SAUTER flexotron®400 - RDT410
Control modes
P100012103
15
External setpoint
It is possible to use an external Ni1000 setpoint device. The setpoint device is
connected between terminal 10 SPI and the reference for the analogue inputs,
. For more information on configuration and setpoint reading, see chapters 7
and 10.
Universal input UI1
Electric heating
If the RDT410 is used to control electric heating UI1 is used for the high
temperature limit switch. Connect and configure as a digital input. The input is
normally closed. Whenever the running mode switches to “Off”, (normal
shutdown) the heating output will be shut down immediately but the fan will run
on for a further 3 minutes to cool the heater. On activation of the high
temperature limit, the heating output will be shut down immediately and there will
be no cool-down period.
Wiring suggestion for high temp limit when using electric heating. Drawn with
high temp limit activated.
It is important that the high temperature thermostat is hardwired to disconnect
the power to the heater to ensure that the heating is shut down when the
thermostat is activated even if the controller RDT410 should be faulty.
Water heating
When controlling a water heater, UI1 can, when necessary, be used for a frost
protection sensor. Connect and configure as an analogue input. The frost
protection function can be tied to either of the analogue outputs.
The heater return water temperature is monitored by the frost protection sensor.
Should the temperature at the frost protection sensor fall below 12°C an internal,
proportional signal is generated that is used to force the heating valve open to try
and prevent freeze-up of the heater.
The frost protection signal (“Internal signal”) will increase linearly to 100 % at 7°C
at which point the frost protection alarm is triggered. The fan will then be shut
down and the controller will go into shutdown mode.
12°C
“Internal signal”
0 %
100 %
Prop.band
7°C
