1
for potentiometer settings. The
selection is made on the ECA.
Table 1.
Potentiometer settings
Potentiometer
Setting
Dry Bulb
Enthalpy
A
73ºF (22.8ºC)
27 Btu/lb (63 kJ/kg)
B
70ºF (21.1ºC)
25 Btu/lb (58 kJ/kg)
C
(a)
(a) Factory Setting
67ºF (19.4ºC)
23 Btu/lb (53 kJ/kg)
D
63ºF (17.2ºC)
22 Btu/lb (51 kJ/kg)
E
55ºF (12.8ºC)
19 Btu/lb (44 KJ/Kg)
Table 2.
Economizer control options
Control Option
Enable
Conditions
(a)
(a) Economizing is enabled when these conditions are met.
Dry Bulb (standard)
See
Table 1
Outdoor Air Temp
(OAT)
Reference Enthalpy
(ReliaTel Only)
See
Table 1
Outdoor Humidity
(BAYENTH300*)
Comparative Enthalpy
(ReliaTel Only)
Outdoor Air Enthalpy
3.0 BTU/lb. less than
Return Air Enthalpy
Outdoor Humidity
Return Humidity
Return Temperature
(BAYENTH301*)
Wiring Connections
Locate unit wiring harness plug PPM2A. The plug is
located in the upper left section of the return air section.
Remove the cap covering the plug, and connect to the
economizer wiring harness.
Figure 24.
Electromechanical wiring
Optional Sensors
Required
(b)
(b) Conditions level will be self configured when optional sensors are con-
nected.
