System Prestart Procedure - Trane TTA240F Series Installation Operation & Maintenance

Safety Controls
Note: All of these controls may not
be installed on your unit,
check electrical schematic.
Low Outdoor Ambient Cooling
The Evaporator Defrost Control is
standard equipment on Air Handlers
and will permit low ambient cooling
down to 50 degrees F . For cooling
operation down to 0 degrees F , use an
Accessory Head Pressure Control on
the outdoor unit.
Evaporator Defrost Control (EDC)
This control is located in the Air
Handler of Split Units. The control's
sensing tube is imbedded vertically in
the evaporator coil, near the center.
This device will stop the compressor if
the indoor coil temperature drops
below its setting. The indoor air will
still circulate across the coil bringing
the temperature of the coil back up to
the cut-in temperature of the
evaporator defrost control.
Low Pressure Cut-Out (LPCO)
This control's sensor is located in the
suction (gas) line, near the
compressor. This control will stop the
compressor and the outdoor fans if
suction pressure drops below the Low
Pressure Cut-Out setting. Once the
suction pressure has returned to
normal, the compressor and outdoor
fans will cycle back on.
High Pressure Cut-Out (HPCO)
This control's sensor is located in the
discharge line. This device will shut
off the compressor and the outdoor
fan(s) if the discharge pressure
exceeds the High Pressure Cut-Out's
setting. Once the discharge pressure
has returned to normal, the
compressor will cycle back on.
TTA-SVN03A-EN
System Pre-Start Procedure
Internal Overload Protector (IOL)
This device is a thermal actuated snap
disc, imbedded in the compressor. It
will shut off the compressor if the
discharge temperature of the
compressor exceeds its design trip
temperature.
Note: The IOL will put the
compressor back in operation
once the compressor motor
heat has dropped below the
trip setting; however, a check
of the refrigerant and
electrical systems should be
made to determine the cause
and be corrected.
Installation Checklist
Complete this checklist once the unit
is installed to verify that all
recommended procedures have been
accomplished before starting the
system. Do not operate the system
until all items covered by this checklist
are complete.
[ ] Inspect unit location for proper
required service clear-ances.
[ ] Inspect unit location for proper free
air clearances.
[ ] Inspect unit location for secure,
level mounting position.
[ ] Performed initial leak test?
[ ] Connected properly sized and
constructed liquid and suction lines to
the connection stubs at both the
indoor and outdoor units?
[ ] Insulated the entire suction line?
[ ] Insulated portions of liquid line
exposed to extremes in temperature?
[ ] Evacuated each refrigerant circuit
to 350 microns?
[ ] Charged each circuit with proper
amount of R410A?
Electrical Wiring
[ ] Provided unit power wiring (with
disconnect) to proper terminals in the
unit control section?
[ ] Installed system indoor
thermostat?
[ ] Installed system low voltage
interconnecting wiring to proper
terminals of outdoor unit, indoor unit
and system thermostat?
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