-- 6 --
462 06 1211 00
3/17/06
FIRE AND/OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Do NOT attempt to light the burner with a match or
flame of any kind.
!
HEATING INPUT RATE CHECK
The gas input to the unit is determined by measuring
the gas flow at the meter. Measuring gas flow at the
meter is recommended for natural gas units.
To
measure the heating input, perform the following
steps:
1. Turn off all other gas appliances that use the same
meter.
2. Turn off gas supply to unit and attach manifold
pressure gauge as instructed in the ”Gas Valve
Adjustment” section.
3. With gas
ON
to the unit and the unit operating, record
the number of seconds for the gas meter dial to make
one revolution.
4. Divide number of seconds in Step 3 into 3600
(number of seconds in 1 hour).
5. Multiply result of Step 4 by the number of cubic feet
shown for one revolution of the meter dial to obtain the
cubic feet of gas flow per hour.
6. Multiply result of Step 5 by Btu heating value of gas to
obtain total measured input in Btu/hr. Compare this
input rate with the Required Input Rate for the
installation altitude, as shown in
Table 3
. Consult with
local gas supplier if the heating value of gas is not
known.
Example: Assume that the size of the meter dial is 1 cu. ft.,
one revolution takes 44 seconds, and the heating value of
the gas is 1020 Btu/ft3. Proceed as follows:
1. 38 sec. To complete 1 revolution
2. 3600/38 = 94.7
3. 94.7 x 1 = 94.7
4. 94.7 x 1020 = 96,632 Btu/hr
For this example, the nameplate input is 100,000 Btu/hr, so
only a minor change in manifold pressure is required. In no
case should the final manifold pressure vary more than
+-- .3 ”water column from the values in
Table 2
. Never
exceed the required input rate (
Table 3
).
Table 3
0-2000
2001-3000
3001-4000
4001-5000
5001-6000
6001-7000
7001-8000
8001-9000 9001-10000
"040" or "B"
40,000
35200
33600
32000
30400
28800
27200
25600
24000
"060" or "C"
60,000
52800
50400
48000
45600
43200
40800
38400
36000
"080" or "D"
80,000
70400
67200
64000
60800
57600
54400
51200
48000
"100" or "E"
100,000
88000
84000
80000
76000
72000
68000
64000
60000
"120" or "F"
120,000
105600
100800
96000
91200
86400
81600
76800
72000
"140" or "G"
140,000
123200
117600
112000
106400
100800
95200
89600
84000
1
Note:
For PGF3, PGX3, and PDX3 models, heating model size is indicated by the numbers in the 5
th
, 6
th
, and 7
th
characters in the model number.
For PGF, PGC, PGS models, heating model size is indicated by the numbers in the 8
th
, 9
th
, and 10
th
characters in the model number.
For GPFM, GPCM, and GPSM models, heating model size is indicated by the numbers in the 8
th
, 9
th
, and 10
th
characters in the model number.
For PGAA, PGAD, PGCA, and PGCD models, heating model size is indicated by the letter in the 7
th
character in the model number.
For PGMD and PGME models, heating model size is indicated by the letter in the 7
th
character in the model number.
Required Input Rate of Furnace Converted to Natural Gas (Btu/hr)
Elevation Above Sea Level (feet)
Required Input Rate for All Models
Heating Model
Size
1
