Heat Wise SU-2A Manual page 12

____ 4. Clock the gas meter and check that the correct firing rate is achieved. If the firing rate is low, the
gas pressure should be increased slightly. If the firing rate is too high then the gas pressure should
be decreased. (Usually if the stack temperature is below 300F the firing rate is too low. If the stack
temperature is over 600F then the firing rate is usually too high or on rare occasions the heat
exchanger is blocked up)
Gas Input to Burner in ft
10
12
14
16
18
20
22
24
26
30
35
40
45
* For BTU/hr Natural gas multiply by 1000
For BTU/hr LPG multiply by 2500
____ 5. If the firing manifold has been readjusted, redo steps 2 and 4
____ 6.Check that the draft over-fire is positive
Use a combustion analyzer and record the readings below.
BURNER OPERATION: Record the Readings at Steady State
Draft over fire at steady state (should be Positive – refer to boiler manual)
Natural Gas CO % = (9.0% to 9.8%) or O
2
LPG CO % = (10.5% to 11.5%) or O
2
Gross Stack Temperature (350
NOx (If required)
Carbon Monoxide (CO) in PPM (less than 100 PPM ideal; should not
exceed 400 PPM Oxygen free)
Incoming Gas/LPG pressure = "W.C. (minimum 5", maximum 11")
Manifold Pressure = "W.C.
Head Setting
Air Setting
3
/hr *
3 3 3
1/2 ft 1 ft 2 ft
180 360 720
150 300 600
129 257 514
113 225 450
100 200 400
180 360
164 327
150 300
138 277
120 240
103 206
180
160
% = (5.0% to 3.5%)
2
% = (5.0% to 3.5%)
2
o o
F minimum, 450 F maximum)
3 3 3
5 ft 2 ft 5 ft
1800 50 144 360
1500 55 131 327
1286 60 120 300
1125 65 111 277
1000 70 103 257
900 75 240
818 80 225
750 90 200
692 100 180
600 110 164
514 120 150
450 130 138
400
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