A good quality electrical test meter, capable of reading from at least 0 - 300 V (ac) and at least 0 - 2,000,000 ohm, is essential to properly test the wiring and sensors.
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 recom- mended for ease of use and accuracy (FIG. 33). 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 INS7141.
FIG. 33 |
TEST THE POWER SUPPLY
Make sure exposed wires and bare terminals are not in con- tact 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) (FIG. 34) using an AC volt- meter, the reading should be between 103.5 and 126.5 V (ac).
V | 9 | 10 | 103.5 to 126.5 V (ac) | |
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| FIG. 34 | |
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) (FIG. 35). When the boiler demand device calls for heat, you should measure between 20 and 260 V (ac) at the ter- minals. When the boiler demand device is off, you should measure less than 5 V (ac).
DHW Demand
If a DHW demand is used, measure the voltage between the Setp / DHW and the Com Dem terminals (8 and 7) (FIG. 35). 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.
Set Point Demand
If a set point demand is used, measure the voltage between the Setp / DHW and the Com Dem terminals (8 and 7) (FIG. 35). When the set point demand device calls for heat, you should measure between 20 and 260 V (ac) at the termi- nals. When the set point demand device is off, you should measure less than 5 V (ac).
FIG. 35
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, you should measure between 0 and 10 V (dc) at the terminals.
FIG. 36
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