tekmar 274 Boiler Control - Manual (Page 24)

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Testing tekmar Sensors Terminals 2 – 6
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 Relay 1 – 4 Terminals 7 – 14
1. Shut off power to the control and the boiler circuit or
boiler pump circuit.
2. Remove the bottom cover from the control. Disconnect
the wiring from the Relay contacts (terminals 7 – 14).
3. Apply power to the control and press the Test button.
4. Use an electrical test meter and check for continuity
between terminals 7-8, 9-10, 11-12 and 13-14.
If the relay is set to boiler ignition:
When the appropriate boiler symbol is displayed in the
LCD, there should be continuity.
When the appropriate boiler symbol is not displayed in
the LCD, there should be no continuity. •
•
If the relay is set to boiler pump:
When the appropriate boiler pump symbol is displayed
in the LCD, there should be continuity.
When the appropriate boiler pump symbol is not displayed
in the LCD, there should be no continuity.
5. Reconnect the wires to the Relay contacts, install the
bottom cover on the control and reapply power to the
boiler circuit or boiler pump circuit.
•
•
•
Testing C.A. / Alert Relay Terminals 15 – 16
1. Shut off power to the control and the boiler circuit or
boiler pump circuit.
2. Remove the bottom cover from the control. Disconnect the
wiring from the C.A. / Alert contact (terminals 15 – 16).
3. Apply power to the control and press the Test button.
4. Use an electrical test meter and check for continuity
between terminals 15 – 16.
If the relay is set to Combustion Air Damper:
When the Combustion Air Damper symbol is displayed
in the LCD, there should be continuity. •
When the Combustion Air Damper symbol is not displayed
in the LCD, there should be no continuity.
If the relay is set to Alert:
When the Alert symbol is displayed in the LCD, there
should be continuity.
When the Alert symbol is not displayed in the LCD, there
should be no continuity.
5. Reconnect the wires to the C.A. / Alert contacts, install
the bottom cover on the control and reapply power to
the Combustion Air Damper or Alert circuit.
•
•
•
Testing DHW and Primary Pumps Terminals 17 - 18
Testing the Input Power Terminals 19 – 20
1. Remove the front and bottom cover from the control.
2. Use an electrical test meter to measure (ac) voltage
between the Input Power L and N terminals (19 and 20).
The reading should be 115 V (ac) + / – 10% and the LCD
should be lit and show some segments.
1. Remove the front and bottom covers from the control.
2. Press the Test Button.
3. When the Primary Pump 1 symbol is displayed in the LCD,
use an electrical test meter to measure the (ac) voltage
between the Primary Pump 1 terminal and Neutral (18-
20). The reading should be 115 V (ac) + / – 10%.
If DHW Mode is enabled:
When the DHW Pump symbol is displayed in the LCD, use
an electrical test meter to measure the (ac) voltage between
the DHW Pump terminal and Neutral (17-20). The reading
should be 115 V (ac) + / – 10%.
If Pump Sequencer is enabled:
When the Primary Pump 2 symbol is displayed in the LCD,
use an electrical test meter to measure the (ac) voltage
between the Primary Pump 2 terminal and Neutral (17-20).
The reading should be 115 V (ac) + / – 10%.
3. If power is not present and the LCD is off:
Check the circuit that supplies power to the Control.
Make sure exposed wires and bare terminals are not in
contact with other wires or grounded surfaces. •
•