Bradford-White Corp 9kW, 900kW service manual Display, Setup Of The Temperature Controller, Example

DISPLAY

Once power is applied to the temperature controller the display will countdown from 210 until the display reads zero. All outputs are de-energized at this time. This countdown process will repeat each time main power is interrupted. To avoid viewing this entire countdown, press the Select key. The display will now show normal readings: load (sensed) temperature and stages energized. At any time during the programming procedure, the display will revert back to showing the sensed temperature and stage status indication 60 seconds after the last programming key is pushed.

SETUP OF THE TEMPERATURE

CONTROLLER

Each stage on the controller has its own independent set point and differential which are determined by the programming keys. Each stage of heating is de-energized as the sensed temperature reaches the programmed set point. Each available stage of heating is energized as the sensed temperature reaches the set point minus the differential.

EXAMPLE:

Using stage one of the control as an example, the corresponding load would be energized and de-energized at the following temperatures based on the programmed settings.

Settings

Set point: 160o F

Differential: 8o F

Output Energized

Stage One: Energized at 152o F

Output De-energized

Stage One: De-energized at 160o F

Each available stage of operation must be programmed with a set point and a differential. If two stages are programmed with the same set

point and differential the control will sequence both stages on and off with only a slight delay between switching of the stages. The control is normally programmed with a few degrees difference between the set point of each stage to sequence individual stages on as required by demand. This will allow input to be balanced to system demand. The exact settings will be determined by your system hot water requirements.

Based on your system requirements, determine the set point and switching differential for each stage of operation and enter into the worksheet below.

Programming Worksheet

Stage 1:
Set Point 1 ___________	Off at ___________
Differential 1 ________	On at __________
Stage 2:
Set Point 2 ___________	Off at ___________
Differential 2 ________	On at __________
Stage 3:
Set Point 3 ___________	Off at __________
Differential 3 ________	On at _________
Stage 4:
Set Point 4 ___________	Off at __________
Differential 4 ________	On at _________

These values will be programmed into the temperature controller.

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