Advertisement
Table
4 --
Rated
Gas Inputs
at Indicated
Manifold
Pressures
UNIT PY1 P
018040, 024040, 030040
024060, 030060, 036060, 042060
030080, 036080, 042080,
048080, 060080
036100, 042100, 048100, 060100
036120, 042120, 048120, 060120
048140, 060140
NUMBER
OF
ORIFICES
1
2
2
2
3
3
GAS SUPPLY PRESSURE
(in. wg)
Natural
Propane
Min
Max
Min
Max
4.0
13.0
4.0
!3.0
4.0
13.0
4.0
!3.0
4.0
13.0
4.0
!3.0
4.0
13.0
4.0
!3.0
4.0
13.0
4.0
13.0
4.0
13.0
4.0
!3.0
MANIFOLD
NATURAL GAS
PROPANE*
PRESSURE
(in, wg)
Natural
Propane
3.5
3.1
3.5
3.3
3.5
3.4
3.5
3.7
3.5
3.5
3.5
3.4
Orifice
Heating
Drill
Input
Size
(Btuh)t
32
40,000
32
58,000
32
80,000
32
95,000
32
120,000
32
138,000
Orifice
Drill
Size
41
47
42
4O
42
4O
Heating
Input
(Btuh)t
40,000
54,000
80,000
95,000
115,000
!33,000
*When a unit is converted to propane, different size orifices must be used. See separate natural-to-propane
conversion kit
instructions.
1-Based on altitudes from sea level to 2000 ft above sea level. For altitudes above 2000 ft, reduce input rating 4% 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%.
MANIFOLD
PIPE
PLUG
Fig. 19-
Burner
Assembly
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
tire level
specified
in Table
4.
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.
19), 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
4. 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
fl'om 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
tire 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
tire same
for each
burner.
Propane
will have
blue
flame
with
yellow
tips.
See
Fig.
20. 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
5 shows
the
approved
temperature
rise
range
for each
heating
input,
and
the
air
delivery
cfln
at various
tempera
ture
rises.
The heating
operation
airflow
must
produce
a tem-
perature
rise
that
falls
within
the
approved
range.
Refer" to Evaporator
Airflow
and
Airflow
Adjustments
section
on page
24 to adjust
heating
airflow
when
required.
--18--
Advertisement
