Installation Manual

24
RCYGW
STATUS
FLAME
GREEN
RED
180
COOL
HEAT
120
90
60
YELLO
W
BLOWER
OFF
DELAY
LOW
ML
MH
HIGH
EAC
L1
XFMR
HUM
COM
SPEED
SELECT
3 AMP
FUSE
24V
5
NEUTRALS
ROOM
THERMOSTAT
A/C CONDENSING UNIT
CONDENSING UNIT
CONTROL BOX
EXPANSION PORT
(MOTOR CONNECTION)
FIELD WIRING LOW
VOLTAGE CONNECTION
R
C
Y
G
W
NO
TE: The “Y” terminal on the
control
board must be connected
to the ther
mostat for proper
cooling mode operation.
2
ELECTRONIC
AIR CLEANER
HUMIDIFIER TAP
NEUTRAL LEADS
63
4
1
7
8
9
5
2
63
4
1
FAN
Connect R & W
For Heating
Only
Figure 22. Low Voltage Field, Four-wire
Heating/Cooling Applications
Start-up Procedures
Do not perform these steps until all of the checks in the
previous steps have been completed:
1. Set the thermostat to the lowest setting.
2. Turn off all electrical power to the furnace.
3. Follow the Operating Instructions on the label attached
to the furnace.
4. Set the thermostat above room temperature and verify
the Operating Sequence (page 25).
5. After 5 minutes of operation, set the thermostat below
room temperature and verify steps 9 - 10 of the Operating
Sequence.
Verifying Input Rate
The input rate must be verified for each installation to
prevent over-firing of the furnace. NOTE: The input rate
must not exceed the rate shown on the furnace rating plate.
At altitudes above 2,000 feet, it must not exceed that on
the rating plate less 4% for each 1,000 feet. To determine
the exact input rate, perform the following procedures:
1. Shut off all other gas fired appliances.
2. Start the furnace and run it for at least 3 minutes.
3. Measure the time (in seconds) required for the gas
meter to complete one revolution.
4. Convert the time per revolution to cubic feet of gas per
hour using Table 7, (page 34).
5. Multiply the gas flow rate in cubic ft per hr by the heating
value of the gas in Btu per cubic ft to obtain the input
rate in Btuh. See example above.
Verifying & Adjusting Temperature Rise
After installation of the furnace, confirm the temperature
rise of the furnace is within the limits specified on the rating
plate. Any temperature rise outside the specified limits
could result in premature failure of the heat exchanger.
For typical duct systems, the temperature rise will fall
within the limits specified on the rating plate with the
blower speed at the factory recommended setting. If the
measured temperature rise is outside the specified limits,
it may be necessary to change the speed of the blower.
NOTE: Lowering the blower speed will increase the
temperature rise and a higher blower speed will decrease
the temperature rise.
The furnace is equipped with an ECM motor. Heating and
cooling speed selection is made by moving the switch on
the integrated control located in the furnace. The furnace is
shipped from the factory pre-wired for four blower speeds.
There is a fifth alternate speed available on the motor. To
utilize the alternate speed, remove the wire at the motor
plug of the desired speed to be changed (H, MH, ML, L).
Example:
• Time for 1 revolution of a gas meter with a 1 cubic
ft dial = 40 seconds.
• From Table 8 read 90 cubic ft gas per hr.
• Local heating value of the gas (obtained from gas
supplier) = 1,040 Btu per cubic ft.
• Input rate = 1,040 x 90 = 93,600 Btuh.
Grounding
WARNING:
To minimize personal injury, the furnace cabinet
must have an uninterrupted or unbroken electrical
ground. The controls used in this furnace require
an earth ground to operate properly. Acceptable
methods include electrical wire or conduit
approved for ground service. Do not use gas
piping as an electrical ground!
START-UP & ADJUSTMENTS
Pre-Start Check List
√ Verify the polarity of the connections are correct, the
line voltage power leads are securely connected and
the furnace is properly grounded.
√ Verify the thermostat wires (R, W, Y, & G) are securely
connected to the correct leads on the terminal strip of
the circuit board.
√ Verify the gas line service pressure does not exceed 10.0
inches of W.C., and is not less than 4.5 inches W.C. for
natural gas. For LP gas the line service pressure must
not exceed 14 in. W.C., and must not be less than 11.0
in. W.C.
√ Verify the roll-out and vent switches are closed. If
necessary, press the red button to reset a switch. DO
NOT install a jumper wire across a switch to defeat
its function. If a switch reopens on startup, DO NOT
reset the switch without identifying and correcting
the fault condition.
√ Verify the blower door is in place, closing the door switch
in the line voltage circuit.
√ Verify the gas line has been purged and all connections
are leak free.