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Drill a 3/8" hole in the PVC exhaust
vent
piping
approximately 18" above where
the
PVC exits
the side
of
the furnace
for
your combustion
analysis equipment. (Seal with
RTV
silicone
when finished conducting combustion analysis).
BURNER ADJUSTMENT
1) Operate burner
for
15 minutes before
conducting test work.
2) Adjust burner settings until a trace
(0-1
on
a smoke scale
of
10) is obtained with smoke
test pump.
3)
Read C02%. This should
be
approximately 13.0%.
4) Increase air
to
burner
to
reduce
C02%
1.0
to
1.5% less than where you were able
to
obtain a trace
of
smoke.
This procedure allows a margin
of
reserve for
variable conditions.
5) Re-check smoke
to
insure it is
O.
Your
final C02%
should
be
approximately 11.5%
Check vent
stack
temperatures
as
below:
M
0
D
E
L
APPROX.
AMBIENT
PLUS
STACK
TEMP F.
INPUT
RATE
THERMAL
EFFICIENCY
50
20-24
58,000
97-99%
75
27-31
82,000
95-97%
100
29-33
100,000
94-96%
125
38-42
115,000
92-94%
Temperature Rise
Temperature rise
must
be
within the range
below. An incorrect temperature rise may
result in condensing in
or
overheating
of
the
heat exchanger.
Determine
and
adjUst temperature rise as
follows:
Model Temp. F.
Degree Rise
50-2.5 50-60
75-2.5
55-65
100-2.5
60-70
50-5
30-40
75-5
35-45
100-5 45-55
125-5
50-60
1.
Operate furnace with burner firing
for
approXimately ten minutes. Ensure all
registers are open and all duct dampers are
in their final (fully
or
partially open) position.
2.
Place thermometers in the return and supply
ducts as close
to
the furnace
as
possible.
Thermometers must not
be
influenced by
radiant heat by being able to "see" the heat
exchanger
HEAT
EXCHANGER
RADIATION "LINE OF
SIGHT"
~
SUPPLY
L..,/
AIR
iT'U""
Temperature Rise Measurement
3.
Subtract the return air temperature from
the supply air temperature to determine the
air temperature rise. Allow adequate time
for thermometer readings
to
stabilize.
4. Adjust temperature rise by adjusting the
circulator blower speed. Increase blower
speed to reduce temperature rise.
Decrease blower speed to increase
temperature rise.
Set thermostat heat anticipator setting
at
0.2 A
as a base point. Operate furnace and measure
anticipation amperage and adjust thermostat
to
manufacturer's instructions.
CIRCULATOR BLOWER SPEEDS
This furnace
is
equipped with a mUlti-speed
circulator blower. This blower provides ease in
adjusting blower speeds. These blower speeds
should be adjusted by the installer
to
match the
installation requirements
so
as
to
provide the
correct heating temperature rise and correct
cooling CFM.
To
adjust the circulator blower speed, proceed
as follows:
1.
Turn
OFF
power to the furnace.
2. Relocate desired motor leads to the
circulator blower terminals on the terminal
block as required.
3.
Turn ON power
to
furnace.
4.
Verify proper temperature rise
as
outlined in
Section XIV, Startup Procedure and
Adjustment - Temperature Rise.
18