Strebel S-CB Px 120, Installation Operating & Maintenance Manual

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S-CB Px 120 Manual 70
11.
CONTROLLING OPTIONS AND SETTINGS
11.1. General
The following chapters describe some general functions of the boiler and their possible use.
11.1.1. E
XTRA BOILER CONTROL
When all units (cascaded) are firing at their maximum it is possible to start an extra “external” heating source. This
unit can be connected to the “Burner Burning” contacts (connection 21-22).
P5DE
Extra boiler output enable (1) (display C4)
When this parameter is set at 1 the contact “Burner Burning” will close, but only when all units are firing at a cer-
tain (programmable) input percentage. The standard factory setting for this function is “OFF”.
11.1.2. M
AX COOLING TIME
The fan will cool down the heat exchanger according to the temperature settings (parameters) of the software.
With this cooling parameter the maximum run time of the fan can be programmed.
P2LK Max cooling time (display D4)
This function is not used for central heating boilers.
11.1.3. T
EMPERATURE DISPLAY ON
/
OFF
Selection for showing the measured temperatures in the operation display of the boiler.
P5BJ Temperature display 1=on (display D5)
The measured temperature in the operation display.
0 = not visible
1 = visible
11.1.4. W
ATER PRESSURE
P4 AD pressure 0=off, 1=sensor, 2=switch (display D7).
When the water pressure exceeds 4 bar a pressure switch must be used instead of the sensor (suitable till 4 bar).
With the switch, pressure can go up to 6 bar. In this case, remove the pressure sensor and replace it by the pres-
sure switch.
Now set the parameter at the control panel by changing “D7 config” from 1 into 2.
11.1.5. G
AS TYPE SELECTION
Settings for gas types: natural gas, propane or butane-propane mixture (B/P).
P4 BD Gas type (0=standard, 1=propane , 2=B/P) (display D8).
This parameter is set 0 for the common used gas types such as natural gas G20 or G25.
By setting this parameter 1 for propane, fan speed is reduced.
Set this parameter 2 for B/P.
0 = standard gas (e.g: natural gas)
1 = propane
2 = B/P
By each setting, the relevant Soft start settings are automatically adjusted, depending on its main setting P4BE ,
see next section § 11.1.6.
Remark: For the S-CB Px 120 it is not necessary to use P4BD because the air restrictor kit for
propane/butane must be used.