15
Manifold pressure for liquid propane (LP) fuel use must be ad-
justed to specified range. Follow instructions in the accessory
kit to make initial readjustment.
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. 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. 19.
Fig. 19 — Gas Piping Guide
FACTORY OPTION THRU-BASE CONNECTIONS (GAS
CONNECTION)
This service connection kit consists of a
3
/
4
-in. NPT gas adapt-
er fitting (stainless steel), a
1
/
2
-in. electrical bulkhead connec-
tor and a 1
1
/
2
-in. electrical bulkhead connector, connected to an
“L” bracket covering the embossed (raised) section of the unit
basepan in the condenser section. See Fig. 20.
Fig. 20 — Thru-the-Base Option, Shipping Position
1. Remove the “L” bracket assembly from the unit (see
Fig. 20).
2. Cut and discard the wire tie on the gas fitting. Hand
tighten the fitting if it has loosened in transit.
3. Remove connector plate assembly from the “L” bracket
and discard the “L” bracket, but retain the washer head
screws and the gasket (located between the “L” bracket
and the connector plate assembly.)
NOTE: Take care not to damage the gasket, as it is reused in the
following step.
4. Place the gasket over the embossed area in the basepan,
aligning the holes in the gasket to the holes in the basepan.
See Fig. 21.
5. Install the connector plate assembly to the basepan using 8
of the washer head screws.
NOTE: If gas and/or electrical connections are not going to occur
at this time, tape or otherwise cover the fittings so that moisture
does not get into the building or conduit in the interim.
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
3
/
4
-in. NPT street elbow on the thru-base gas fitting.
Attach a
3
/
4
-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. 22.)
Table 6 — Liquid Propane Manifold Pressure Ranges
UNIT
HIGH FIRE
LOW FIRE
48HC**14
10.0 in. wg (2490 Pa)
5.7 in. wg (1420 Pa)
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.
STEEL PIPE NOMINAL
DIAMETER (in.)
SPACING OF SUPPORTS X
DIMENSION (ft)
1
/
2
6
3
/
4
or 1
8
1
1
/
4
or larger
10
LEGEND
NFGC —
National Fuel Gas Code
* Field supplied.
NOTE: Follow all local codes.
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
1
1
/
2
” ELECTRICAL
BULKHEAD
CONNECTOR
1
/
2
” ELECTRICAL
BULKHEAD
CONNECTOR
3
/
4
” NPT GAS
ADAPTER
FITTING
Summary of Contents for WeatherMaster 48HC14
Page 5: ...5 Fig 2 Unit Dimensional Drawing 14 Size Unit ...
Page 6: ...6 Fig 2 Unit Dimensional Drawing 14 Size Unit cont ...
Page 9: ...9 Fig 4 Roof Curb Details ...
Page 25: ...25 Fig 48 48HC 14 Controls Wiring Diagram 208 230 v 460 v 575 v ...
Page 26: ...26 Fig 49 48HC 14 Power Wiring Diagram 208 230 v 460 v ...
Page 27: ...27 Fig 50 48HC 14 Power Wiring Diagram 575 v ...
Page 29: ...29 Fig 53 Typical Humidi MiZer Adaptive Dehumidification System Humidistat Wiring ...
Page 44: ...44 Fig 62 48HC14 ComfortLink Control Wiring Diagram ...
Page 45: ...45 Fig 63 48HC14 ComfortLink Power Wiring Diagram ...
Page 46: ...46 Fig 64 48HC14 ComfortLink with Humidi MiZer Power Wiring Diagram ...