Nordyne TA-060C-08A, Installation Instructions Manual

32

4. Convert the time per revolution to cubic feet of

gas per hour using Table 11.

5. Multiply the gas flow rate in cubic feet per hour

by the heating value of the gas in Btu per cubic
foot to obtain the firing rate in Btu per hour.
Example:

• Time for 1 revolution of a gas meter with a 1

cubic  foot dial = 40 seconds.

• From Table 11 read 90 cubic feet per hour

of gas.

• Heating value of the gas (obtained from gas

supplier) = 1040 Btu per cubic foot.

• Firing rate = 1040 x 90 = 93,600 Btuh.

6. Adjustments to the firing rate can be made by

adjusting the gas manifold pressure. See the
High Altitude Application  section for additional
information of firing rate at elevations above
2000 ft.

The manifold pressure must be set to the
appropriate value for your installation.  Refer to
either Table 6 for natural gas or Table 7 for LP/
propane gas to verify the manifold pressure
setting required for your particular installation.
To adjust the manifold pressure, remove the
regulator cap and turn the adjusting screw
clockwise to increase pressure or counter-
clockwise to reduce pressure. Replace the
regulator cap after adjustments are complete.

!  CAUTION:

Do not re-drill the burner orifices. If the
orifice size must be changed, use only
new orifices.

Verifying and Adjusting Temperature Rise

Verify  the temperature rise through the furnace
is within the range specified on the furnace
rating plate. Temperature rises outside the
specified range could result in premature heat
exchanger failure.

Place thermometers in the return and supply air
stream as close to the furnace as possible.  The
thermometer on the supply air side must be
shielded from direct radiation from the heat
exchanger to avoid false  readings. Adjust all
registers and duct dampers  to  the  desired
position   and  run  the furnace for ten to fifteen
minutes before taking any temperature read-
ings. The temperature rise is the difference
between the supply and return air tempera-
tures. For typical duct systems, the tempera-
ture rise will fall within the range specified on the
rating plate with the blower speed at the factory
recommended setting.  If the temperature rise
measured is outside the range specified, it may
be necessary to change the blower speed.
Lower blower speeds will increase the tem-
perature rise and higher blower speeds will
decrease the temperature rise. The furnace is
equipped with a multi-speed motor.  Heating and
cooling speed selection is made by moving the
leads located in the furnace (See Figure 33
blower relay). The wiring diagram on the fur-
nace and Figure 35 show the speed taps for
adjusting motor speed.

If it is desired that the blower operate at the same
speed for heating and cooling, tape off the
unused blower lead and install the jumper wire.
The jumper wire should be connected between
the “cool” terminal on the control board and the

YELLOW

YELLOW

C

H

MH

ML

L

1

2

3

4

5

6

3 OR 4 SPEED

MOTOR

RED

ORANGE

BLUE

BLACK

WHITE

INTEGRATED

CONTROL BOARD

6 PIN

PLUG

2

4

5

6

N.O

N.C

24V

1

3

DPST

RELAY

LI

XFMR

EA
C

COOL

HEA

T

M3

M2

M1

HUM

Figure 33. Blower Relay