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Viessmann AirflowPLUS AH2A Technical Data
Electrical Connections
Legend
1
1
Diagnostic LED
2
2
Ambient temperature sensor
3
3
Return air temperature sensor
4
4
Supply air temperature sensor
5
5
Freeze protection temperature sensor
7
7
Supply water temperature sensor
8
8
A/C power
9
9
Pump motor
10 24VAC transformer secondary
10
11
11 24VAC transformer primary
12
12 ECM power
13 ECM control
Legend
AC Line
1 115VAC line
2 115VAC neutral
Pump (PMP)
1 115VAC neutral
2 115VAC line
XFO
1 24VAC
2 N/C
3 24VAC-COM (GND)
XFI
1 115VAC line
2 115VAC neutral
ECM Power
1 N/C
2 N/C
3 N/C
4 115VAC neutral
5 115VAC line
(continued)
ECM Control
1 Common C1
2 W/W1
3 Common C2
4 Delay tap select
5 Cool tap select
6 Y1
7 Adjust tap select
8 Output
9 Return valve (heat pump only)
qP Humidistat (BK)
qQ Heat tap select
qW 24VAC (R)
qE 2nd stage heat (EM/W2)
qR 2nd stage cool (Y/Y2)
qT Fan (G)
qZ Output +
7
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