Pressing the Back key will return you to the Heat Source display. The up and down arrow keys can be used to scroll the cursor up and down to the various heat sources (boilers or water heaters) at this location. To the right of each heat source displays the operational status of the individual appliance. Pressing the Select key when the cursor is on a specific heat source displays the parameters for this boiler or water heater. Pressing the Change softkey takes you to a screen displaying the six adjustable points for the boiler or water heater. Use the up and down arrow keys to move the cursor to each point. Use the + and - softkeys to adjust the setting pressing Select softkey to enter the revised setting into memory. Pressing the Back button will return you to the screen displaying the parameters for this Boiler or Water Heater. Pressing the Back button will return you to screen displaying the Heat Source(s) and the presence of an Optional Sequencer, if equipped.
FIG. 57 Command Display Data Screen
OUTDOOR RESET FUNCTION
SELECTIONS
(Optional on Heating Boilers Only)
As an option, the Excel 10 control may be equipped with an outdoor reset function. This function uses a sensor to measure the outdoor temperature and automatically adjust the boiler set point temperature to compensate for colder outdoor temperatures. O.A. Min, Max, SetPoint and Setpoint Temp are changeable points from the Command Display. The additional values required by the Excel 10 to properly operate the reset function should be specified at the time a boiler is ordered. If specific settings are not available the default values will be programmed into the Excel 10 at the factory. The operating parameters for the reset function are:
O.A. Lockout — The maximum outdoor air temperature where the boiler will continue to operate. When the outdoor temperature rises above this setting, no heat should be needed for the building and the boiler will lockout and not fire. The default setting if not specified is 70.0°F (21.1°C). This setting should be specified at the time the boiler is ordered.
O.A. Max — The warmest outdoor air temperature where the boiler reset function will begin to function and operate the boiler at the initial set point temperature. The boiler set point will increase based on a corresponding drop in outdoor temperature below this temperature. The default setting if not specified is 60.0°F (15.6°C).
O.A. Min — The coldest outdoor air temperature where the boiler reset function will reach a maximum boiler water temperature (Max. SetPoint). No additional reset (increase) in boiler temperature will occur past this point as outdoor temperature continues to drop lower. The default setting if not specified is 10.0°F
O.A. Temp. — A display of the outdoor air temperature as sensed by the outdoor air sensor.
Max. SetPoint — The maximum water temperature that the boiler or water heater may be set to operate at. The default setting if not specified is 220.0°F (104.4°C). This setting is a Changeable Point from the Command Display.
| TABLE - V |
| Status Point Alarm Modes: |
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Low H2O Flow: | Low water or flow condition exists. |
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Low Air Press: | Low air condition exists. |
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Block Drain: | Blocked condensate drain exists. |
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Block Flue: | Blocked flue or louver proving switch failed to prove. |
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Gas Press Fail: | Low or high gas pressure condition exists. |
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Flame Fail: | Hard lockout on a flame failure signaled from the ignition control. |
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Soft Lockout: | Wait period for the ignition control to recover from soft lockout conditions. |
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Over Temp: | Indicates that a higher than programmed temperature has been reached. |
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