PB Heat MI/MIH series - Manual (Page 28)

26
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
(PB Heat, LLC suggests reading meter for 2 Cu. Ft.):
U.S. Customary Units
Input (BTU/Hr.)= 3600 x F x H
T
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
T x 3.6
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.
Burner inputs in Btu/hr for various meter timings and heat
values. (Table based on 2 cubic feet of gas through meter).
Burner inputs in kW for for various meter timings and
heat values. (Table based on 0.0566 cubic meter of gas
through meter).
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.
START-UP PROCEDURES
288000
240000
205714
180000
160000
144000
130909
120000
110769
102857
96000
90000
84706
80000
75789
72000
68571
65455
62609
60000
57600
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
125
295200
246000
210857
184500
164000
147600
134182
123000
113538
105429
98400
92250
86824
82000
77684
73800
70286
67091
64174
61500
59040
302400
252000
216000
189000
168000
151200
137455
126000
116308
108000
100800
94500
88941
84000
79579
75600
72000
68727
65739
63000
60480
Heat Value of Gas
(Btu/cubic foot)
1000 1025 1050
Time that
meter is
read (sec)
Table 7.1a: Meter Conversion – Natural Gas
(U.S. Customary Units)
Time that
meter is
read (sec)
Heat Value of Gas
(MJ/cubic meter)
37.26 38.19 39.12
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
125
84.36
70.30
60.25
52.72
46.86
42.18
38.34
35.15
32.44
30.13
28.12
26.36
24.81
23.43
22.20
21.09
20.08
19.17
18.34
17.57
16.87
86.46
72.05
61.76
54.04
48.03
43.23
39.30
36.03
33.25
30.88
28.82
27.02
25.43
24.02
22.75
21.62
20.59
19.65
18.80
18.01
17.29
88.57
73.81
63.26
55.35
49.20
44.28
40.26
36.90
34.06
31.63
29.52
27.68
26.05
24.60
23.31
22.14
21.09
20.13
19.25
18.45
17.71
Table 7.1b: Meter Conversion – Natural Gas
(SI Metric Units)