Checking Burner Input; Check-Out Procedure - Smith GBX 70 Installation And Operation Instructoins

E. CHECKING BURNER INPUT
1. Refer to rating label mounted on the jacket top panel
to obtain the rated BTU per hour input. In no case
shall the input to the boiler exceed the value shown
on the rating label.
2. Check input by use of the following formulas
(manufacturer suggests reading meter for 2 Cu. Ft.):
U.S. Customary Units
Input (BTU/Hr.)= 3600 x F x H
Where:
3600 = Seconds per hour
F = Cubic Feet of Gas Registered on Meter
H = Heat Value of Gas in BTU/Cubic Feet
T = Time in Seconds the Meter is Read
SI Metric Units
Input (kW)= 3600 x F x H
Where:
3600 = Seconds per hour
3.6 = Megajoule (MJ) per kilowatt hour (kwhr)
F = Cubic Meters of Gas Registered on Meter
H = Heating Value of Gas in MJ/Cubic Meter
T = Time in Seconds the Meter is Read
3. As an alternative, use Table 7.1(a) and 7.1(b). Use
the heating value provided by gas supplier. Use a
stopwatch to record the time it takes for 2 cubic feet
(0.0566 cubic meter) of gas to pass through the
meter. Read across and down to determine rate.
Table 7.1a: Meter Conversion – Natural Gas
(U.S. Customary Units)
Burner inputs in Btu/hr for various meter timings and heat
values. (Table based on 2 cubic feet of gas through meter).
Time that
meter is
read (sec)
1000
25 288000
240000
30
35 205714
40 180000
45 160000
50 144000
55 130909
60 120000
65 110769
70 102857
75 96000
80 90000
85 84706
90 80000
95 75789
100 72000
105 68571
110 65455
115 62609
120 60000
125 57600
INSTALLATION AND OPERATING INSTRUCTIONS
T
T x 3.6
Heat Value of Gas
(Btu/cubic foot)
1025 1050
295200 302400
246000 252000
210857 216000
184500 189000
164000 168000
147600 151200
134182 137455
123000 126000
113538 116308
105429 108000
98400 100800
92250 94500
86824 88941
82000 84000
77684 79579
73800 75600
70286 72000
67091 68727
64174 65739
61500 63000
59040 60480
Table 7.1b: Meter Conversion – Natural Gas
(SI Metric Units)
Burner inputs in kW for for various meter timings and
heat values. (Table based on 0.0566 cubic meter of gas
through meter).
Time that
meter is
read (sec)
37.26
25 84.36
30 70.30
35 60.25
40 52.72
45 46.86
50 42.18
55 38.34
60 35.15
65 32.44
70 30.13
75 28.12
80 26.36
85 24.81
90 23.43
95 22.20
100 21.09
105 20.08
110 19.17
115 18.34
120 17.57
125 16.87
F.

CHECK-OUT PROCEDURE

1. After starting the boiler, be certain all controls are
working properly. Check to be sure that the limit will
shut off the boiler in the event of excessive water
temperature. This can be done by lowering the limit
setting until the main burners shut down. When
proper limit function is confirmed, return the dial to
its previous setting.
2. To check operation of the ignition system safety
shut-off features:
a. Standing Pilot:
i) Turn the gas control knob counterclockwise to
"PILOT". The main burner should go out
and the pilot should remain lit.
ii) Extinguish the pilot flame. Pilot gas flow
should stop within 2-1/2 minutes. Complete
shutdown is proven since the safety shut-off
valve has stopped main and pilot gas flow.
iii) Reset the boiler by following Lighting
Instructions.
iv) Observe boiler operation through one
complete cycle.
Heat Value of Gas
(MJ/cubic meter)
38.19 39.12
86.46 88.57
72.05 73.81
61.76 63.26
54.04 55.35
48.03 49.20
43.23 44.28
39.30 40.26
36.03 36.90
33.25 34.06
30.88 31.63
28.82 29.52
27.02 27.68
25.43 26.05
24.02 24.60
22.75 23.31
21.62 22.14
20.59 21.09
19.65 20.13
18.80 19.25
18.01 18.45
17.29 17.71
25