440 01 1024 01
Specifications are subject to change without notice
37
Changing Orifices for High Altitude
ELECTRICAL SHOCK, FIRE OR EXPLOSION
HAZARD.
Failure to follow this warning could result in
personal injury, death and/or property damage.
Turn OFF electric power (at disconnect) and gas
supply (at manual valve in gas line) when installing
orifices. Installation of orifices requires a qualified
service technician.
!
WARNING
NOTE:
Main burner orifices can be changed for high altitudes.
1. Disconnect gas line from gas valve.
2. Remove manifold from furnace.
3. Remove the orifices from the manifold and replace them
with properly sized orifices.
4. Tighten orifices so it is seated and gas tight.
(See
Figure 39
)
5. Reinstall manifold. Ensure burners do
NOT
bind on new
orifices.
Figure 39
Changing Orifices
Measure from face of orifice
to the back side of the
manifold.
1.11
″
(28.2mm)
1.21
″
(30.8mm)
Natural Gas Input Rating Check
SEE CHECKS AND ADJUSTMENTS, Natural Gas Input Rating
Check
in this manual.
Final Gas Piping Check
FIRE OR EXPLOSION HAZARD.
Failure to follow this warning could result in
personal injury, death, and/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 and/or
loss of life.
!
WARNING
1. The furnace and the equipment shut off valve must be
disconnected from the gas supply piping system during any
pressure testing of that system at test pressures in excess
of
1
/
2
″
PSIG. Close the manual shut--off valve before testing
at such pressures.
2. When installation is complete, test all pipe connections for
leaks with the gas pressure less than
1
/
2
″
PSIG to the gas
valve.
3. The furnace must be isolated from the gas supply system by
closing the equipment shut off valve during any pressure
testing of the gas supply system at test pressure equal to or
less than
1
/
2
″
PSI.
4. Apply a commercial soap solution to all joints to test for
leaks. Correct any leaks indicated by bubbles.
5. Correct even the smallest leak at once.
6. Check for leaks at gas valve and orifice connections to the
burner manifold while the furnace is operating.
RISQUE D
‘
INDENDIE OU D
‘
EXPLOSION.
Le non--respect des avertissements de sécurité
pourrait d
‘
entrainer des blessures graves, la mort
ou des dommages matériels.
Ne jamais utiliser une flamme nue por vérifier la
présence des fuites de gaz. Pour la vérification de
tous les joints, utiliser plutôt une solution
savonneuse
commerciale
fabriquée
spécifiquement pur la détection des fuites de gaz.
Un incendie ou une explosion peut entrainer des
dommages matériels, des blessures ou la mort.
!
AVERTISSEMENT
7. Electrical Wiring
ELECTRICAL SHOCK HAZARD.
Failure to follow this warning could result in
personal injury or death.
Turn OFF electrical power at fuse box or service
panel before making any electrical connections
and ensure a proper ground connection is made
before connecting line voltage.
!
WARNING
Power Supply Wiring
The furnace
MUST
be electrically wired and grounded in
accordance with local codes, or in the absence of local codes with
the latest edition of The National Electric Code, ANSI NFPA 70
and/or The Canadian Electric Code CSA C22.1.
The power supply to the furnace connections must be between
104 VAC and 127 VAC during furnace operation for acceptable
performance.
Field wiring connections must be made inside the furnace
connection box. A suitable strain relief should be used at the point
the wires exit the furnace casing.
Copper conductors shall be used.
Line voltage wires should
conform to temperature limitation of 63
°
F (35
°
C) rise and be sized
for the unit maximum amps stated on the rating plate. Add the full
load amps for potential field--installed accessories such as
electronic air cleaners and humidifiers that would receive power
from the furnace control. The furnace control is rated for a
maximum of 1.0 amps combined for EAC and HUM. Consult NEC
or local codes for proper wire and circuit sizing.
NOTE: Furnace will not have normal operation if line polarity is
reversed. Check ALL field and control connections prior to
operation.