Bryant 312AAV User Manual

Page 12

WARNING: Use proper length of pipe to avoid stress on

gas control manifold. Failure to follow this warning could

result in a gas leak resulting in fire, explosion, personal

injury, or death.

Install a sediment trap in riser leading to furnace. Trap can be
installed by connecting a tee to riser leading to furnace so
straight-through section of tee is vertical. Then connect a capped
nipple into lower end of tee. Capped nipple should extend below
level of gas controls. Place a ground joint union between gas
control manifold and manual gas shutoff valve. (See Fig. 18.)

Piping should be pressure tested in accordance with local and

national plumbing and gas codes before the furnace has been

attached. If the pressure exceeds 0.5 psig (14-in. wc), the gas

supply pipe must be disconnected from the furnace and capped

before the pressure test. If the test pressure is equal to or less than

0.5 psig (14-in. wc), turn off electric shutoff switch located on the

gas valve before the test. It is recommended that the ground joint

union be loosened before pressure testing.
After all connections have been made, purge the lines and check

for gas leakage with regulated gas supply pressure.
An accessible manual shutoff valve MUST be installed upstream

of furnace gas controls and within 6 ft of furnace. A 1/8-in. NPT

plugged tapping, accessible for test gage connection, MUST be

installed immediately upstream of gas supply connection to

furnace and downstream of manual shutoff valve.
NOTE: The gas valve inlet pressure tap connection is suitable to

use as test gage connection providing test pressure DOES NOT

exceed maximum 0.5 psig (14-in. wc) stated on gas valve. (See

Fig. 33.) Piping should be pressure tested in accordance with

NFGC, local and national plumbing and gas codes before furnace

is attached. In Canada, refer to current edition of NSCNGPIC.

VIII. ELECTRICAL CONNECTIONS

See Fig. 21 for field wiring diagram showing typical field 115-v

wiring.Check all factory and field electrical connections for

tightness.

WARNING: Blower access panel door switch opens

115-v power to control. No component operation can

occur. Do not bypass or close switch with panel removed.

Failure to follow this warning could result in personal

injury or death.

CAUTION: Furnace control must be grounded for

proper operation or control will lock out. Control is

grounded through green wire routed to gas valve and

burner box screw.

A. 115–v Wiring
Before proceeding with electrical connections, make certain that
voltage, frequency, and phase correspond to that specified on unit
rating plate. Also, check to be sure that service provided by utility
is sufficient to handle load imposed by this equipment. Refer to
rating plate or Table 6 for equipment electrical specifications.

Make all electrical connections in accordance with National
Electrical Code (NEC) ANSI/NFPA 70-1999 and any local codes
or ordinances that might apply. For Canadian installations, all
electrical connections must be made in accordance with Canadian
Electrical Code CSA C22.1 or authorities having jurisdiction.

CAUTION: Do not connect aluminum wire between

disconnect switch and furnace. Use only copper wire.

CAUTION:

Use a separate, fused branch electrical circuit containing a properly
sized fuse or circuit breaker for this furnace. See Table 6 for wire
size and fuse specifications. A disconnecting means must be
located within sight from and readily accessible to furnace.
NOTE: Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, control LED status indicator light will flash
rapidly and furnace will NOT operate.

TABLE 4–FILTER INFORMATION (IN.)

FURNACE

CASING WIDTH

FILTER SIZE

FILTER

TYPE

Side Return

Bottom Return

17–1/2

(1) 16 x 25 x 1† (1) 16 x 25 x 1† Cleanable

† Factory provided with the furnace.

TABLE 5–MAXIMUM CAPACITY OF PIPE*

NOMINAL

IRON

PIPE

SIZE

(IN.)

INTERNAL

DIAMETER

(IN.)

LENGTH OF PIPE (FT)

1/2

0.622

175

120

3/4

0.824

360

250

200

170

151

1.049

680

465

375

320

285

1–1/4

1.380

1400

950

770

660

580

1–1/2

1.610

2100

1460

1180

990

900

* Cubic tf if gas per hr for gas pressure of 0.5 psig (14–in wc) or less, and a

pressure drop of 0.5–in wc (based on a 0.60 specific gravity gas).

Ref: Table 10–2 NFGC.

Fig.16–Horizontal Installation on Blocks

A00344

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