ANGLE IRON |
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BRACKET |
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FIGURE 6: Typical Suspended Furnace / Crawl Space Installation
In any application where temperatures below freezing are possible,
EXTERNAL MANUAL
SHUTOFF VALVE
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| GROUNDED JOINT UNION |
DRIP |
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LEG |
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FIGURE 8: Downflow Gas Piping
MANUAL
VALVE
see “BELOW FREEZING LOCATIONS”.
GAS PIPE
DRIP LEG
SECTION IV: GAS PIPING
GAS SAFETY
GAS PIPE
GAS BURNERS
GAS VALVE
An overpressure protection device, such as a pressure regulator, must be installed in the gas piping system upstream of the furnace and must act to limit the downstream pressure to the gas valve so it does not exceed 0.5 PSI {14" w.c. (3.48 kPa)}. Pressures exceed- ing 0.5 PSI {14” w.c. (3.48 kPa)} at the gas valve will cause damage to the gas valve, resulting in a fire or explosion or cause damage to the furnace or some of its components that will result in property damage and loss of life.
DRIP | MANUAL |
LEG |
FIGURE 9: Horizontal Gas Piping
IMPORTANT: An accessible manual shutoff valve must be installed upstream of the furnace gas controls and within 6 feet (1.8 m) of the fur- nace.
The furnace must be isolated from the gas supply piping system by closing its individual external manual shutoff valve during any pressure testing of the gas supply piping system at pressures equal to or less
OUTLET
PRESSURE
PORT
INLET
WRENCH BOSS
INLET PRESSURE PORT
| VENT PORT |
| OUTLET |
OFF |
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ON | MAIN REGULATOR |
ON/OFF SWITCH | ADJUSTMENT |
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(Shown in ON position) |
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than 1/2 psig (3.5 kPa).
Never apply a pipe wrench to the body of the gas valve when installing piping. A wrench must be placed on the octagonal hub located on the gas inlet side of the valve. Placing a wrench to the body of the gas valve will damage the valve causing improper oper- ation and/or the valve to leak.
FIGURE 7: Gas Valve
IMPORTANT: Plan your gas supply before determining the correct gas pipe entry. Use
GAS PIPING INSTALLATION
Properly sized wrought iron, approved flexible or steel pipe must be used when making gas connections to the unit. If local codes allow the use of a flexible gas appliance connection, always use a new listed con- nector. Do not use a connector that has previously serviced another gas appliance.
Some utility companies or local codes require pipe sizes larger than the minimum sizes listed in these instructions and in the codes. The furnace rating plate and the instructions in this section specify the type of gas approved for this furnace - only use those approved gases. The instal- lation of a drip leg and ground union is required. Refer to Figure 8.
Gas piping may be connected from either side of the furnace using any of the gas pipe entry knockouts on both sides of the furnace. Refer to Figure 3 dimensions.
GAS ORIFICE CONVERSION FOR PROPANE (LP)
This furnace is constructed at the factory for natural
HIGH ALTITUDE GAS ORIFICE CONVERSION
This furnace is constructed at the factory for natural
The manifold pressure must be changed in order to manitain proper and safe operation when the furnace is installed in a location where the altitude is greater than 8,000 feet (2,438 m) above sea level. Refer to to Table 6 for proper manifold pressure settings.
HIGH ALTITUDE PRESSURE SWITCH CONVERSION
For installation where the altitude is less than 8,000 feet (2,438 m), it is not required that the pressure switch be changed. For altitudes above 8,000 feet (2,438 m), see Field Installed Accessories - High Altitude pressure Switch.
Unitary Products Group | 9 |
