Trane 4YCY4042C, Installer'S Manual

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Page 22
Installer’s Guide

Does the unit run and operate as described in the section on
Sequence of Operation in response to the room thermostat?

Are the condenser fan and indoor blower operating correctly
with proper rotation and without undue noise?

Is the compressor operating correctly and has the system been
checked with a charging chart?

Has the voltage and running current been checked to deter
mine if it is within limits?

Has the thermostat been checked for calibration and the air
discharge grilles adjusted to balance the system?

Has the ductwork been checked for air leaks and
condensation?

Has the furnace manifold pressure been checked and
adjusted if necessary?

Has the heating air temperature rise been checked?

Has the unit been checked for tubing and sheet metal rattles?
Are there any other unusual noises to be checked?

Are all covers and panels in place and properly fastened?

Has the owner been instructed on the proper operation and
maintenance of the unit? Be sure to leave this manual with the
owner.
Final Installation Checklist
Starting the Unit in the Cooling Mode
To start the unit in the cooling mode, set the thermostat system switch
to COOL and move the thermostat COOL indicator to a setting below
room temperature. The condenser (outdoor) fan motor compressor
and evaporator (indoor) fan motor will operate automatically.
NOTE: See the section on “Sequence of Operation” for a de-
scription of the cooling operating sequence.
Operating Pressures
After the unit has operated in the cooling mode for a short period of
time, install pressure gauges on the gauge ports of the discharge
and suction line valves. Check the suction and discharge pressures
and compare them to the normal operating pressures provided in
the unit’s
SERVICE FACTS.
NOTE: Do not use the pressures from the unit's SERVICE FACTS
to determine the unit refrigerant charge. The correct charge is
shown on the unit nameplate. To charge the system accurately,
weigh in the charge according to the unit nameplate.
Voltage
With the compressor operating, check the line voltage at the unit.
The voltage should be within the range shown on the unit name-
plate. If low voltage is encountered, check the size and length of
the supply line from the main disconnect to the unit. The line may
be undersized for the length of the run.
Cooling Shut Down
Set the system mode to OFF or adjust the cooling setpoint to above
room temperature.
Heating Cycle
These units are equipped with a solid-state ignition control that lights
the burners each time the thermostat calls for heat. The burners
are extinguished during the OFF cycle.
The gas heating section of the unit can be started using the follow-
ing procedure:
1. Be sure the thermostat is at its lowest setting and the power to
the unit is off.
a. Turn the main shutoff valve on the gas supply line ON.
b. Turn or switch the manual valve on the combination gas valve
ON position.
2. Be sure the burner compartment access panel is in place.
a. Turn on the electrical power to the unit.
b. Turn the thermostat to the highest setting in the heating cycle.
3. As the thermostat calls for heat, the system cycles as follows:
a. The combustion blower is energized.
b. The pressure switch is closed.
c. The gas valve opens and the ignitor lights the burner.
d. Cycle the thermostat on and off a few times to check out the
control system and burner operation characteristics.
4. With the burners operating, check the manifold pressure with
a manometer. Do not exceed recommended pressures.
5. Adjust the unit to obtain an air temperature rise within the range
that is specified on the unit nameplate.
NOTE: For manifold pressures and orifice sizes for gas with
other BTU ratings, contact the local gas utility. Manifold pressure
should be 1.8 (low) to 3.5 (high) inches water column (+0.1).
Input must
not exceed the value shown on the unit nameplate.
6. Set the heat anticipator of the thermostat to equal the amperage
draw of the gas valve, approximately 0.7.
7. Set the thermostat at the desired temperature setting and the
unit will function automatically.
Starting the Unit in the Gas Heating Mode
1. Check to make sure all grilles and registers are open and all
unit access doors are closed before start-up.
2. Purge the gas supply line of air by opening the union ahead of
the unit. When the odor of gas is detected, retighten the union
and wait five (5) minutes before proceeding.
3. Set the wall thermostat to its lowest position and place the fan
switch in the AUTO or ON position.
4. Open the main gas valve(s) and turn on the unit power supply.
5. Reset the heating temperature lever on the room thermostat
at the highest value above room temperature. The combustion
blower motor should energize. The main burners should light
within 20-25 seconds. Initial start may be delayed somewhat if
the unit has not been purged and air is trapped in the gas line.
NOTE: Blue smoke produced by the heat exchanger during the
initial burner firing is caused by a thin film of oil on the surface
of the heat exchanger. This oil will burn off quickly.