Lennox PRODIGY M2 User Manual

7. Economizer
Page 27
PRODIGYT M2 UNIT CONTROLLER
7.8. Damper Minimum Position Potentiometer
Set economizer DIP switch to DSET" position as shown in figure 10. DSET is a manual mode that locks the economizer into
minimum position. Rotate MIN POS SET potentiometer to the approximate desired damper position.
DSET (Damper Set)
0
100
OPEN
MIN POS SET
Figure 10. Manual Damper Set DIP Switch
Check indicator on damper motor to determine actual damper position. Adjust potentiometer until damper motor reads de-
sired position. See figure 11. Damper minimum position can also be set using ECTO 5.24. This will disable the potentiome-
ter.
Set potentiometer to approximate damper minimum posi-
tion; check actual position on economizer damper motor.
(NOTE: MOTOR ROTATES SLOWLY)
Figure 11. Economizer Damper Min. Position
7.9. Damper Maximum Position
Economizer dampers open to 100% at the default setting. Adjust ECTO parameter 5.23 to reduce the maximum damper
opening for free cooling.
7.10. Motorized Outdoor Air Damper
Set damper position according to Damper Minimum Position Potentiometer" section. For normal operation, make sure the
economizer DIP switch is set to GLO" position as shown in figure 9. The damper will open to the specified position during the
occupied time period and close during the unoccupied time period.
7.11. Economizer Checkout
The following checkout procedures are completed with unit energized. Confirm proper operation of the heartbeat LED.
Step 1 will determine whether the economizer is allowing full damper travel. Use step 2 when the damper does not respond
to step 1.
Steps 3, 4, 5, and 6 checkout the operating modes; checkout only the mode that applies to the unit being worked on. Use
DSET" Operation checkout only when step 1 refers to it.
CAUTION − Power exhaust fans will be functional. To prevent operation of gravity exhaust fans, disconnect power to unit
and then PED jack/plug P/J18.
Step 1. Economizer Output Voltage
A Set the DIP switch to DSET.
B Adjust the MIN POS SET potentiometer to the 0% position (fully counterclockwise). The motor will slowly modulate
to the closed position.
C Adjust the MIN POS SET potentiometer to the 100% position (fully clockwise). The motor will slowly modulate to the
fully opened position.
D If the motor does not respond, go to step 2. If the motor does respond properly, go to the appropriate mode of opera-
tion checkout.
Step 2. DSET" OPERATION
A Set the DIP switch to the DSET" position.
B Adjust the MIN POS SET potentiometer to the 0% position (fully counterclockwise).
C Measure the voltage on P262 between pin 3 (VOT damper control) and pin 2 (GND) using pin 1 as common.
Voltage should read approximately 2 VDC.
D Adjust the MIN POS SET potentiometer to the 100% position (fully clockwise).
NOTE − Allow approximately 30 seconds for voltage to react.

Lennox PRODIGY M2 Specifications

General

Brand	Lennox
Model	PRODIGY M2
Category	Controller
Language	English