Carrier 50PTH, PTV specifications Units with WSHP Open Multiple Protocol

Output EH1, EH2, Fan Enable, and Fan Speed will be ON if the G input is not active during Emergency Heat mode. COOLING STAGE 1 — In Cooling Stage 1 mode, the Fan Enable, compressor and RV relays are turned on immediately. If configured as stage 2 (DIP switch set to OFF) then the com- pressor and fan will not turn on until there is a stage 2 demand. The Fan Enable and compressor relays are turned off immedi- ately when the Cooling Stage 1 demand is removed. The con- trol reverts to Standby mode. The RV relay remains on until there is a heating demand. If there is a master/slave or dual compressor application, all compressor relays and related func- tions will track with their associated DIP switch 2 on S1.

COOLING STAGE 2 — In Cooling Stage 2 mode, the Fan Enable, compressor and RV relays remain on. The Fan Speed relay is turned on immediately and turned off immediately once the Cooling Stage 2 demand is removed. The control reverts to Cooling Stage 1 mode. If there is a master/slave or dual compressor 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 ac- tive and is recognized as a call for heating and the control will immediately go into a Heating Stage 1 mode. With an addition- al 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 multi-protocol controller will control me- chanical cooling, heating and waterside economizer outputs based on its own space temperature input and set points. An optional CO2 IAQ (indoor air quality) sensor mounted in the space can maximize the occupant comfort. The WSHP Open controller has its own hardware clock that is automatically set when the heat pump software is downloaded to the board. Oc- cupancy types are described in the scheduling section below. The following sections describe the functionality of the WSHP Open multi-protocol controller. All point objects referred to in this sequence of operation will be referenced to the objects as viewed in the BACview6 handheld user interface.

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, i-Vu®Open, or a third party control system to enable/dis- able the BAS (Building Automation System) on/off point. The local time and date must be set for these functions to operate properly. The occupancy source can be changed to one of the following:

Occupancy Schedules — The controller will be occupied 24/7 until a time schedule has been configured using either Field Assistant, i-Vu Open, BACview6 or a third party control sys- tem to enable/disable the BAS on/off point. The BAS point can be disabled by going to Config, then Unit, then Occupancy Schedules and changing the point from enable to disable then clicking OK.

NOTE: This point must be enabled in order for the i-Vu Open, Field Assistant, or BACview6 control system to assign a time schedule to the controller.

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, i-Vu Open, or Field Assistant control system. The daily schedule consists of a start/stop time (standard or 24-hour mode) and seven days of the week, starting with Monday and ending on Sunday. To enter a daily schedule, navigate to Config, then Sched, then enter BACview6 Admin Password (1111), then go to schedule_schedule. From here, enter either a Weekly or Excep- tion schedule for the unit.

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.

Automatic Fan Speed Control — The WSHP Open controller is capable of controlling up to three fan speeds using the ECM (electronically commutated motor). The motor will operate at the lowest speed possible to provide quiet and efficient fan op- eration with the best latent capability. The motor will increase speed if additional cooling or heating is required to obtain the desired space temperature set point. The control increases the motor's speed as the space temperature rises above the cooling or below the heating set point. The amount of space tempera- ture increase above or below the set point required to increase the fan speed is user configurable in the set point.

The Low Fan speed range is configured by the width of the Yellow (for cooling) and Light Blue (for heating) setpoint bands. The fan will operate at low speed as long as the space temperature remains within the yellow or light blue band range. The Medium Fan speed range is determined by the Or- ange and Dark Blue setpoint band. The fan will operate at me- dium speed when the space temperature enters this range. If the space temperature rises or falls into the red range, the fan will operate at High Fan speed.

As the temperature returns toward setpoint, a configurable hysteresis is used to prevent the fan from changing speeds er- ratically. The default value is 0.5° F (shown above).

Also, the control will increase the fan speed as the Supply Air Temperature approaches the configured Minimum or Max- imum SAT limits.

Fan Speed Control (During Heating) — Whenever heat is re- quired and active, the control continuously monitors the sup- ply-air temperature to verify it does not rise above the config-

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