18
FACTORY OPTION THRU-BASE CONNECTIONS (GAS
CONNECTIONS)
This service connection kit consists of a NPT gas adapter fit-
ting, an electrical bulkhead connector and a
3
/
4
-in. electrical
bulkhead connector, all factory-installed in the embossed
(raised) section of the unit basepan in the condenser section.
See Fig. 19.
Fig. 19 — Thru-Base 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.
Gas Line
Install a
1
/
2
-in. (08 and 09 size Low Gas units only) or
3
/
4
-in.
(for all other units) NPT street elbow on the thru-base gas fit-
ting. Attach an appropriate size pipe nipple with minimum
length of 16-in. (406 mm) (field-supplied) to the street elbow
and extend it through the access panel at the gas support brack-
et. See Fig. 20.
Fig. 20 — Gas Line Piping
Other hardware required to complete the installation of the gas
supply line will include a manual shutoff valve, a sediment trap
(drip leg) and a ground-joint union. A pressure regulator valve
may also be required (to convert gas pressure 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 located 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 municipal codes require that the manual shutoff valve be
located upstream of the sediment trap. See Fig. 21 and Fig. 22
for typical piping arrangements for gas piping that has been
routed through the sidewall of the curb. See Fig. 23 for typical
piping arrangement when thru-base is used. Ensure that all
piping does not block access to the unit’s main control box or
limit the required working space in front of the control box.
Fig. 21 — Gas Piping with Thru-Curb Accessory
Fig. 22 — Gas Piping with Thru-Curb Accessory
(Alternate Layout)
Fig. 23 — Gas Piping with Thru-Base Accessory
LOW VOLTAGE
CONDUIT
CONNECTOR
HIGH VOLTAGE
CONDUIT
CONNECTOR
BRASS FITTING FOR 3 TO 6 TON UNITS.
EMBOSSMENT
BRASS FITTING
FOR 3-6 TON UNITS
SUPPORT
BRACKET
9” (229mm) min
Union
Shut Off
Valve
Drip
Leg
Thru-Curb Adapter
Unit Base Rail
SHUT OFF
VALVE
UNION
9” (229mm) MIN
UNIT BASE RAIL
BURNER
ACCESS
PANEL
THRU-CURB ADAPTER
DRIP
LEG
To Next Page
Loading...
