S-CB Px 120 Manual
88
14.3.
Gas conversion butane/propane (B/P)
To use another type of gas with the boiler, only a conversion kit for butane/propane is needed, which consists of
an air restrictor and an o-ring to air tighten the gap between the fan and the venturi. This changing of gas type
involves a different calorific value and composition of the gas. Change the settings of the gas valve.
For example propane. Take the following actions:
1.
Mount the air restrictor kit as described below on this page
Set the gas valve:
2.
Turn the adjusting screw [2] three full strokes round (clockwise).
3.
Press the [SERVICE] button for about 3 seconds to start up the boiler in service mode.
4.
When, after several starting attempts, the burner does not ignite and start to burn, turn the adjusting screw
[2] one quarter stroke back (counterclockwise) and start service mode again.
5.
When the burner ignites and starts to burn, continue the setting of the gas valve at maximum and minimum
load, as described in the previous chapters and use the values for Natural Gas G31.
Gas type
Nat. Gas G20
1
Nat. Gas G25
1
Prop. G31
1, 2
Buta. (B/P)G30
1, 2
Cal. Value Hi (EN437)
(MJ/m
3
)
34,02
29,25
88,00
116,09
CO
2
max. output
(%)
3
9,0
9,0
10,3
10,4
O
2
max. output
(%)
3
4,9
4,9
5,2
5,3
CO
2
min. output
(%)
3
8,5
8,5
9,6
9,6
O
2
min. output
(%)
3
5,7
5,7
6,2
6,5
1
measured without boiler door.
2
A butane/propane (B/P) kit is needed,
see accessories list, page 13.
Butane or propane or B/P mixtures may only be used with an air restrictor, and with the venturi directly
mounted on the fan. See the instructions for butane/propane kit below.
3
Set the gas valve until measured CO
2
values match table within ± 0,1% (O
2
values within ± 0,2%).
Instructions for butane/propane kit application
The air restrictor is a plastic cap with a slit in it. To apply it, follow the next steps (see picture below):
•
Disassemble the complete burner door unit, as described in section 17.2. on page 100.
•
Loosen the three screws (1) that connect the venturi to the fan.
•
Remove the plastic ‘ring’ (2) from the fan, and replace it by the O-ring (3), supplied with the butane/propane
air restrictor kit.
NOTICE: It is very important that the plastic ring (2) is discarded, to ensure that the venturi is mounted air-tight
onto the fan.
•
Put the air restrictor itself (4) completely over the venturi inlet opening and secure it with the supplied clamp
(5).
NOTICE: Make sure that the air restrictor is placed correctly: it should have the slit horizontal when the other
components have the orientation as in the picture.
•
Reassemble both the burner door unit on the heat exchanger and the venturi with air restrictor on the fan.
Picture: application of the air restrictor kit for butane/propane
1. venturi screws
2. plastic ring
3. O-ring
4. air restrictor
5. clamp
Summary of Contents for S-CB Px 120
Page 2: ...S CB Px 120 Manual 2 ...
Page 6: ...S CB Px 120 Manual 6 ...
Page 33: ...S CB Px 120 Manual 33 9 4 Electrical schematics ...
Page 34: ...S CB Px 120 Manual 34 ...
Page 111: ...S CB Px 120 Manual 111 ...
Page 115: ...S CB Px 120 Manual 115 weather dependent control 49 73 ...
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