Lennox Prodigy M2 Application Manual page 60

15. Service Relay
15.1. Service Relay Operation
The M2 Service Relay output (A55_P298−8) default operation indicates that service is required. Table 40 indicates these
critical alarms with an asterisk.
If the default operation is not required, the Service Relay output may be used as a control output. Use ECTO 7.22 to choose
the input which will trigger the Service Relay output. The formula X + (32
39.
If ECTO 7.22 input sources 7−9 are used, the setpoint and deadband must be set with ECTO 7.23 and 7.24.
Control Parameter
No. Name Min
Service_
7.22 Output_ 0
Control_Mode
0
Service_ 0
7.23
0
Output_ SP
132
2
16
Service_
7.24 2
Output_ DB
1
64
506457−01 05/10
Table 39. Service Relay Options
Control Value
Default Max. Units
0 127 Option
127 255 Counts
996 2000 I:ppm
100 100 P: %
51 −31 Y:DegF
Counts
13 255
102 2000 I:ppm
P: %
13 100
8 162 O:DegF
416 8160 D:Sec.
x x
Y) + (16
Description
A55 Service Output Control Mode = X + 32*Y + 16*Z
Input source = X:
0− None. Standard Service Output based on alarms.
1− Compressor 1 duty cycle. (Compressor crankcase heater function.)
On when OAT < = ECTO 7.23 and >= ECTO 7.24 seconds have passed
with compressor 1 off. Off when OAT > ECTO 7.23 + 3 deg F (fixed dead-
band) or < ECTO 7.24 seconds have passed with compressor 1 off
2− On when occupied.
3− On when blower on,
4− On when heating demand.
5− On when cooling demand.
6− On when heating or cooling demand.
7− System RH (A55_P298_5 RH)
8− System IAQ. (A55_P298_3 IAQ)
9− System OAT (A55_P267_1/2 OAT)
Algorithm Y for input sources 7−9:
0− Hysteresis loop
On when input >= ECTO 7.23
Off when input < ECTO 7.23−ECTO 7.24
1− Window
On when input is in range;
>= ECTO 7.23 and <= ECTO 7.23 + ECTO 7.24
(Fixed 3−count hysteresis loop on rising and
falling edges of window.)
2− Delayed−on.
On when input is >= ECTO 7.23
for >= ECTO 7.24 seconds.
Off when input is < ECTO 7.23−3.
(Fixed 3−count hysteresis loop on edge.)
3− Delayed−off.
On when input is >= ECTO 7.23.
Off when input is < ECTO7.23 − 3
for >= ECTO 7.24 seconds.
(Fixed 3−count hysteresis loop on edge.)
Inversion Z:
0− Output not inverted.
1− Output inverted.
A55 service relay output setpoint.
A55 service relay output deadband or delay.
Page 60
15.
Z) is used to select the option. See table
OFF
7.23−7.24
OFF
7.23
OFF
7.23
OFF
Graphs indicate output not in-
verted. See figure 33.
Service Relay
ON
7.23
ON
OFF
7.23+7.24
ON
Delay
7.24
Delay
7.24 ON
7.23