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c l i m a t e m a s t e r. c o m
T H E S M A R T S O L U T I O N F O R E N E R G Y E F F I C I E N C Y
Tr a n q u i l i t y
®
2 2 ( T Z ) S e r i e s
R e v i s e d : 0 1 / 2 1 / 1 3
ECM Blower Control
The ECM fan is controlled directly by the DXM2 control
board that converts thermostat inputs and CFM settings
to signals used by the ECM motor controller. To take full
advantage of the ECM motor features, a communicating
multi-stage thermostat should be used (ATC32U**).
The DXM2 control maintains a selectable operating
airfl ow [CFM] for each heat pump operating mode. For
each operating mode there are maximum and minimum
airfl ow limits. See the ECM Blower Performance tables
for the maximum, minimum, and default operating
airfl ows.
Airfl ow levels are selected using the confi guration menus
of a communicating thermostat (ATC32U**) or diagnostic
tool (ACDU**). The confi guration menus allow the
installer to independently select and adjust the operating
airfl ow for each of the operating modes. Air fl ow can be
selected in 25 CFM increments within the minimum and
maximum limits shown in the ECM Blower Performance
Table. The blower operating modes include:
• First Stage Cooling (Y1 & O)
• Second Stage Cooling (Y1, Y2, & O)
• First Stage Cooling in Dehumidification Mode
(Y1, O, & Dehumid)
• Second Stage Cooling in Dehumidification Mode
(Y1, Y2, O, & Dehumid)
• First Stage Heating (Y1)
• Second Stage Heating (Y1 & Y2)
• Third Stage (Auxiliary) Heating (Y1, Y2, & W)
• Emergency Heating (W with no Y1 or Y2)
• Fan (G with no Y1, Y2, or W)
It is highly recommended that ATC32U** or ACDU**
be used to set dehumidifi cation mode electronically.
Dehumidifi cation can NOT be selected when using a
non-communicating thermostat with a vFlow™ unit with
Internal Flow Controller (pump). For dehumidifi cation
settings on other units using the non-communicating
stat, refer to DXM2 AOM (part #97B0003N15).
The ECM motor includes “soft start” and “ramp down”
features. The soft start feature is a gentle increase of
motor rpm at blower start up. This creates a much quieter
blower start cycle.
The ramp down feature allows the blower to slowly
decrease rpm to a full stop at the end of each blower
cycle. This creates a much quieter end to each blower
cycle and adds overall unit effi ciency.
Special Note for AHRI Testing:
To achieve rated airfl ow for AHRI testing purposes, it is
necessary to change the CFM settings to rated airfl ow.
The ramp down feature is eliminated during an ESD
(Emergency Shut Down) situation. When the DXM2
ESD input is activated, the blower and all other control
outputs are immediately de-activated.
The ramp down feature (also known as the heating or
cooling “Off Delay”) is fi eld selectable by the installer.
The allowable range is 0 to 255 seconds.
