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

S

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A

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