-- 27 --
level of gas controls. Place a ground joint union between gas
control manifold and manual gas shutoff valve. (See Fig. 29.)
UNION
SEDIMENT
TRAP
MANUAL
SHUTOFF
VALVE
(REQUIRED)
GAS
SUPPLY
A93324
Fig. 29 -- Typical Gas Pipe Arrangement
If local codes allow the use of a flexible gas appliance connector,
always use a new listed connector. Do not use a connector which
has previously served another gas appliance.
FIRE OR EXPLOSION HAZARD
Failure to follow this safety warning exactly could result in
serious injury, death or property damage.
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. A fire or explosion
could result causing property damage, personal injury or loss
of life.
!
WARNING
An accessible manual shutoff valve MUST be installed external
to furnace casing and within 6 ft (1.8 M) of furnace. A 1/8-in. (3
mm) 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. 48.)
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. After all connections have been made, purge lines and
check for leakage at furnace prior to operating furnace.
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 furnace gas valve and
accessible manual shutoff valve before test.
The gas supply pressure shall be within the maximum and
minimum inlet supply pressures marked on the rating plate with
the furnace burners ON and OFF.
Step 8 -- Electrical Connections
See Fig. 30 for field wiring diagram showing typical field 115-v
and 24-v wiring. Check all factory and field electrical
connections for tightness.
Field-supplied wiring shall conform with the limitations of 63
°
F
(35
°
C) rise.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in serious injury
or death.
Blower access panel door switch opens 115-v power to control
center. No component operation can occur. Do not bypass or
close switch with panel removed.
!
WARNING
FURNACE MAY NOT OPERATE
Failure to follow this caution may result in furnace operation
stopping and water pipes freezing during cold weather.
Furnace control must be grounded for proper operation or
control will lock out. Control is grounded through
green/yellow wire routed to gas valve and burner box screw.
CAUTION
!
Table 6 – Electrical Data
UNIT SIZE
VOLTS-
HERTZ-
PHASE
OPERATING
VOLTAGE RANGE
MAX UNIT
AMPS
UNIT AMPACITY†
MIN
WIRE
SIZE
MAX WIRE
LENGTH
FT (M)‡
MAX FUSE OR
CKT BKR AMPS**
Max*
Min*
040---08 / 024040
115—60—1
127
104
6.1
8.4
14
44 (13.4)
15
040---12 / 036040
115—60—1
127
104
7.3
10.0
14
37 (11.2)
15
060---08 / 024060
115—60—1
127
104
6.1
8.4
14
44 (13.4)
15
060---12 / 036060
115—60—1
127
104
7.1
9.8
14
38 (11.5)
15
060---16 / 048060
115—60—1
127
104
9.5
12.8
14
29 (8.8)
15
080---12 / 036080
115—60—1
127
104
7.6
10.4
14
36 (10.9)
15
080---16 / 048080
115—60—1
127
104
10.0
13.4
14
28 (8.5)
15
080---20 / 060080
115—60—1
127
104
14.1
18.4
12
31 (9.4)
20
100---16 / 048100
115—60—1
127
104
10.2
13.5
14
27 (8.2)
15
100---20 / 060100
115—60—1
127
104
14.8
19.3
12
30 (9.1)
20
120---20 / 060120
115—60—1
127
104
14.6
19.1
12
30 (9.1)
20
140---20 / 060140
115—60—1
127
104
14.3
18.8
12
30 (9.1)
20
* Permissible limits of voltage range at which unit will operate satisfactorily.
† Unit ampacity = 125 percent of largest operating component’s full load amps plus 100 percent of all other potential operating components’ (EAC, humidifier,
etc.) full load amps.
‡ Length shown is as measured 1 way along wire path between unit and service panel for maximum 2 percent voltage drop.** Time-delay type is recommended
58MCB
