Sequence Of Operation; Abbreviations - Trane TAMXB0A24V21DB Installation, Operation And Maintenance Manual

Sequence of Operation

T T A A M M X X can be used in either Link Communicating
mode or 24 volt mode. In Link Communicating mode,
all configurations are made by using the configuration
menu in the User Interface (UX360) or from the
Diagnostic Mobile App. In 24 volt mode, basic
operation is configured from the factory with no
defaults for accessories. All configurations for blower
delays, accessories etc., need accomplished using the
Diagnostic Mobile App.

Abbreviations

• AHC = Air Handler Control
• EEV = Electronic Expansion Valve
N N o o t t e e : : When in communicating mode, the system
controller (SC360) controls indoor airflow and
EEV starting position.
N N o o t t e e : : Use variable speed outdoor Sequence of
Operation in conjunction with the TAMX
Sequence of Operation.
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.
S S e e e e u u n n i i t t , , e e l l e e c c t t r r i i c c h h e e a a t t , , a a n n d d f f i i e e l l d d w w i i r r i i n n g g d d i i a a g g r r a a m m s s
f f o o r r a a d d d d i i t t i i o o n n a a l l i i n n f f o o r r m m a a t t i i o o n n . .
C C o o n n t t i i n n u u o o u u s s F F a a n n
I I m m p p o o r r t t a a n n t t : : 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. When a fan request is received from the
thermostat, the AHC sends a command to the serial
communicating blower motor to run. Airflow can be
adjusted through the thermostat.
2. Humidity Control – When enabled at the
thermostat, this feature will disable any blower off
delays and disable continuous fan mode when the
humidity is above the dehumidification set point.
This will help prevent coil condensation from being
evaporated back into the air stream.
C C o o o o l l i i n n g g M M o o d d e e
1. When a request for 1st stage cooling is received,
the AHC sends a command to the serial
communicating blower motor to run at 1st stage
cooling airflow. (Delay profiles found in the UX360
User Interface or Diagnostics Mobile App may
change blower motor timing and actual airflow
demand)
2. The AHC will receive input from the two
temperature sensors and start to control 1st stage
superheat.
64
3. When a request for 2nd stage cooling is received,
the AHC sends a command to the serial
communicating blower motor to run at 100 %
cooling airflow.
4. The AHC will now control superheat for 2nd stage.
5. When a request for cooling is removed, the AHC
will turn off the blower motor after any user
selected fan-off delays have expired.
N N o o t t e e : : Delay profiles found in the UX360 User Interface
or Diagnostics Mobile App may change blower
motor timing and actual airflow demand.
H H e e a a t t p p u u m m p p ( ( c c o o m m p p r r e e s s s s o o r r o o n n l l y y ) )
1. When a request for 1st stage heat is received, the
AHC sends a command to the serial communicating
blower motor to run at 1st stage heating airflow.
2. The AHC will drive the EEV to the heating position
and refrigerant will flow in the reverse cycle.
3. When a request for 2nd stage mechanical heat is
received, the AHC sends a command to the serial
communicating blower motor to run at 100 %
heating airflow.
4. When a request for heat pump is removed, the AHC
will turn off the blower motor after any user
selected fan-off delays have expired.
N N o o t t e e : : Delay profiles found in the UX360 User Interface
or Diagnostics Mobile App may change blower
motor timing and actual airflow demand.
E E l l e e c c t t r r i i c c H H e e a a t t
1. When a request for electric heat is received, the
AHC will energize the on board 24 volt relays per
the amount of heat requested from the thermostat
and the size of the heater installed.
2. The AHC sends a command to the serial
communicating blower motor to run proper airflow
and close the blower interlock relay on the AHC.
H H y y d d r r o o n n i i c c H H e e a a t t
1. When a request for hydronic heat is received, the
AHC will energize the on board W1 relay.
2. The AHC sends a command to the serial
communicating blower motor to run at the
requested CFM.
D D e e f f r r o o s s t t
1. The OD unit will initiate defrost and send a
message to the AHC.
2. The AHC will communicate to the EEV that the OD
is in defrost and the EEV will start to control the
correct superheat.
3. Electric or hydronic heat will be energized to help
temper the air.
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