Page 21
Leak Check
After gas piping is completed, carefully check all piping
connections (factory- and field-installed) for gas leaks. Use
a leak detecting solution or other preferred means.
NOTE - If emergency shutoff is necessary, shut off the main
manual gas valve and disconnect the main power to the
furnace. The installer should properly label these devices.
CAUTION
Some soaps used for leak detection are corrosive to
certain metals. Carefully rinse piping thoroughly af
ter leak test has been completed. Do not use
matches, candles, flame or other sources of ignition
to check for gas leaks.
The furnace must be isolated by closing its individual
manual shut‐off valve and disconnecting from from the gas
supply system the during any pressure testing of the gas
supply system at pressures greater than
1/2 psig (3.48
kPa, 14 inches w.c.).
IMPORTANT
When testing pressure of gas lines, gas valve must
be disconnected and isolated. See figure 27. Gas
valves can be damaged if subjected to pressures
greater than 1/2 psig (3.48 kPa, 14 inches w.c.).
MANUAL MAIN
SHUT-OFF VALVE
WILL NOT HOLD
NORMAL TEST
PRESSURE
CAP
ISOLATE
GAS VALVE
FURNACE
FIGURE 27
1/8 NPT PLUG
Electrical
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic discharge can affect elec
tronic components. Take precautions
to neutralize electrostatic charge by
touching your hand and tools to metal
prior to handling the control.
The unit is equipped with a field make-up box on the left
hand side of the cabinet. The make-up box may be moved
to the right side of the furnace to facilitate installation. If the
make-up box is moved to the right side, clip the wire ties
that bundle the wires together. The excess wire must be
pulled into the blower compartment. Secure the excess
wire to the existing harness to protect it from damage.
INTERIOR MAKE-UP BOX INSTALLATION
FIGURE 28
BOX
Right Side
Refer to figure 29 for schematic wiring diagram and trou
bleshooting.
The power supply wiring must meet Class I restrictions.
Protected by either a fuse or circuit breaker, select circuit
protection and wire size according to unit nameplate.
NOTE -
Unit nameplate states maximum current draw.
Maximum over-current protection allowed is 15 AMP.
Holes are on both sides of the furnace cabinet to facilitate
wiring.
Install a separate (properly sized) disconnect switch near
the furnace so that power can be turned off for servicing.
Before connecting the thermostat, check to make sure the
wires will be long enough for servicing at a later date. Make
sure that thermostat wire is long enough to facilitate future
removal of blower for service.
Complete the wiring connections to the equipment. Use the
provided unit wiring diagram. Use 18-gauge wire or larger
that is suitable for Class II rating for thermostat connec
tions.
Electrically ground the unit according to local codes or, in
the absence of local codes, according to the current Na
tional Electric Code (ANSI/NFPA No. 70). A green ground
wire is provided in the field make-up box.
NOTE - The 80AF1UH furnace contains electronic compo
nents that are polarity sensitive. Make sure that the furnace
is wired correctly and is properly grounded.