ClimateMaster Tranquility TCH 024 - Constant Volume ECM Control

ClimateMaster Water-Source Heat Pumps
50
CLIMATEMASTER WATER-SOURCE HEAT PUMPS
Tranquility
®
Compact (TC) Series
Rev.: July 7, 2020
Constant Volume ECM Control
The ECM Constant Volume (CV) blower motor (optional) is
controlled directly by the DXM2 control board that converts
thermostat inputs and CFM settings to signals used by the
ECM-CV motor controller. The DXM2 control must be used
to control the CV ECM motor.
To take full advantage of the ECM-CV motor features, a
communicating multi-stage thermostat should be used
(ATC32U03C). The DXM2 control maintains a selectable
operating airow [CFM] for each heat pump operating
mode. For each operating mode there are maximum
and minimum airow limits. See the ECM-CV Blower
Performance tables for the maximum, minimum, and
default operating airows. Airow levels are selected using
the conguration menus of a communicating thermostat
(ATC32U03C) or conguration/ diagnostic tool (ACDU03C)
and harness 11B0100N27). The conguration menus
allow the installer to independently select and adjust the
operating airow for each of the operating modes. Airow
can be selected in 25 CFM increments within the minimum
and maximum limits shown in the ECM-CV Blower
Performance Table. The blower operating modes include:
• First Stage Cooling (Y1 & O)
• Second Stage Cooling (Y1, Y2, & O)
• First Stage Heating (Y1)
• Second Stage Heating (Y1 & Y2)
• Fan (G with no Y1, Y2, or W)
The ECM-CV 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 efciency. 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 eld selectable by the installer. The
allowable range is 0 to 255 seconds.
ATC Communicating
Thermostat
CV ECM
Blower
Motor
Diagnostic
Tool
AIRFLOW SELECTION
CFM
HEAT STAGE 1 600
HEAT STAGE 2 750
AUXILIARY HEAT 850
EMERGENCY HEAT 850
COOL STAGE 1 525
COOL STAGE 2 700
COOL DEHUMID 1 425
COOL DEHUMID 2 550
CONTINUOUS FAN 350
HEAT OFF DELAY 60
COOL OFF DELAY 30
PREVIOUS NEXT
Airow Conguration Screen on Communicating
Thermostat or (ACDU) Service Tool.
DXM2