Carrier 48FC 04, Руководство по установке, Страница: 13 / 48

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The gas supply pipe enters the unit at the burner access panel
on the front side of the unit, through the long slot at the bottom
of the access panel. The gas connection to the unit is made to
the 1 /
2
-in. FPT gas inlet port on the unit gas valve.
Manifold pressure is factory-adjusted for natural gas fuel use.
Adjust as required to obtain best flame characteristics. See
Table 5.
Manifold pressure for LP fuel use must be adjusted to specified
range. Follow instructions in the accessory kit to make initial
readjustment, see Table 6.
Install a gas supply line that runs to the unit heating section.
Refer to the NFPA 54/NFGC or equivalent code for gas pipe
sizing data. Do not use a pipe size smaller than 1 /
2
-inch. Size
the gas supply line to allow for a maximum pressure drop of
0.5-in. wg (124 Pa) between gas regulator source and unit gas
valve connection when unit is operating at high-fire flow rate.
The gas supply line can approach the unit in three ways: hori-
zontally 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). Consult accessory
kit installation instructions for details on these installation
methods. Observe clearance to gas line components per
Fig. 16.
Fig. 16 — 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 /
2
-in. NPT gas adapter
fitting (brass), a 1 /
2
-in. electrical bulkhead connector and a 3 /
4
-in.
electrical bulkhead connector, all factory-installed in the em-
bossed (raised) section of the unit basepan in the condenser sec-
tion. See Fig. 17.
Fig. 17 — 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 /
2
-in. NPT street elbow on the thru-base gas fitting.
Attach a 1 /
2
-in. 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 bracket. See
Fig. 18.
Table 3 — Natural Gas Supply Line Pressure Ranges
UNIT MODEL UNIT SIZE MIN. MAX.
48FCD/E/S/R 04, 05, 06, 07
4.0 in. wg
(996 Pa)
13.0 in. wg
(3240 Pa)
48FCF/T
(High Heat Units Only)
05, 06, 07
5.0 in. wg
(1245 Pa)
13.0 in. wg
(3240 Pa)
Table 4 — Liquid Propane Supply Line Pressure
Ranges
UNIT MODEL UNIT SIZE MIN. MAX.
48FCD/E/S/R 04, 05, 06, 07
11.0 in. wg
(2740 Pa)
13.0 in. wg
(3240 Pa)
48FCF/T
(High Heat Units Only)
05, 06, 07
11.0 in. wg
(2740 Pa)
13.0 in. wg
(3240 Pa)
Table 5 — Natural Gas Manifold Pressure Ranges
UNIT MODEL UNIT SIZE HIGH FIRE LOW FIRE
48FCD/E/S/R 04, 05, 06, 07
3.5 in. wg
(872 Pa)
SEE NOTE
BELOW
48FCF/T
(High Heat Units Only)
05, 06, 07
3.5 in. wg
(872 Pa)
SEE NOTE
BELOW
NOTE: LOW FIRE, 1.7 in. wg (423 Pa), applies to the following three
phase voltage units only: 48FCE*04 and 48FCF*05/06/07.
Table 6 — Liquid Propane Manifold Pressure Ranges
UNIT MODEL UNIT SIZE HIGH FIRE LOW FIRE
48FCD/E/S/R 04, 05, 06, 07
10 in. wg
(2490 Pa)
SEE NOTE
BELOW
48FCF/T
(High Heat Units Only)
05, 06, 07
10 in. wg
(2490 Pa)
SEE NOTE
BELOW
NOTE: LOW FIRE, 5.0 in. wg (1245 Pa), applies to the following three
phase voltage units only: 48FCE*04 and 48FCF*05/06/07.
CAUTION
EQUIPMENT DAMAGE
Failure to follow this caution may result in equipment damage.
When connecting the gas line to the unit gas valve, the in-
staller MUST use a backup wrench to prevent damage to
the valve.
X
BASE UNIT
BASE RAIL
ROOF
CURB
9” MINIMUM CLEARANCE
FOR PANEL REMOVAL
MANUAL GAS
SHUTOFF VALVE
*
GAS
REGULATOR
*
48” MINIMUM
DRIP LEG
PER NFGC
*
FIELD-FABRICATED
SUPPORT
*
FROM
GAS
METER
LEGEND *Field supplied.
NOTE: Follow all local codes.
NFGC —
National Fuel Gas
Code
STEEL PIPE
NOMINAL DIAMETERS (IN.)
SPACING OF SUPPORTS
X DIMENSION (FT)
1 /
2
6
3
/
4
or 1 8
1 1 /
4
or larger 10
LOW VOLTAGE
CONDUIT
CONNECTOR
HIGH VOLTAGE
CONDUIT
CONNECTOR
BRASS FITTING FOR
3 TO 6 TON UNITS
AUXILIARY
POWER
SUPPLY
(OPTIONAL)