915SB: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
23
PRESSURE TESTING BELOW
½
psig:
The furnace must be isolated from the gas supply piping by closing its
individual manual shut-off valve during any pressure testing of the gas
supply piping system at test pressures equal to or less than
½
psig (3.5
kPa).
An accessible manual equipment shutoff valve MUST be installed
external to furnace casing and within 6 ft. (2 M) of furnace.
Install a sediment trap externally in the riser leading to furnace as shown
in
. Connect a capped nipple into lower end of tee. Capped nipple
should extend below level of furnace gas controls. Place a ground
joint
union between furnace gas control valve and exterior manual
equipment
gas shutoff valve.
A11035
Fig. 32 – Typical Gas Pipe Arrangement
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 equipment shutoff
valve.
Piping should be pressure and leak tested in accordance with the current
edition of the
NFGC in the United States, local, and
national plumbing
and gas codes before the furnace has been
connected. Refer to current
edition of NSCNGPIC in Canada. After all connections have been made,
purge lines and
check for leakage at furnace prior to operating furnace.
NOTE:
The furnace gas control 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. w.c.) stated
on gas control valve.
See
.
If pressure exceeds 0.5 psig (14-in. w.c.), gas supply pipe must be
disconnected from furnace and capped before and during supply
pipe
pressure test. If test pressure is equal to or less than 0.5 psig
(14-in. w.c.),
turn off electric shutoff switch located on furnace gas control valve and
accessible manual equipment shutoff valve before and during supply
pipe pressure test. After all connections have been made, purge lines and
check for leakage at furnace prior to operating furnace.
Gas Pipe Grommet
For direct vent (2-pipe) applications, the knockout for the gas pipe must
be sealed to prevent air leakage. Remove the knockout, install the
grommet in the knockout, then insert the gas pipe. The grommet is
included in the loose parts bag. See
.
ELECTRICAL CONNECTIONS
for field wiring diagram showing typical field 115-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.
WARNING
!
FIRE OR EXPLOSION HAZARD
A failure to follow this warning could result in personal injury, death,
and/or property damage.
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. Black iron pipe shall be
installed at the furnace gas control valve and extend a minimum of 2-in.
(51 mm) outside the furnace.
GAS
SUPPLY
MANUAL
SHUT OFF
VALVE
(REQUIRED)
SEDIMENT
TRAP
UNION
NOTE: Union may be inside the
vestibule where permitted by
local codes.
FRONT
WARNING
!
ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD
Failure to follow safety warnings could result in dangerous operation,
serious injury, death or property damage.
Improper servicing could result in dangerous operation, serious injury,
death or property damage.
-
Before servicing, disconnect all electrical power to furnace.
-
When servicing controls, label all wires prior to disconnection.
Reconnect wires correctly.
-
Verify proper operation after servicing.
-
Always reinstall access doors after completing service and
maintenance.
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury or death.
Blower door switch opens 115-v power to control. No component
operation can occur. Do not bypass or close switch with blower door
removed.
WARNING
!
ELECTRICAL SHOCK AND FIRE HAZARD
Failure to follow this warning could result in personal injury, death, or
property damage.
The cabinet MUST have an uninterrupted or unbroken ground
according to NEC NFPA 70 or local codes to minimize personal injury
if an electrical fault should occur. In Canada, refer to Canadian
Electrical Code CSA C22.1. This may consist of electrical wire,
conduit approved for electrical ground or a listed, grounded power cord
(where permitted by local code) when installed in accordance with
existing electrical codes. Refer to the power cord manufacturer’s
ratings for proper wire gauge. Do not use gas piping as an electrical
ground.
WARNING
!
FIRE HAZARD
Failure to follow this warning could result in personal injury, death, or
property damage.
Do not connect aluminum wire between disconnect switch and furnace.
Use only copper wire. See