48
18-GJ06D2-2A
TAM7 Sequence of Operation
Abbreviations
•
AFC = Airflow Control
•
EVC = Expansion Valve Control
•
EEV = Electronic Expansion Valve
•
EHC = Electric Heat Control
•
HHC= Hydronic Heat Control
•
Y1 = Y Signal from the comfort control
•
YO = Y Signal out of the AFC from the comfort
control
•
Y2 = Y2 Signal from comfort control
This unit has a unique feature that receives 24VAC
analog inputs from a conventional comfort control and
then converts these inputs to serial communicating
signals between the different controls within the air
handler.
The installing and servicing technician should have an
understanding of the sequence of operation to be able
to properly setup and diagnose functions of the air
handler.
The dip switch settings on the control boards must be
properly set to obtain the correct sequence of
operation. Reference the air handler and electric heat
wiring diagrams and dip switch configuration chart for
additional information.
S
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C
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uss F
Fa
an
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IIm
mp
po
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ntt:: If the indoor air exceeds 60% relative
humidity or simply feels uncomfortably
humid, it is recommended that the indoor
fan only be used in the AUTO mode.
1.
R-G contacts close on comfort control sending
24VAC to the G terminal of the AFC.
2. The AFC micro-processor sends a command to the
serial communicating blower motor to run at 50%.
See airflow Dip Switch settings for additional info.
H
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att p
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p O
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1.
R-Y contacts close on the comfort control sending
24VAC to Y1 terminal on the AFC.
2. Normally closed contacts on the AFC will pass
24VAC to the YO terminal providing power to the
outdoor unit control circuit.
3. R-G contacts close on comfort control sending
24VAC to the G terminal of the AFC.
4. The AFC micro-processor sends a command to the
serial communicating blower motor to run at 100%.
5. The HUM contacts close.
H
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att p
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um
mp
p O
OD
D T
Tw
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e ((h
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1.
R-Y contacts close on the comfort control sending
24VAC to Y1 terminal on the AFC.
2. Normally closed contacts on the AFC will pass
24VAC to the YO terminal providing power to the
outdoor unit 1st stage control circuit.
3. R-G contacts close on comfort control sending
24VAC to the G terminal of the AFC.
4. The AFC micro-processor sends a command to the
serial communicating blower motor to run at 1st
stage heating cfm.
5. The HUM contacts close.
6. R-Y2 contacts close on the comfort control sending
24VAC to Y2 terminal on the AFC.
7.
The Y2 signal is also passed through to provide
power to the outdoor unit 2nd stage control circuit.
8. The blower motor will now run at 100% of the
heating cfm.
O
OD
D S
Siin
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glle
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oo
olliin
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g m
mo
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1.
R-Y contacts close on the comfort control sending
24VAC to Y1 terminal on the AFC.
2. Normally closed contacts on the AFC will pass
24VAC to the YO terminal providing power to the
outdoor unit control circuit.
a. Heat pump OD > R-O contacts close on the
comfort control sending 24VAC to the O
terminal of the AFC. The AFC communicates to
the EVC that the system is in cooling mode. The
O signal is passed through to the OD unit.
b. Non heat pump OD > OD dip switch
configuration will communicate to the EVC to
control superheat on a Y only signal.
3. R-G contacts close on comfort control sending
24VAC to the G terminal of the AFC.
4. The AFC micro-processor sends a command to the
serial communicating blower motor to run at 100%
of the cooling cfm.
5. The EVC will receive input from the two
temperature sensors and start to control superheat.
