Sequence Of Operation - Trane 4YCC4024E1060A Installation And Operation Manual

2. Purge the gas supply line of air by opening the
union ahead (upstream) of the unit. When the odor
of gas is detected, retighten the union and wait five
(5) minutes before proceeding.
3. Be sure the thermostat is at its lowest setting and
the power to the unit is off.
a. Turn the main shut-off valve on the gas supply
line to ON.
b. Turn the thermostat to the highest setting in the
heating cycle.
4. 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.
5. 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.
N N o o t t e e : : For manifold pressures and orifice sizes
for gas with other BTU ratings, contact
the local gas utility. Manifold pressure
should be 3.5 inches w.c. (+0.1). Input
must n n o o t t exceed the value shown on the
rating plate.
e. With the burner operating, check the manifold
pressure with a manometer.
6. Do not exceed recommended pressures. If the
manifold pressure needs adjustment, refer to
Manifold Pressure Check and Adjust in the
Maintenance section. With the burners operating,
check the manifold pressure with a manometer.
7. If necessary, adjust the unit to obtain an air
temperature rise with that specified on the unit
nameplate. To adjust, refer to the Indoor Fan Motor
Speed Adjustment in the Maintenance section.
N N o o t t e e : : 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.
8. Set the thermostat at the desired temperature
setting and the unit will function automatically.
18-EB40D1-1E-EN

Sequence of Operation

G G e e n n e e r r a a l l
Operation of the system cooling (and optional heating)
cycles is controlled by the setting of the system switch
on the room thermostat. Once the system switch is
placed either in the "HEAT" or "COOL" position, unit
operation is automatic. A fan switch on the thermostat
also provides for continuous operation of the
evaporator fan when desired. The fan switch "ON"
position provides continuous operation while the
"AUTO" position provides operation during the
heating or cooling cycles.
H H e e a a t t i i n n g g C C y y c c l l e e
T T h h e e r r m m o o s s t t a a t t c c a a l l l l f f o o r r h h e e a a t t
(R) and (W) thermostat contacts close signaling the
control module (IGN) to run its self-check routine. After
the control has verified that the pressure switch (PS)
contacts are open, the limit switch (TCO) contacts are
closed, and the flame rollout (RO) switch is closed, the
induced draft blower (CFM) will be energized.
After the induced draft blower (CFM) has come up to
speed, the control will verify that the pressure switch
(PS) contacts are closed and run the induced draft
blower for a 20 second pre-purge. The gas valve (GV) is
energized to permit gas flow and the spark ignitor (IP)
is energized. The flame detector (FD) confirms that
ignition has been achieved within the 7 second trial
period.
As the flame detector confirms that ignition has been
achieved the delay to indoor fan on period begins
timing and after approximately 45 seconds, the indoor
blower motor (IDM) will be energized and will continue
to run during the heating cycle
T T h h e e r r m m o o s s t t a a t t s s a a t t i i s s f f i i e e d d :
(R) and (W) contacts open signaling the control module
to close the gas valve and de-energize the induced draft
blower after approximately 5 seconds post-purge. The
indoor blower motor will continue to operate at the
current speed for 60 or 90 seconds (field selectable)
after the flames are extinguished.
C C o o o o l l i i n n g g C C y y c c l l e e
With the room thermostat system switch in the
"COOLING" position and the fan switch in the "AUTO"
position, the compressor contactor (CC) and the indoor
fan motor (IDM) are energized.
The energized compressor contactor (CC) completes
the circuit to the compressor (CPR) and a secondary
circuit to the outdoor fan motor (ODM). If the
compressor safety controls are closed, the compressor
(CPR) will operate with the outdoor fan motor (ODM).
The indoor fan motor (IDM) will operate. The
thermostat will continue to cycle the compressor and
fans to maintain the desired temperature.
With the thermostat fan switch in the "ON" position, the
indoor fan motor (IDM) will continue to run at constant
U U n n i i t t S S t t a a r r t t u u p p
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