ICP PGN324 Installation instructions manual - Caution
14
CHECK HEATING CONTROL
Start and check the unit for proper heating control operation
as follows (see furnace lighting instructions located inside
burner or blower 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. After a call for heating, the main burner should light
within 5 sec. 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.
CHECK GAS INPUT
Check gas input and manifold pressure after unit start--up
(See Table 3). If adjustment is required proceed as follows:
-- The rated gas inputs shown in Table 3 are for altitudes
from sea level to 2000 ft above sea level. These inputs
are based on natural gas with a heating value of 1050
Btu/ft
3
at 0.65 specific gravity, or propane gas with a
heating value of 2500 Btu/ft
3
at 1.5 specific gravity.
-- For elevations above 2000 ft, reduce input 4% for each
1000 ft above sea level. For example at 2001 ft. a 12%
total derate is required.
-- When the gas supply being used has a different heating
value or specific gravity, refer to national and local
codes, or contact your distributor to determine the
required orifice size.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in reduced unit
and/or component life.
Do Not redrill an orifice. Improper drilling (burrs,
out--of--round holes, etc.) can cause excessive
burner noise and misdirection of burner flame. If
orifice hole appears damaged or it is suspected to
have been redrilled, check orifice hole with a
numbered drill bit of correct size.
!
CAUTION
ADJUST GAS INPUT
The gas input to the unit is determined by measuring the gas
flow at the meter or by measuring the manifold pressure.
Measuring the gas flow at the meter is recommended for
natural gas units. The manifold pressure must be measured
to determine the input of propane gas units.
Measure Gas Flow (Natural Gas Units)
Minor adjustment to the gas flow can be made by changing
the manifold pressure. The manifold pressure must be
maintained between 3.4 and 3.6 in. wc.
If larger adjustments are required, change main burner
orifices following the recommendations of national and
local codes.
NOTE: All other appliances that use the same meter must
be turned off when gas flow is measured at the meter.
Proceed as follows:
1. Turn off gas supply to unit.
2. Remove pipe plug on manifold (See Fig. 12) and
connect manometer. Turn on gas supply to unit.
3. Record number of seconds for gas meter test dial to
make one revolution.
4. Divide number of seconds in Step 3 into 3600 (number
of seconds in one hr).
5. Multiply result of Step 4 by the number of (cubic feet) cu
ft shown for one revolution of test dial to obtain cu ft of
gas flow per hour.
6. Multiply result of Step 5 by Btu heating value of gas to
obtain total measured input in Btuh. Compare this value
with heating input shown in Table 3 (Consult the local
gas supplier if the heating value of gas is not known).
EXAMPLE: Assume that the size of test dial is 1 cu ft, one
revolution takes 32 sec., and the heating value of the gas
is 1050 Btu/ft
3
. Proceed as follows:
Table 2
—
Heating Inputs
HEATING INPUT
(BTUH)
NUMBER OF
GAS SUPPLY PRESSURE (IN. WC)
MANIFOLD PRESSURE (IN WC)
NUMBER OF
ORIFICES
Natural{
Propane*{
MANIFOLD PRESSURE (IN. WC)
ORIFICES
Min
Max
Min
Max
Natural{
Propane*†
40,000
2
4.0
13.0
4.0
13.0
3.5
3.5
60,000
2
4.0
13.0
4.0
13.0
3.5
3.5
90,000
3
4.0
13.0
4.0
13.0
3.5
3.4
115,000
3
4.0
13.0
4.0
13.0
3.5
3.7
130,000
3
4.0
13.0
4.0
13.0
3.5
3.5
*When a unit is converted to propane, different size orifices must be used. See separate, natural--to--propane conversion kit
instructions.
{
Based on altitudes from sea level to 2000 ft above sea level. For altitudes above 2000 ft, reduce input rating 4 percent for each
additional 1000 ft above sea level. In Canada, from 2000 ft above sea level to 4500 ft above sea level, derate the unit 10 percent.