4.2.4
Control
On/off control
The heat input varies between the minimum and the maximum values
on the basis of the flow temperature set on the boiler. It is possible to
connect a 2-wire on/off thermostat or a power stealing thermostat to the
boiler.
Modulating control
The heat input varies between the minimum and the maximum values
on the basis of the flow temperature determined by the modulating
controller. The boiler output can be modulated with an appropriate
modulating controller.
Analogue control (0 - 10 V)
The heat input varies between the minimum and the maximum values
on the basis of the voltage present at the analogue input.
4.2.5
Regulating the water temperature
The boiler is fitted with an electronic temperature control with a flow and
return temperature sensor. The flow temperature can be adjusted between
20°C and 90°C. The boiler modulates back when the set flow temperature
is reached. The switch-off temperature is the set flow tempe 5°C.
4.2.6
Protection against shortage of water
The boiler is fitted with low water level protection based on temperature
measurements. By modulating back when the water flow threatens to
become insufficient, the boiler remains operational as long as possible.
The boiler issues a warning in the event of no or too little water. With an
insufficient flow ΔT ≥ 25 K or too great an increase in the heat exchanger
temperature sensor, the boiler goes into blocking mode.
4.2.7
Water flow
The modulating control of the boiler limits the maximum difference
between the flow temperature and return temperature. In addition, a heat
exchanger temperature sensor is mounted to monitor the minimum water
flow. This limits the maximum increase in the heat exchanger temperature
and monitors the maximum temperature difference between the flow,
return and heat exchanger temperatures. As a result, the boiler is not
affected by low water flow.
4.2.8
Hydraulic pressure sensor
The hydraulic pressure sensor records the water pressure in the boiler.
Change the threshold value for the hydraulic pressure sensor using
parameter AP006.
For more information, see
Parameters - FSB-WHB-HE-150-300, page 50
Changing the parameters, page 49
4.2.9
Air pressure differential switch
The air pressure differential switch is a protection against a blocked trap or
blocked air supply/flue gas outlet.
Before start-up and when the boiler is in operation, the air pressure
differential switch APS measures the difference in pressure between the
measuring points on the condensate collector p
+
and the air box p
-
. If the
pressure difference is greater than 6 mbar, then the boiler will lock out.
After eliminating the cause of the breakdown, the boiler can be unlocked.
4 Description of the product
7625116 - v.06 - 17102018
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