Trane 090A***A - 60 HZ, Installation Owner Diagnostics

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22 SS-SVN11A-EN
Unit Start-Up
Once the unit is properly installed and
pre-start procedures
are complete, start the unit by turning
the System Switch on the indoor ther-
mostat to either HEAT, COOL or AUTO.
The system should operate normally.
Sequence of Operation
General
Operation of the system cooling (and
optional heating) cycles is controlled
by the position of the system switch
on the room thermostat. Once the
system switch is placed in either the
HEAT or COOL position, unit opera-
tion is automatic. The optional auto-
matic changeover thermostat, when
in the
AUTO position, automatically
changes to heat or cool with sufficient
room temperature change.
Evaporator Fan (Indoor Supply
Air)
The evaporator fan is controlled by an
ON/AUTO switch on the room ther-
mostat. With the switch positioned at
AUTO and the system operating in
the cooling mode, fan operation coin-
cides with the cooling run cycles. If
the system is equipped with heat and
is operating in the heating mode
while the fan switch is at
AUTO , fan
operation coincides with the heating
run cycles. When the fan switch is
positioned at
ON, fan operation is
continuous.
Cooling Mode
When the room thermostat system
switch is positioned at
COOL and the
fan switch is at AUTO , the condenser
fan relay energizes on a call for cool-
ing. When the contacts of the con-
denser fan relay close, operation of
the condenser fan begins. The evapo-
rator fan contactor also energizes on a
call for cooling and initiates evapora-
tor fan operation.
On units with dual circuits, the second
stage of cooling is initiated as a result
of the 2-stage thermostat calling for
additional cooling.
System
Pre-Start Procedure