Wiring Guide

7 of 8 © 2008 W 441 - 12/08
Mix Sensor (tekmar 082)
Connect the two wires from the Mix Supply Sensor to the
Com and Mix terminals. The Mix Supply Sensor is used by
the control to measure the mix supply temperature.
441
Sensor mounted in
Mix Supply pipe
56
Com Mix
+
1234
R C tN4 Pmp
###
Troubleshooting the Wiring
General
The following tests are to be performed using standard
testing practices and procedures and should only be carried
out by properly trained and experienced persons.
A good quality electrical test meter, capable of reading from
at least 0-300 V (ac), 0-30 V (dc), 0-2,000,000 Ohms, and
testing for continuity is essential to properly test the wiring
and sensors.
For an explanation on the use of the Test Button, the ‘Test’
sequence or any error messages, refer to the Data Brochure
of the tN4 System Control.
Testing the Control
Testing the Power
The Power LED is green when 24 V (ac) is applied to the R and the C terminals. Use a voltmeter to check for 24 V (ac)
+/- 10% on terminals R and C.
Testing the tN4 Communication
The tN4 Bus LED is green when the 441 detects communication. If the tN4 Bus LED is off, ensure that the tN4 and C
wires are properly terminated on the 441 and at the device on the other end of the wires. The tN4 and C wires are polarity
sensitive.
To check the tN4 and C wires, disconnect the wires on one end and connect them together using a wire nut. Then measure
the other end of the wires using the continuity check on a digital multimeter.
Testing the System Pump
The System Pump LED is green when the Pump contact is energized. Use a voltmeter to check for 24 V (ac) +/- 10%
between the Pump and the C terminal.
Testing tekmar Sensors
To test the sensors, the actual temperature at each sensor location must be measured.
•
• Use a good quality digital thermometer with a surface temperature probe for ease of use and accuracy. Where a digital
thermometer is not available, strap a spare sensor alongside the one to be tested and compare the readings.
•
• Disconnect each sensor from the control.
•
• Test the sensors resistance according to the instructions in the sensor Data Brochure D 082.