Download RWF50.2 and RWF50.3 Compact universal controllers User Manual

5
Operating modes
5.1 Low-fire operation
Low-fire operation means that only small amounts of heat are drawn from the boiler.
Using relay K1 Burner release, the 2-position controller ensures control to the setpoint
by switching the burner on and off like a thermostat.
Thermostat function
This mode of control is known as the thermostat function. An adjustable switching
differential ensures that the burner’s switching frequency can be selected, aimed at
reducing wear.
Modulating and 2-stage operation:
Actual value lies between switch-on
threshold HYS1 and switch-off threshold
HYS3.
Heating controller
ON
OFF
7866d03e/1011
Figure 6: Control sequence of heating controller
Cooling controller
If the controller is set to cooling mode, temperature limits HYS4 and HYS6 apply. In that
case, relay K1 Burner release is used for controlling the cooling equipment.
Modulating and 2-stage operation:
Actual value lies between switch-on
threshold HYS4 and switch-off threshold
HYS6.
ON
OFF
7866d04e/1011
Figure 7: Control sequence of cooling controller
21/64
Building Technologies Division
Infrastructure & Cities Sector
User Manual RWF50...
5 Operating modes
CC1U7866en
25.07.2014