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Off: Turn everything off. The Heating Percent Cmd is set to 0%.
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Max: Open the heating valve. The Heating Percent Cmd is set to 100%.
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Hold: Hold the outputs at their current position.
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Water Flush: The valve is opened to the Water Flush Position.
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Limited Max: The valve is opened to the Limited Max Value. This state may be used for unoccupied heating.
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T Control: Open the heating valve and adjust the output to control the Process Variable. If the Process Variable is reliable, the module controls the output to maintain the Process Variable at the Setpoint. The Heating Percent Cmd is adjusted between 0% and 100%.
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LL-T Control: Open the heating valve and adjust the output to control the Limit Variable. If the Limit Variable is reliable, the module controls the output to maintain the Limit Variable at the Limit Setpoint. The Heating Percent Cmd is adjusted between 0% and 100%.
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Low OA Temperature: The valve is opened to the Low OA Temperature Position when the Protect-T is less than the Protect-Tsp.
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Failsoft: The valve is opened to the Failsoft Value. This state may be used when the control temperature is unreliable.
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Low OA Temperature Startup: This mode activates the T Control state section, but limits the rate at which the valve can close so that the unit can safely come into control (typically used for 100% OA units with low OA temperatures at startup).
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Remain In Control: Modulate the valve to control the Limit Variable to the Limit Setpoint. If the Limit Variable is reliable, the module controls the output to maintain the Limit Variable at the Limit Setpoint. This mode should only be used as a shutdown strategy to add energy to the duct when the fan is off. It should not be used for general temperature control.
OA Temperature isReliable |
Low Limit Process Variable isReliable |
PID Tuning Reset |
Mode |
State |
---|---|---|---|---|
* |
* |
* |
Off |
Off |
Max |
Max |
|||
T Control |
T Control |
|||
LL-T Control |
LL-T Control |
|||
Reset 1st PID |
Hold |
T Control |
||
Reset 2nd PID |
Hold |
LL-T Control |
||
* |
Hold |
Hold |
||
True |
* |
* |
Low OA Temperature |
Low OA Temperature |
False |
* |
* |
Low OA Temperature |
Failsoft |
* |
* |
* |
Water Flush |
Water Flush |
Limited Max |
Limited Max |
|||
Failsoft |
Failsoft |
|||
Low OA Temperature Startup |
T Control |
|||
True |
* |
Remain In Control |
Remain In Control |
|
False |
* |
Remain In Control |
Failsoft |