Warning, Step 9 — install duct connections, 48e s -- a – Carrier 48ES---A User Manual
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Table 2 – Maximum Gas Flow Capacity*
NOMINAL
IRON PIPE
SIZE (IN.)
INTERNAL
DIAMETER
(IN.)
LENGTH OF PIPE FT (m)†
10
(3)
20
(6)
30
(9)
40
(12)
50
(15)
60
(18)
70
(21)
80
(24)
90
(27)
100
(30)
125
(38)
150
(46)
175
(53)
200
(61)
1/2
.622
175
120
97
82
73
66
61
57
53
50
44
40
—
—
3/4
.824
360
250
200
170
151
138
125
118
110
103
93
84
77
72
1
1.049
680
465
375
320
285
260
240
220
205
195
175
160
145
135
1---1/4
1.380
1400
950
770
600
580
530
490
460
430
400
360
325
300
280
1---1/2
1.610
2100
1460
1180
990
900
810
750
690
650
620
550
500
460
430
*Capacity of pipe in cu ft of gas per hr for gas pressure of 0.5 psig or less. Pressure drop of 0.5---IN. W.C. (based on a 0.60 specific gravity gas). Refer to Table 2
and National Fuel Gas Code NFPA 54/ANSI Z223.1.
{
This length includes an ordinary number of fittings.
OUT
TEE
NIPPLE
CAP
IN
C99020
Fig. 8 -- Sediment Trap
NOTE: Pressure test the gas supply system after the gas supply
piping is connected to the gas valve. The supply piping must be
disconnected from the gas valve during the testing of the piping
systems when test pressure is in excess of 0.5 psig. Pressure test the
gas supply piping system at pressures equal to or less than 0.5 psig.
The unit heating section must be isolated from the gas piping
system by closing the external main manual shutoff valve and
slightly opening the ground--joint union.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
--Connect gas pipe to unit using a backup wrench to avoid
damaging gas controls.
--Never purge a gas line into a combustion chamber. Never
test for gas leaks with an open flame. Use a commercially
available soap solution made specifically for the detection of
leaks to check all connections.
--Use proper length of pipe to avoid stress on gas control
manifold.
--If a flexible connector is required or allowed by authority
having jurisdiction, black iron pipe shall be installed at
furnace gas valve and extend a minimum of 2 in. (51 mm)
outside furnace casing.
--If codes allow a flexible connector, always use a new
connector. do not use a connector which has previously
serviced another gas appliance.
!
WARNING
8. Check for gas leaks at the field--installed and
factory--installed gas lines after all piping connections have
been completed. Use a commercially available soap solution
(or method specified by local codes and/or regulations).
Step 9 — Install Duct Connections
The unit has duct flanges on the supply-- and return--air openings
on the side and bottom of the unit. For downshot applications, the
ductwork connects to the roof curb (See Fig. 3 and 4 for
connection sizes and locations).
Configuring Units for Downflow (Vertical) Discharge
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing or servicing system, always turn off main
power to system and install lockout tag. There may be
more than one disconnect switch.
!
WARNING
1. Open all electrical disconnects before starting any service
work.
2. Remove horizontal (metal) duct covers to access vertical
(downflow) discharge duct knockouts in unit basepan.
3. Using Fig. 10 as a guide, proceed to cut out the downflow
duct panels.
4. Drill 1/2 in. (13 mm) diameter or larger holes in all four
corners of duct panels.
NOTE: On large chassis units remove sheet metal shields on
panels by using a screw driver to shear off retainers and discard.
5. On left and side supply duct opening side with keyhole or
single bladed hacksaw cut out panel along “V” groove.
6. On right side, with keyhole or single blade hacksaw, with
teeth facing up and starting from the front and moving to
the rear, cut along “V” groove.
7. Now with three sides cut, flex panel up and down to re-
move.
8. Replace side access panel and duct cover.
9. After completing unit conversion, perform all safety checks
and power up unit.
Alternate Method
1. Open all electrical disconnects and install lockout tag before
starting any service work.
2. Remove horizontal (metal) ductcovers to access vertical
(downflow) discharge duct knockouts in unit basepan. (See
Fig. 9.)
3. Leave top shipping crate on unit during this method.
4. Tip unit over on the front side (access panels) so the bottom
of the base pan is accessible.
5. Drill two holes diagonally opposed, of suitable size to ac-
commodate jigsaw or reciprocating saw. (See Fig. 10.)
48E
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