Electrical Connections; 115-V Wiring - Carrier 58MVP Installation, Start-Up, And Operating Instructions Manual

Table 4—Maximum Capacity of Pipe*
NOMINAL
IRON INTERNAL
PIPE DIAMETER
SIZE (IN.)
(IN.)
1/2 0.622
3/4 0.824
1 1.049
1-1/4 1.380 1400
1-1/2 1.610 2100
* Cubic ft of gas per hr for gas pressures 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 9-2 NFPA 54-2002.
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. 20.)
An accessible manual shutoff valve MUST be installed external to
furnace casing and within 6 ft of furnace. A 1/8-in. NPT plugged
tapping, accessible for test gauge 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 gauge connection providing test pressure DOES NOT
exceed maximum 0.5 psig (14-in. wc) stated on gas valve. (See
Fig. 47.)
Piping should be pressure and leak tested in accordance with
NFGC in the United States or NSCNGPIC in Canada, local, and
national plumbing and gas codes before the furnace has been
connected. If pressure exceeds 0.5 psig (14-in. wc), gas supply
pipe must be disconnected from furnace and capped before
pressure test.
If test pressure is equal to or less than 0.5 psig (14-in. wc), turn off
electric shutoff switch located on gas valve before test. It is
recommended that ground joint union be loosened before pressure
testing. After all connections have been made, purge lines and
check for leakage at furnace prior to placing it into service.
The gas supply pressure shall be within the maximum and
minimum inlet supply pressures marked on the rating plate with
the furnace burners ON at HI-HEAT and OFF.
Step 6—Electrical Connections
See Fig. 21 for field wiring diagram showing typical field 115-v
and 24-v wiring. Check all factory and field electrical connections
for tightness.
GAS
SUPPLY
MANUAL
SHUTOFF
VALVE
(REQUIRED)
SEDIMENT
TRAP
UNION
Fig. 20—Typical Gas Pipe Arrangement
LENGTH OF PIPE (FT)
10 20 30 40
175 120 97 82
360 250 200 170
680 465 375 320
950 770 660
1460 1180 990
A93324
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
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Blower access door switch opens 115-v power to furnace
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control. No component operation can occur. Do not bypass or
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close switch with panel removed.
285
580
900
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation.
Furnace control must be grounded for proper operation or
control will lock out. Control is grounded through
green/yellow wire connected to gas valve and burner box
screw.

115-V WIRING

Before proceeding with electrical connections, make certain that
voltage, frequency, and phase correspond to that specified on
furnace rating plate. Also, check to be sure that service provided
by power supply is sufficient to handle load imposed by this
equipment. Refer to rating plate or Table 5 for equipment electrical
specifications.
Make all electrical connections in accordance with National
Electrical Code (NEC) ANSI/NFPA 70-2002 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.
Field-supplied wiring shall conform with the limitations of 63°F
(33°C) rise.
Use a separate branch electrical circuit containing a properly sized
fuse or circuit breaker for this furnace. See Table 5 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, furnace control status code indicator light will
flash rapidly and furnace will NOT operate.
FIRE HAZARD
Failure to follow this warning could result in intermittent
operation.
Do not connect aluminum wire between disconnect switch
and furnace. Use only copper wire. (See Fig. 22.)
ELECTRICAL SHOCK AND FIRE HAZARD
Failure to follow this warning coud result in electrical shock,
fire, or death.
The cabinet MUST have an uninterrupted or unbroken ground
according to NEC ANSI/NFPA 70-2002 and Canadian Elec-
trical Code CSA C22.1 or local codes to minimize personal
injury if an electrical fault should occur. This may consist of
electrical wire or conduit approved for electrical ground when
installed in accordance with existing electrical codes. Do not
use gas piping as an electrical ground.
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