Nordyne *SA Upfl ow / Horizontal, Installation Instructions Manual

Page: 21 / 36

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6. The manifold pressure must be set to the appropriate
value for each installation by a qualifi ed installer, service
agency or the gas supplier.
WARNING:
Do not attempt to drill the gas orifi ces. Use only
factory supplied orifi ces. Improperly drilled
orifi ces may cause fi re, explosion, carbon
monoxide poisoning, personal injury or death.
a.) Obtain the manifold pressure setting required for
this installation by referring to Table 8 (page 32) for
Propane or Tables 10 or 11 for Natural Gas (page
33).
b.) Remove the regulator capscrew (Figure 17,
page 22) from the INLET side of the regulator.
c.) Slowly turn the adjustment screw inside the regulator
to obtain the appropriate manifold pressure.
NOTE: Turning the screw clockwise increases
the pressure and turning the screw counter-
clockwise decreases the pressure. To prevent
backing the screw all the way out from the valve,
turn the screw slowly.
d.) Replace and tighten the regulator capscrew over
the adjustment screw.
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 manual reset switch is 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.
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 22).
5. After 5 minutes of operation, set the thermostat
below room temperature and verify steps 9 - 10 of
the Operating Sequence.
Example :
• Time for 1 revolution of a gas meter with a 1 cubic
ft dial = 40 seconds.
• From Table 6 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.
Verifying & Adjusting Input Rate
The input rate must be verifi ed for each installation to
prevent over-fi ring 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 fi red 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 6 (page 31).
5. Multiply the gas fl ow 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.
NOTE: One furnace can be used for one stage of heating
and the other furnace can be used for the second stage of
heating. The installer also has the choice of running one
furnace only or both furnaces. In both cases the blowers
will run at the same time and at the same speeds:
• Single stage heating: The
W connection on each furnace
must be connected together and then connected to the
W connection of the thermostat. This will allow both
furnaces to ignite at the same time for one stage heating.
• Two stage heating: The W connection on one furnace
must be connected to the W1 connection of the
thermostat. The W connection of the second furnace
must be connected to the W2 connection of the
thermostat. This will allow one furnace to ignite for one
stage of heating and the second furnace to ignite for
the second stage of heating.
3. Refer to Figure 16 (page 20) for the remaining
thermostat connections. The C connection must be
made between the twinned furnaces to ensure proper
performance.