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The gas supply line can approach the unit in three ways:
horizontally from outside the unit (across the roof), thru-
curb/under unit basepan (accessory kit required), or through
unit basepan (factory option or accessory kit required). Con-
sult accessory kit installation instructions for details on
these installation methods. Observe clearance to gas line
components per Fig. 15.
9" MINIMUM CLEARANCE
FOR PANEL REMOVAL
MANUAL GAS
SHUTOFF VALVE
BASE UNIT
48" MINIMUM
BASE RAIL
ROOF
CURB
FROM
GAS
METER
LEGEND
National Fuel Gas
NFGC —
Code
STEEL PIPE NOMINAL
DIAMETERS (IN.)
1
/
2
3
/
or 1
4
1-
1
/
or larger
4
Fig. 15 — Gas Piping Guide
(with Accessory Thru-the-Curb Service Connections)
FACTORY-OPTION THRU-BASE CONNECTIONS
(GAS CONNECTIONS) — This service connection kit
consists of a
1
/
-in. NPT gas adapter fitting (brass), a
2
electrical bulkhead connector and a
head connector, all factory-installed in the embossed
(raised) section of the unit basepan in the condenser section.
See Fig. 16.
BRASS FITTING FOR 3 TO 6 TON UNITS.
Fig. 16 — Thru-Base Gas Connection Fittings
The thru-base gas connector has male and female
threads. The male threads protrude above the basepan of the
unit; the female threads protrude below the basepan.
Check tightness of connector lock nuts before connecting
gas piping.
Install a
1
/
-in. NPT street elbow on the thru-base gas fit-
2
ting. Attach a
1
/
-in. pipe nipple with minimum length of
2
16-in. (406 mm) (field-supplied) to the street elbow and ex-
X
GAS
*
REGULATOR
*
DRIP LEG
*
PER NFGC
FIELD-FABRICATED
SUPPORT
*
*Field supplied.
NOTE: Follow all local codes.
SPACING OF SUPPORTS
X DIMENSION (FT.)
6
8
10
1
/
-in.
2
3
/
-in. electrical bulk-
4
LOW VOLTAGE
CONDUIT
CONNECTOR
HIGH VOLTAGE
CONDUIT
CONNECTOR
tend it through the access panel at the gas support bracket.
See Fig. 17.
BRASS FITTING
EMBOSSMENT
FOR 3-6 TON UNITS
Fig. 17 — Gas Line Piping for 3 to 5 Ton Units Only
Other hardware required to complete the installation of
the gas supply line includes a manual shutoff valve, a sedi-
ment trap (drip leg) and a ground-joint union. A pressure
regulator valve may also be required (to convert gas pres-
sure from pounds to inches of pressure). The manual shutoff
valve must be located within 6 ft (1.83 m) of the unit. The
union, located in the final leg entering the unit, must be lo-
cated at least 9 in. (230 mm) away from the access panel to
permit the panel to be removed for service. If a regulator
valve is installed, it must be located a minimum of 4 ft
(1220 mm) away from the unit's flue outlet. Some munici-
pal codes require that the manual shutoff valve be located
upstream of the sediment trap. See Fig. 18 and 19 for typical
piping arrangements for gas piping that has been routed
through the sidewall of the curb. See Fig. 20 for typical pip-
ing arrangement when thru-base is used. Ensure that all pip-
ing does not block access to the unit's main control box or
limit the required working space in front of the control box.
Thru-Curb Adapter
Shut Off
Valve
Fig. 18 — Gas Piping, Typical Curb Sidewall Piping
13
SUPPORT
BRACKET
9" (229mm) min
Union
Unit Base Rail
Drip
Leg
(Example 1)
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