Xylem EPR IM Electric heater-circulator unit EPR (obsolete) - Manual (Page 11)

11
Instruction manual Laing Electric heater circulator unit
www.lainginc.com
passes the information on to the microprocessor. The microprocessor then
activates the solid state relays which in turn activate the heating elements
according to the jumper selected program. An independent sensor C also
monitors the temperature of the feed line water and switches the pump off
when the temperature exceeds a pre-set temperature.
A further sensor D monitors the temperature of the solid state relays and
turns off the heating elements in case of overheating.
A special control logic verifies the rotation of the circulator and prevents
the heating elements from being turned on if the circulator is not running.
The safety temperature limiter turns the heating elements off permanently - in-
dependent of the electronic control - when the temperature exceeds 194°F.
Design of the Main Printed Circuit Board
(See also page )
Fastening
points
Processor
Connector for
solid state relays, power supply and sensors.