Sequence Of Operation - valent VPR Series Controls Instruction Operation & Maintenance

Sequence of Operation

1. OCCUPANCY
1.1. The controller shall enable occupancy under any one of the following conditions.
A. Internal time clock determines occupancy is true.
B. Dry contact is closed (internal time clock must be disabled).
C. BAS communication signal determines occupancy is true.
D. Timed override signal through space temperature sensor is true.
E. Optimal start sequence enabled.
1.2. The controller shall perform the following functions in the occupied mode.
A. Modulate the outdoor air damper and return air damper to the minimum position (return air damper modulates
inversely to the outdoor air damper).
B. Enable the supply fan upon closure of the outdoor air damper end switch.
C. Enable the exhaust fan 30 seconds after closure of the supply fan pressure switch.
1.3. The controller shall disable occupancy under any one of the following conditions.
A. Internal time clock determines occupancy is false.
B. Dry contact is opened (internal time clock must be disabled).
C. BAS communication signal determines occupancy is false.
D. Timed override signal through space temperature sensor is false.
1.4. The controller shall perform the following functions after occupancy is disabled.
A. Cooling, dehumidification, heating, or economizer shall be disabled.
B. After 30 seconds (adj.) the supply fan shall be disabled.
C. Outdoor air damper shall be de-energized and fail closed.
D. Return air damper shall be de-energized and fail open.
2. NIGHT SETBACK
2.1. Unit shall enable night setback under any one of the following conditions.
A. Relative humidity in the space is greater than 55% (adj.) OR dewpoint in the space is greater than 53°F (adj.).
B. Space temperature is greater than 80°F (adj.).
C. Space temperature is less than 60°F (adj.).
2.2. The controller shall perform the following functions in the night setback.
A. Supply fan shall enable.
B. Temperature control sequence shall enable.
2.3. The controller shall disable night setback under any one of the following conditions.
A. Space conditions are satisfied.
B. Internal time clock in microprocessor controller determines unoccupied mode.
C. Dry contact for occupied mode is closed.
3. TEMPERATURE CONTROL
3.1. The controller shall enable the temperature control sequence when any of the following conditions are met.
A. Occupancy is true.
B. Night setback mode enabled.
3.2. The supply air temperature setpoint shall be determined by the following inputs.
A. [Supply air control] User-defined supply air temperature setpoint.
B. [Space temperature and humidity control with supply air reset] PID loop driven by user-defined space
temperature setpoint within the supply minimum and maximum setpoints.
3.3. The controller shall enable the following modes of operation in order to maintain the supply air temperature setpoint.
A. Heating (if equipped).
B. Energy recovery (if equipped).
C. Economizer (if equipped).
D. Cooling.
Valent Controls IOM 63 IOM-C1-0616
Part Number 474626