tekmar 264 Boiler Control - Manual (Page 20)

© 2008 D 264 - 12/08 20 of 32
2 1
Com Boil
Sup
Boiler Return Sensor
If a boiler return sensor is used, connect the two wires from the Boiler Return Sensor
071 to the Com and Boil Ret terminals (1 and 3). The boiler return sensor is used by
the control to measure the boiler return water temperature.
UnOccupied Switch
If an external timer (tekmar Timer 032) or switch is used, connect the two wires from
the external switch to the Com and UnO Sw terminals (1 and 5). When these two
terminals are shorted together, the control registers an UnOccupied signal.
10 9
Power
L N
103.5 to 126.5 V (ac)
7 6
Com
Dem
Boil
Dem
20 to 260 V (ac)
Test The Sensors
In order to test the sensors, the actual temperature at each sensor
location must be measured. A good quality digital thermometer with
a surface temperature probe is recommended for ease of use and
accuracy. Where a digital thermometer is not available, a spare sensor
can be strapped alongside the one to be tested and the readings
compared. Test the sensors according to the instructions in the Data
Brochure D 070.
Test The Power Supply
Make sure exposed wires and bare terminals are not in contact with
other wires or grounded surfaces. Turn on the power and measure the
voltage between the Power L and Power N terminals (10 and 9) using an
AC voltmeter, the reading should be between 103.5 and 126.5 V (ac).
Test the Powered Inputs
Boiler Demand
If a boiler demand is used, measure the voltage between the
Boil Dem and the Com Dem terminals (6 and 7). When the boiler
demand device calls for heat, you should measure between 20 and
260 V (ac) at the terminals. When the boiler demand device is off,
you should measure less than 5 V (ac).
1
Com
2
Boil
Sup
3
Boil
Ret
4
Out
5
UnO
Sw
STEP FIVE
——————
TESTING THE WIRING
General
Each terminal block must be unplugged from its header on the control before power is applied for testing. To remove the terminal
block, pull straight down from the control.
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) and at least 0 - 2,000,000 Ω, is essential to
properly test the wiring and sensors.
2 1 3 4
Com Boil
Sup
Boil
Ret
Out