Heatcraft Refrigeration Products 25001401, Инструкция по установке и эксплуатации

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20
Power Failures
In the event of a power failure, Beacon II will automatically close the
expansion valve to prevent refrigerant from migrating throughout the
system. After power returns, with 24 VAC at the board, the system
will restart in the cooling mode after the four-minute hold off period.
Spare Sensor Terminals
Beacon II provides a set of input terminals for customers who may
want to monitor an additional temperature or items such as Product
Temperature. This input terminal requires a signal from a thermistor
which meets the temperature/resistance values in Table 1 on page
21.
If a product temperature simulator is used, it must meet the
resistance/temperature specification listed in Table 1. The
temperature range for this input is –30°F to 140°F. Sensors on the
Beacon II system, as supplied, will not simulate product temperature.
This input can be monitored on the LED display by using the
“
MONITOR
” button and scrolling to SPt . The values displayed will
be the temperature of the spare sensor.
Power Failures
Checking Sensors
DO NOT REMOVE SENSORS FROM EVAPORATORS FOR CHECKING.
Use the monitor button to display the value the sensors are reading
on the LED (suction temperature
SCt , defrost temperature dFt , or
room temperature). Compare this value to the measured value with
a thermometer at each of these points. If they do not match, change
the sensor.
OR
The sensors can be checked for their proper operation by placing it
in a cup of ice water. Stir the ice water and measure the resistance
of the sensor. At 32°F the resistance should be 32,650 ohms. If it is
higher or lower by 1,000 ohms approximately, the sensor should be
replaced.