Fedders F80A, Installation, Operation And Maintenance Manual

13

MODEL F80A

CONVERSIONS

HIGH ALTITUDE

In the United States, the modifications for high altitude are
based on a 4 percent reduction of input capacity for every
1000 feet above sea level. Table 4 on page 14 illustrates the
impact of altitude for selected elevations. Ratings shown
apply to the highest elevation in range. 

Consult with local fuel suppliers or authorities to determine
local regulations or customs.

In Canada, the furnace may be converted for high altitude
(2000 - 4500 feet) by changing the burner orifices. Use Kit No.
30552. The kit contains both natural gas and L.P. gas orifices;
see Table 5 on page 14. *

Model F80A035 is not approved

for LP.

CAUTION

ENSURE THAT THE MANUAL SHUTOFF VALVE AND GAS
VALVE ARE NOT SUBJECTED TO HIGH PRESSURES.

DISCONNECT THE MANUAL SHUTOFF VALVE AND GAS
VALVE DURING ANY PRESSURE TESTING THAT EXCEEDS
1/2 P.S.I.G. (3.45 KPA

).

WARNING

NEVER PURGE A GAS LINE INTO THE COMBUSTION
CHAMBER.

NEVER USE A MATCH, TAPER, CIGARETTE LIGHTER, FLAME
OR ANY OTHER IGNITION SOURCE TO CHECK FOR LEAKS
IN A GAS LINE.

FAILURE TO ADHERE TO THIS WARNING CAN CAUSE A
FIRE OR EXPLOSION RESULTING IN PROPERTY DAMAGE,
PERSONAL INJURY, OR LOSS OF LIFE.

The natural gas inlet supply pressure should be 5 to 7 inches
water column (w.c.), 7 inches w.c. is recommended.

The L.P. gas inlet supply pressure should be 11 to 14 inches
w.c., 12 inches w.c. is recommended.

These pressures must be maintained while all other gas fired
appliances are operating at maximum conditions.

Do not exceed 14 inches w.c. inlet pressure with LP. Do not
exceed 10.5 inches w.c. inlet pressure with NG.

The gas valve has an adjustable internal regulator for
controlling burner manifold pressure. Burner manifold
pressure is listed on the furnace rating plate.

LEAK TESTING

All new gas piping installations should be pressure tested as
specified by CAN/CGA-B149 or NFPA 54 ANSI Z223.1 or
ANSI/NFPA 58, Standard for the Storage and Handling of
Liquefied Petroleum Gases.

Gas piping that has not been pressure tested, from the
manual shutoff valve to the furnace gas valve for example,
should be leak tested using an electronic combustible gas
detector, a commercially prepared leak detector such as Gas
Leak Detector® or Search®, or other locally approved
method. A leak detector solution can be prepared by mixing
a small quantity of dish detergent with water and daubing it
onto the gas piping and connections.

PURGING GAS LINES

NATURAL TO L.P. GAS

This series furnace is manufactured as a natural gas (sea level)
appliance. It may be converted to L.P. gas with the use of Kit
No. 30482 (contact manufacturer for availability). The kit
contains the orifices needed for all models, the regulator
spring for the gas valve, and a label to affix adjacent to the
appliance rating plate to alert subsequent service technicians
of the conversion.

L.P. TO NATURAL GAS

Although the furnace is manufactured initially as a natural gas
appliance, if after an L.P. Gas conversion it becomes necessary
to convert back to natural gas, and if the original parts are
unavailable, Kit No. 30551 may be purchased. It is similar in
nature and content to the L.P. Gas conversion kit.

CONVERSION STEPS

To convert from sea level to high altitude, from natural gas to
L.P. gas, or from L.P. gas to natural gas, follow these steps:
Turn off gas supply to the furnace if applicable.
1.  Shut off electrical power to the furnace if applicable.
2.  Remove the upper front door to expose the gas train and

burner assembly.

3.  Unfasten the ground joint union between the gas valve and

gas supply piping if applicable.

4. Unfasten the burner manifold pipe from the burner

assembly. It is held in place by 2 screws on either end of the
manifold pipe.

5.  Remove the existing orifices with a 7/16 inch socket, box or

openend wrench. Install the replacement orifices. The
orifice spuds are brass, and do not normally require pipe
dope. A light grease may be used to lubricate the threads.
The orifice spuds have tapered threads; do not overtighten
them.
If completing a fuel conversion, remove the protective
screw cap from the gas valve regulator adjustment. Remove
the regulator adjustment screw by turning it
counterclockwise. Remove the existing regulator spring.

6. Install the new regulator spring. NOTE: If converting the

White-Rodgers gas valve, the regulator spring is tapered.
The tapered end (small end) is inserted back into the gas
valve regulator adjustment cavity.
Reinstall the adjustment. Give it 3 full clockwise turns
initially. Do not reinstall the protective screw cap yet.

7.  Reinstall the burner manifold pipe assembly following steps

4, 5, and 6 in reverse order.
If, in all other respects the furnace is ready to be fired,
continue with the installation. If not, complete the
remainder of the installation then return to these steps
before starting the Startup & Setup section.