Wiring Guide

11 of 12 © 2009 W 423 - 03/09
Testing tN4 Network Terminals 58 - 65
To test each tN4 Network, check the wires for continuity.
1. Disconnect the two wires (tN4 and C) at one end and
connect them together.
2. Go to the other end of the wires and disconnect them.
3. Using an electrical test meter, check for continuity.
Testing tekmar Sensors Terminals 66 - 70
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 070.
Testing DHW Zone Valve Terminals 71, 72
1. Ensure that the control is set to operate the DHW zone
valve output.
2. Remove the front cover from the control.
3. Press the Test Button.
4. When “DHW” is displayed in the LCD, use an electri-
cal test meter to measure the (ac) voltage between the
C and Vlv terminals (71-72). The reading should be
24 V (ac) + / – 10%.
5. If power is not present:
•
• Check the power supply to the Zone Manager and the
field replaceable fuse for the transformer on the Zone
Manager.
•
• If the fuse is blown, determine the cause of the failure
before replacing the fuse.
•
• Also check the Plug in connections on the underside of
the control.
6. When “DHW” is not displayed in the LCD, use an
electrical test meter to measure the (ac) voltage between
the C and Vlv terminals (71-72). The reading should be
0 V (ac).
Testing Auxiliary 24 V Power Supply Terminals 73 - 74
1. Remove the front cover from the control.
2. Use an electrical test meter to measure (ac) voltage
between the Power R and Power C terminals 74 and
73 The reading should be 24 V (ac) + / – 10%.
3. If power is not present:
• Check the power supply to the Zone Manager and the
field replaceable fuse for the transformer on the Zone
Manager.
• If the fuse is blown, determine the cause of the failure
before replacing the fuse.
• Also check the Plug in connections on the underside of
the control.
Testing the DHW or Setpoint Demand Terminals 75 - 78
1. Remove the front cover from the control.
2. Use an electrical test meter to measure (ac) voltage
between the DHW Demand terminals (75-76) or the
Setpoint Demand terminals (77-78).
•
• When the demand device is on a voltage between 20 and
260 V (ac) should be measured between terminals and
the LCD should display “DEM” and “DHW” or “SETP”.
•
• When the demand device is off, less than 5 V (ac) should
be measured between the terminals.