application, all compressor relays and related functions will track with their associated DIP switch 2 on S1.
NIGHT LOW LIMIT (NLL) STAGED HEATING — In NLL staged Heating mode, the override (OVR) input becomes active and is recognized as a call for heating and the control will immediately go into a Heating Stage 1 mode. With an additional 30 minutes of NLL demand, the control will go into Heating Stage 2 mode. With another additional 30 minutes of NLL demand, the control will go into Heating Stage 3 mode.
Units with WSHP Open Multiple Protocol —
The WSHP Open
SCHEDULING — Scheduling is used to start/stop the unit based on a time period to control the space temperature to spec- ified occupied heating and cooling set points. The controller is defaulted to control by occupied set points all the time, until ei- ther a time schedule is configured with BACview6, Field Assis- tant,
Occupancy Schedules — The controller will be occupied 24/7 until a time schedule has been configured using either Field Assistant,
NOTE: This point must be enabled in order for the
Schedule_schedule — The unit will operate according to the schedule configured and stored in the unit. The schedule is accessible via the BACview6 Handheld tool,
Occupancy Input Contact — The WSHP Open controller has the capability to use an external dry contact closure to deter- mine the occupancy status of the unit. The Occupancy Sched- ules will need to be disabled in order to utilize the occupancy contact input.
NOTE: Scheduling can only be controlled from one source.
BAS (Building Automation System) On/Off — A BAS system that supports network scheduling can control the unit through a network communication and the BAS scheduling function once the Occupancy Schedules have been disabled.
NOTE: Scheduling can either be controlled via the unit or the BAS, but not both.
INDOOR FAN — The indoor fan will operate in any one of three modes depending on the user configuration selected.
Fan mode can be selected as Auto, Continuous, or Always On. In Auto mode, the fan is in intermittent operation during
both occupied and unoccupied periods. Continuous fan mode is intermittent during unoccupied periods and continuous dur- ing occupied periods. Always On mode operates the fan con- tinuously during both occupied and unoccupied periods. In the default mode, Continuous, the fan will be turned on whenever any one of the following is true:
•The unit is in occupied mode as determined by its occu- pancy status.
•There is a demand for cooling or heating in the unoccu- pied mode.
•There is a call for dehumidification (optional).
When power is reapplied after a power outage, there will be a configured time delay of 5 to 600 seconds before starting the fan. There are also configured fan delays for Fan On and Fan Off. The Fan On delay defines the delay time (0 to 30 seconds; default 10) before the fan begins to operate after heating or cooling is started while the Fan Off delay defines the delay time (0 to 180 seconds; default 45) the fan will continue to op- erate after heating or cooling is stopped. The fan will continue to run as long as the compressors, heating stages, or the dehu- midification relays are on. If the SPT failure alarm or conden- sate overflow alarm is active; the fan will be shut down imme- diately regardless of occupancy state or demand.
Fan Speed Control (During Heating) — Whenever heat is re- quired and active, the control continuously monitors the sup-
Fan Speed Control (During Cooling) — Whenever mechani- cal cooling is required and active, the control continuously monitors the
COOLING — The WSHP Open controller will operate one or two stages of compression to maintain the desired cooling set point. The compressor outputs are controlled by the PI (propor-
•Cooling is set to Enable.
•Heating mode is not active and the compressor time guard has expired.
•Condensate overflow input is normal.
•If occupied, the SPT is greater than the occupied cooling set point.
•Space temperature reading is valid.
•If unoccupied, the SPT is greater than the unoccupied cooling set point.
•If economizer cooling is available and active and the economizer alone is insufficient to provide enough cool- ing.
•OAT (if available) is greater than the cooling lockout temperature.
If all the above conditions are met, the compressors will be energized as required, otherwise they will be deenergized. If cooling is active and should the SAT approach the minimum SAT limit, the fan will be indexed to the next higher speed. Should this be insufficient and if the SAT falls further (equal to the minimum SAT limit), the fan will be indexed to the
41