The water heater uses an optional adjustable electronic temperature control to provide staged ON/OFF control of the electric heating elements. Operation is based on temperature input from an immersion temperature sensor. The sensor is a positive coefficient platinum thermistor. The sensor is placed in a well located above the heating elements it is controlling. A liquid crystal display is provided to indicate sensed temperature and operating parameters. The temperature control may operate in as many as four stages of control. For more stages of operation, multiple electronic temperature control sequencers are installed and wired to operate in series.
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FIG. | 20 | Electronic | Temperature | Control | |||
Digital Display and Programming Keys |
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SPECIFICATIONS
Set Point Adjustment Range: Max setting 220° F (105° C).
Temperature Accuracy: +/- 1° F.
Display Resolution: 1° F via Liquid Crystal
Display (LCD). Sensor: Thermistor 4.8 ohms/° F.
Operating Humidity: 5 - 95% RH
Noncondensing.
Operating Ambient Temperature: -30° to 125° F.
Access to the control is achieved by opening the hinges control panel door covering the electrical components. Four programming keys are provided to program set point and differential values for each stage and to control the display. The four keys are Select, Up arrow, Down arrow and Enter.
Select Key - Sequentially prompts the user as to what parameter is being displayed: set point, differential, stage energized, operation mode (heat), indication of assigned stage (1,2,3). Once the last parameter value has been viewed, pressing the Select key will display the control values again from the beginning of the display loop.
Up and Down Arrow Keys - Allow the displayed parameter to be increased or decreased. After pressing the Select key, a control value can be changed by using the Arrow keys. Control values will be increased or decreased by 1° F for each time the Arrow keys are depressed.
Enter Key - Places the new value into the memory of the microprocessor.
IMPORTANT: A control value or operation will not be entered in the memory of the microprocessor until the Enter key is pressed.
Control values and operation selection will remain in the device memory even after power is removed.
Select and Enter Keys simultaneously
pressed - Changes operation mode of the control from heat to cool mode. DO NOT CHANGE THIS SETTING. This control must always be in the “HEAT” position for proper operation of the water heater.
When all stages have been programmed the display will revert back to sensed temperature and load energized status.
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