Install Instructions

24
B. CONTROL DESCRIPTIONS
See Figure 6.1 in Section 6 (Electrical) for locations of
these devices.
1. FLAME ROLL-OUT SAFETY SHUT-OFF SWITCH
(FLAME ROLL-OUT SWITCH) – A thermally
activated switch located between the first burner
from the left and the manifold bracket. The flame
roll-out safety shut-off switch will sense excessive
temperature caused by continued flame roll-out and
shut down main burner gas. This is a non-recycling
switch that must be replaced once it has been
activated and the cause of the roll-out eliminated.
2. VENT SAFETY SHUT-OFF SWITCH (SPILL
SWITCH) – A thermally activated, manually
resetable switch located in the draft hood relief
opening. If venting system becomes partially or
totally blocked, the vent safety shut-off switch will
sense excessive temperature caused by flue products
exiting the draft hood relief opening and shut down
main burner gas.
3. LIMIT WITH LOW WATER CUT-OFF – A Beckett
7600B or Hydrolevel 3200 control incorporate a
thermally activated adjustable switch that will shut
down main burner gas if the supply water temp
exceeds the control setting. It will also shut down
main burner gas if the water level in the boiler drops
below the control’s sensing well. The temperature
switch will automatically reset when the boiler supply
water temp drops below the control setpoint. The
low water cut-off switch will automatically reset when
the water level is above the control’s sensing well.
4. LOW WATER CUT-OFF (FOR GRAVITY SYSTEMS
OR HOT WATER BOILERS INSTALLED ABOVE
RADIATION LEVEL) – If limit control does not
incorporate a low water cut-off feature then install a
level-sensing device (float or probe) located in supply
piping near the boiler.
C. ADJUSTMENT OF GAS PRESSURE
REGULATOR
1. Using the manometer setup installed in part 7A, set
manifold pressure as follows for various gases.
a. Natural Gas . . .3.5″ Water Column (0.9 kPa)
b. LP Gas . . . . .10.0″ Water Column (2.5 kPa)
2. To adjust gas pressure, turn adjusting screw of gas
pressure regulator counterclockwise to decrease
pressure, clockwise to increase pressure. Refer to
Figure 7.2 for location of gas pressure regulator.
Replace the cap screw when adjustment is complete.
3. In no case should the final manifold pressure vary
more than ±0.3 inches water column (0.07 kPa)
from the above specified pressures. Any necessary
major changes in the flow should be made by
changing the size of the burner orifice spuds.
4. When adjustment is complete, turn off boiler, gas
flow and electricity to boiler. Remove manometer
connection from valve and plug tapping with plug
provided. Turn utilities back on and resume
checkout.
D. 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).
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)