Carrier 48ES---A - Manual (Page 14)

14
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death or property damage.
Do not purge gas supply into the combustion chamber. Do
not use a match or other open flame to check for gas leaks.
Use a commercially available soap solution made
specifically for the detection of leaks to check all
connections.
! WARNING
4. Verify the following conditions:
a. Make sure gas line is free of air. Before lighting the unit
for the first time, perform the following with the gas
valve in the OFF position:
NOTE: If the gas supply pipe was not purged before connecting
the unit, it will be full of air. It is recommended that the ground
joint union be loosened, and the supply line be allowed to purge
until the odor of gas is detected. Never purge gas lines into a
combustion chamber. Immediately upon detection of gas odor,
retighten the union. Allow 5 minutes to elapse, then light unit.
b. Ensure fan hub is positioned correctly with respect to
motor housing.
c. Make sure that air filter(s) is in place.
d. Make sure that condensate drain trap is filled with water
to ensure proper drainage.
e. Make sure that all tools and miscellaneous loose parts
have been removed.
START--UP
Step 1 — Check for Refrigerant Leaks
Proceed as follows to locate and repair a refrigerant leak and to
charge the unit:
1. Locate leak and make sure that refrigerant system pressure
has been relieved and reclaimed from both high-- and
low--pressure ports.
2. Repair leak following accepted practices.
NOTE: Install a filter drier whenever the system has been opened
for repair.
3. Add a small charge of Puron (R--410A) refrigerant vapor to
system and leak--test unit.
4. Recover refrigerant from refrigerant system and evacuate to
500 microns if no additional leaks are found.
5. Charge unit with Puron (R--410A) refrigerant, using an
accurate scale. Refer to unit rating plate for required charge.
Step 2 — Start--up Heating and Make Adjust-
ments
Complete the required procedures given in the Pre--Start--Up
section before starting the unit. Do not jumper any safety devices
when operating the unit. Make sure that burner orifices are
properly aligned. Unstable operation my occur when the burner
orifices in the manifold are misaligned.
Follow the lighting instructions on the heating section operation
label (located on the inside of the control access panel) to start the
heating section.
NOTE: Make sure that gas supply has been purged, and that all
gas piping has been checked for leaks.
Pipe Plug
Manifold
A07679
Fig. 12 -- Burner Assembly
MANIFOLD
BURNER
BURNER FLAME
C99021
Fig. 13 -- Monoport Burner
Check Heating Control
Start and check the unit for proper heating control operation as
follows (see furnace lighting instructions located on the inside of
the control access panel):
1. Place room thermostat SYSTEM switch in the HEAT
position and the fan switch is placed in AUTO position.
2. Set the heating temperature control of the thermostat above
room temperature.
3. The induced--draft motor will start.
4. On a call for heating, the main burner should light within 5
sec. of the spark being energized. If the burners do not light,
there is a 22--sec. delay before another 5--sec. try. If the
burners still do not light, this sequence is repeated. If the
burners do not light within 15 minutes from the initial call
for heat, there is a lockout. To reset the control, break the
24--v power to W.
5. The evaporator fan will turn on 45 sec. after the flame has
been established. The evaporator fan will turn off 45 sec.
after the thermostat has been satisfied. Please note that the
integrated gas unit controller (IGC) has the capability to
automatically reduce the evaporator “ON” delay and in-
crease the evaporator “OFF” delay in the event of high duct
static and/or partially--clogged filter.
Check Gas Input
Check gas input and manifold pressure after unit start--up (See
Table 4). If adjustment is required proceed as follows:
S The rated gas inputs shown in Table 4 are for altitudes from sea
level to 2000 ft (610 m) above sea level. These inputs are based
on natural gas with a heating value of 1025 Btu/ft
3 at 0.60
specific gravity, or propane gas with a heating value of 2500
Btu/ft
3 at 1.5 specific gravity.
48E
S
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A