Lennox PRODIGY M2 User Manual

9. Supply Air Delivery
Page 41
PRODIGYT M2 UNIT CONTROLLER
B Start system. Analog output value will be at the ManRS value (%).
C Monitor system. System should be stable. If system is not stable at this point check for other problems. Adjusting the PID
parameters will not solve this problem.
D If system is stable, gradually increase the P" parameter until system starts oscillating (moving above and below
setpoint, continuously).
E Reduce the P" parameter to 40−70% of the value set in step 6.
F Gradually start adding some I" by setting the I" ECTO parameter to 127 and reduce setting until the steady state
error (offset) is reduced to an acceptable level.
G If necessary, increase the D" parameter to reduce overshoot. Use of D" can increase settling time and/or lead to
instability.
H NOTE − In most cases, it’s best to not use any D" parameter.
Table 30. Summary of PID Constants ECTO Parameters
Variable Air Delivery PID Constants
No. Name Min Default Max
Units Description
0.09 VAV_PID_ManRS
0
0
60
60
100
100
Counts
P:%
VAV supply PID manual reset value. If minimum output, ECTO 0.06 or
0.07 is greater, a computed ManRS value is used. See ECTO 0.06 and
0.07.
0.10 PID_P_Constant 0 17 127 Counts VAV or CAVB supply PID Proportional constant.
0.11 PID_I_Constant 0 12 127 Counts VAV or CAVB supply PID Integral constant.
0.12 PID_D_Constant 0 0 127 Counts VAV or CAVB supply PID derivative constant.
VAV Exhaust Fan PID Control Constants
8.22 Exh_Fan_ManRS
0
0
50
50
100
100
Counts
P: %
Exhaust fan PID loop manual reset value.
Stg_1_Off_Delay 0 100 200 A:Sec. Stage 1 off−delay. (Only used for 2 stage operation)
8.23
Exh_Fan_PID_P_
Constant
0 20 255 Counts
Exhaust fan PID loop proportional constant. The P constant must be
limited to 127. Recommended setting = 17.
Stg_2_SP
0
0
−0.5
.78
20
−.42
10.0
100
0.5
R:Volts
P:%
M:"w.c.
Staged 2 setpoint.
8.24
Exh_Fan_PID_I_
Constant
0 64 255 Counts
Exhaust fan PID loop integral constant. The I constant must be limited
to 127. Recommended setting = 12.
Stg_2_DB
0
0
64
0.25
100
1.0
P:%
L:"w.c.
Staged 2 deadband.
8.25
Exh_Fan_PID_D_
Constant
0 0 127 Counts Exhaust fan PID loop derivative constant.
Stg_2_On_Delay 0 0 254 A: Sec. Staged 2 on−delay.
9.08 AO1_PID_ManRS
0
0
50
50
100
100
Counts
P:%
Analog output channel 1 PID loop manual reset value.
9.09 AO1_PID_P_Constant 0 0 127 Counts Analog output channel 1 PID loop proportional constant.
9.10 AO1_PID_I_Constant 0 0 127 Counts Analog output channel 1 PID loop integral constant.
9.11 AO1_PID_D_Constant 0 0 127 Counts Analog output channel 1 PID loop derivative constant.
General Purpose PID Control Constants for GP Analog Output 2 (TB22−12)
9.19 AO2_PID_ ManRS
0
0
50
50
100
100
Counts
P:%
Analog output channel 2 PID loop manual reset value.
9.20 AO2_PID_P_Constant 0 0 127 Counts Analog output channel 2 PID loop proportional constant.
9.21 AO2_PID_I_Constant 0 0 127 Counts Analog output channel 2 PID loop integral constant.
9.22 AO2_PID_D_Constant 0 0 127 Counts Analog output channel 2 PID loop derivative constant.

Lennox PRODIGY M2 Specifications

General

Brand	Lennox
Model	PRODIGY M2
Category	Controller
Language	English