Measure Manifold Pressure (Propane Units)
The main burner orifices on a propane gas unit are sized for
the unit rated input when the manifold pressure reading
matches the level specified in Table 6.
Proceed as follows to adjust gas input on a propane gas unit:
1. Turn off gas to unit.
2. Remove pipe plug on manifold (see Fig. 13), then con-
nect manometer at this point.
3. Turn on gas to unit.
4. Remove cover screw over regulator adjustment screw on
gas valve.
5. Adjust regulator adjustment screw to the correct mani-
fold pressure, as specified in Table 6. Turn adjusting
screw clockwise to increase manifold pressure, or turn
adjusting screw counterclockwise to decrease manifold
pressure.
6. Replace cover screw.
7. Turn off gas to unit. Remove manometer from pressure
tap. Replace pipe plug on gas valve, then turn on gas to
unit. Check for leaks.
D. Check Burner Flame
With burner access panel removed, observe the unit heating
operation. Watch the burner flames to see if they are light
blue and soft in appearance, and that the flames are approxi-
mately the same for each burner. Propane will have blue flame
with yellow tips. See Fig. 14. Refer to Maintenance section
for information on burner removal.
E. Airflow and Temperature Rise
The heating section for each size unit is designed and ap-
proved for heating operation within the temperature-rise range
stamped on the unit rating plate.
Table 7 shows the approved temperature-rise range for each
heating input, and the air delivery cfm at various tempera-
ture rises. The heating operation airflow must produce a tem-
perature rise that falls within the approved range.
Refer to Indoor Airflow and Airflow Adjustments section on
page 22 to adjust heating airflow when required.
Table 7 — Air Delivery (Cfm) at Indicated Temperature Rise and Rated Heating Input
HEATING
INPUT
(Btuh)
TEMPERATURE RISE °F
20 25 30 35 40 45 50 55 60 65 70
40,000 1500 1200 1000 857 750 667 600 545 500 — —
60,000 2250 1800 1500 1286 1125 1000 900 818 750 692 —
90,000 — — 2250 1929 1688 1500 1350 1227 1125 1038 964
115,000 — — — 2464 2156 1917 1725 1568 1438 1327 1232
130,000 — — — 2786 2438 2167 1950 1773 1625 1500 —
NOTE: Dashed areas do not fall within the approved temperature rise range of the unit.
Fig. 14 — Monoport Burners
—17—
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