tekmar 265 Boiler Control User Manual

Page 24

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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 Ohms, is essential
to properly test the wiring and sensors.

Boil

Sup

Com

–

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 (13 and 14) 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 Com Dem terminals (29 and 30). When the boiler
demand device calls for heat, a voltage between 20 and 260 V (ac)
should be measured at the terminals. When the boiler demand
device is off, less than 5 V (ac) should be measured.

DHW Demand

If a DHW demand is used, measure the voltage between the
Setp / DHW and the Com Dem terminals (31 and 30). When the
DHW demand device calls for heat, a voltage between 20 and
260 V (ac) should be measured at the terminals. When the DHW
demand device is off, less than 5 V (ac) should be measured.

Setpoint Demand

If a setpoint demand is used, measure the voltage between the
Setp / DHW and the Com Dem terminals (31 and 30). When the
setpoint demand device calls for heat, a voltage between 20 and
260 V (ac) should be measured at the terminals. When the setpoint
demand device is off, less than 5 V (ac) should be measured.

External Input

If an external input is used, measure the voltage between the
Com – and the Out + terminals (1 and 4). When the external input
device calls for heat, a voltage between 0 and 10 V (dc) should be
measured at the terminals.

Power

103.5 to 126.5 V (ac)

20 to 260 V (ac)

Boil

Dem

Com

Dem

20 to 260 V (ac)

Com

Dem

Setp/

Dem

2 3

Com

–

Boil

Ret

Out

Boil

Sup

500Ω

0 - 10 V (dc)

0 - 20 mA