Installation and Maintenance Manual

ECM Overview and Setup
UNT-SVX07D-EN 65
Use of Potentiometer/Rheostat For VSP
A courtesy 10-Vdc supply is provided that can support a
10-mA draw. The use of a 1K or a 10K potentiometer is
recommended, and only a stand-alone potentiometer (not
shared with any other electrical system) should be
employed. When a simple potentiometer is used as
depicted in Figure 29, the
 setting will define a null-
zone (off).
The typical connection is depicted in Figure 29; however,
please consult the unit schematic for the most updated
instruction, as Figure 29 is provided as reference only.
Adjustment or Disabling of Optional Auto-
Changeover Function on CSTI Units
WARNING
Hazardous Voltage w/Capacitors!
Disconnect all electric power, including remote
disconnects and discharge all motor start/run
capacitors before servicing. Follow proper lockout/
tagout procedures to ensure the power cannot be
inadvertently energized. For variable frequency drives
or other energy storing components provided by Trane
or others, refer to the appropriate manufacturer’s
literature for allowable waiting periods for discharge of
capacitors. Verify with an appropriate voltmeter that all
capacitors have discharged. Failure to disconnect
power and discharge capacitors before servicing could
result in death or serious injury.
WARNING
Safety Alert!
You MUST follow all recommendations below. Failure
to do so could result in death or serious injury.
• The adapter boards contain high voltage.
Connections to the adapter boards/changes to the
CSTI configuration switches should be made only
with the power to the unit disconnected.
• Configuration adjustments to the ECM engine board
should be made through the SMALLER of the two
low-voltage lids on the front of the control panel,
through the low-voltage insulation/shielding.
• All settings take effect immediately, including fan
startup, enabling of electric heat. Caution should be
taken to stay clear of hazardous voltages, moving
parts and electric heat elements while making
adjustments to the ECM engine board. If it is not
practical to stay clear of these areas during
adjustment of the ECM engine board, please contact
Trane Global Parts for configuration kit that allows
easy powering of the engine board outside of the unit
with a 9V battery.
Figure 29. Typical connection
WARNING
Hazardous Voltage w/Capacitors!
Disconnect all electric power, including remote
disconnects and discharge all motor start/run
capacitors before servicing. Follow proper lockout/
tagout procedures to ensure the power cannot be
inadvertently energized. For variable frequency drives
or other energy storing components provided by Trane
or others, refer to the appropriate manufacturer’s
literature for allowable waiting periods for discharge of
capacitors. Verify with an appropriate voltmeter that all
capacitors have discharged. Failure to disconnect
power and discharge capacitors before servicing could
result in death or serious injury.
WARNING
Safety Alert!
You MUST follow all recommendations below. Failure
to do so could result in death or serious injury.
• The adapter boards contain high voltage.
Connections to the adapter boards should be made
only with the power to the unit disconnected.
• All settings take effect immediately, including fan
startup, enabling of electric heat. Caution should be
taken to stay clear of hazardous voltages, moving
parts and electric heat elements while making
adjustments to the ECM engine board. If it is not
practical to stay clear of these areas during
adjustment of the ECM engine board, please contact
Trane Global Parts for configuration kit that allows
easy powering of the engine board outside of the unit
with a 9V battery.
UNT-SVX07_-EN.book Page 65 Friday, April 27, 2012 9:40 AM