Carrier WSHP Open v3 Quick setup guide

W
WS SH HP P O Op pe en n v v3 3
I
In nt te eg gr ra at ti io on n G Gu ui id de e
CARRIER CORPORATION ©2012
A member of the United Technologies Corporation family · Stock symbol UTX · Catalog No. 11-808-500-01 · 11/29/2012

WSHP Open v3 i
Table of Contents
Introduction.................................................................................................................................................................. 1
What is the WSHP Open controller?..................................................................................................................1
Safety Considerations ..........................................................................................................................................3
Wiring inputs and outputs........................................................................................................................................... 4
Installation ................................................................................................................................................................... 5
Communications wiring - protocols ...................................................................................................................5
Protocol Overview.................................................................................................................................. 5
Configuring for BACnet MS/TP ............................................................................................................. 6
Configuring for Modbus RTU................................................................................................................. 7
Configuring for N2 ................................................................................................................................. 9
LonWorks .............................................................................................................................................10
Configuring for LonWorks Option Card (Part #LON-OC) .........................................................11
Commissioning the controller for LonWorks communication................................................12
Start-up ................................................................................................................................................12
Sequence of Operation .......................................................................................................................13
Scheduling ................................................................................................................................13
Fire/Smoke detector input ......................................................................................................14
Shutdown input ........................................................................................................................14
Indoor fan .................................................................................................................................14
Cooling ......................................................................................................................................15
Reverse cycle heating ..............................................................................................................16
Auxiliary heat ............................................................................................................................17
Indoor air quality (IAQ) and demand control ventilation (DCV) ..............................................18
Dehumidification ......................................................................................................................18
Waterside economizer .............................................................................................................19
Demand limiting .......................................................................................................................20
Power failure restart delay.......................................................................................................20
Alarms .......................................................................................................................................20
Troubleshooting .........................................................................................................................................................22
LED's .................................................................................................................................................................... 22
BACnet MS/TP ................................................................................................................................................... 23
Modbus................................................................................................................................................................ 25
Johnson N2 ......................................................................................................................................................... 25
LonWorks ............................................................................................................................................................ 26
Compliance ................................................................................................................................................................27
FCC Compliance................................................................................................................................................. 27
CE Compliance ................................................................................................................................................... 27
BACnet Compliance........................................................................................................................................... 27
Appendix A: Network Points List for WSHP Open ..................................................................................................28
Appendix B: BACnet Protocol Implementation Conformance Statement ...........................................................32
Appendix C: Modbus Protocol Implementation Conformance Statement...........................................................33
Appendix D: Johnson Controls N2 Protocol Implementation Conformance Statement.....................................35
Appendix E: LonWorks Protocol Implementation Conformance Statement .......................................................37
Index ...........................................................................................................................................................................38

WSHP Open v3 1
What is the WSHP Open controller?
The Water Source Heat Pump (WSHP) controller is available as an integrated component of a Carrier packaged
unit. Its internal application programming provides optimum performance and energy efficiency. WSHP Open
enables the unit to run in 100% stand-alone control mode or it can communicate to the Building Automation
System (BAS).
On board DIP switches allow you to select the baud rate and choose one of the following protocols:
•BACnet
•Modbus
•Johnson N2
•LonWorks
Carrier’s diagnostic display tools such as BACview®6Handheld device or Virtual BACview application can be used
with the WSHP Open controller via the 5-pin
J12
Access port. Refer to illustration below.
Introduction

Introduction
2 WSHP Open v3
CAUTION
If there is a jumper on the Format pins and power is cycled to the controller, all Modbus, N2, and
LonWorks points will be lost.

WSHP Open v3 3
Safety Considerations
Disconnect electrical power to the WSHP Open before wiring it. Failure to follow this warning could cause
electrical shock, personal injury, or damage to the controller.
When you handle the WSHP Open:
•Do not contaminate the printed circuit board with fingerprints, moisture, or any foreign material.
•Do not touch components or leads.
•Handle the board by its edges.
•Isolate from high voltage or electrostatic discharge.
•Ensure that you are properly grounded.

Wiring inputs and outputs
4 WSHP Open v3
WSHP Open Inputs and Outputs Table
Input/Output Type Part Numbers Type of I/O Connection Pin
Numbers
I/O Channel
Inputs
Space Temperature Sensor SPS, SPPL, SPP Communicating
J13
, 1 - 4 Local Access Port
Space Relative Humidity 33ZSENSRH-02
AI
(4-20 mA)
J4
- 5 & 6 AI - 1
Indoor Air Quality 33ZCSPTCO2
AI
(4-20 mA)
J4
- 2 & 3 AI - 2
Condensate Switch N/A
BI
(Dry Contacts)
J1
- 2 BI - 3
Stage 1 Compressor Status N/A
BI
(Dry Contacts)
J1
- 10 BI - 5
Leaving Condenser Water Temp 10K Type II
AI
(10K Thermistor)
J2
- 1 & 2 AI - 6
Supply Air Temperature 33ZCSENSAT
AI
(10K Thermistor)
J2
- 3 & 4 AI - 7
Supply Fan Status N/A
BI
(Dry Contacts)
J5
- 1 & 2 BI - 8
Occupancy Contact N/A
BI
(Dry Contacts)
J5
- 1 & 2 BI - 8
Smoke Detector Input** N/A 24 Vac
J1
- 9 24 Vac IN
Outputs
Aux Heat - Modulating (HW
Valve/Water Econ)
N/A
AO
(0-10 Vdc/
2-10 mA)
*
J2
- 4 & 5 AO - 1
Outside Air Damper N/A
AO
(0-10 Vdc/
2-10 mA)
*
J22
- 1 & 2 AO - 2
Supply Fan On/
Low speed (3-speed only)
N/A
BO
Relay (24 Vac, 3A) *
J1
- 4 BO - 1 (G)
W2-Aux Heat or 2-pos. Water
Economizer
N/A
BO
Relay (24 Vac, 3A) *
J1
- 5 BO - 2
Reversing Valve (B or O) N/A
BO
Relay (24 Vac, 3A) *
J1
- 6 BO - 3 (RV)
Y2-Compressor 2nd stage N/A
BO
Relay (24 Vac, 3A)
J1
- 7 BO - 4 (Y2)
Y1-Compressor 1st stage N/A
BO
Relay (24 Vac, 3A)
J1
- 8 BO - 5 (Y1)
Dehumidification Relay
N/A
BO
Relay (24 Vac, 3A)
*
J11
- 7 & 8 (N.O.)
BO - 6
Fan Speed Medium/Low
(3-speed Only)
N/A
BO
Relay (24 Vac, 3A) *
J11
- 5 & 6 (N.O.)
BO - 7
Fan Speed High/Low
(3-speed Only)
N/A
BO
Relay (24 Vac, 3A) *
J11
- 2 & 3 (N.O.) BO - 8
Legend
AI
-Analog Input
AO
- Analog Output
BI
-Digital Input
BO
- Digital Output
*These outputs are configurable.
**24 Vac required at this terminal to provide unit operation. Connect an isolated N.C. smoke detector contact (or jumper) between 24 Vac
and
J1
- 9.
Wiring inputs and outputs

WSHP Open v3 5
Communications wiring - protocols
Protocol Overview
Protocols are the communication languages spoken by the control devices. The main purpose of a protocol is to
communicate information in the most efficient method possible. Different protocols exist to provide specific
information for different applications.
In the BAS application, many different protocols are used, depending on manufacturer. Different protocols do not
change the function of the controller, but they typically require the owner to change systems or components in
order to change from one protocol to another. The WSHP Open is an effective solution to minimize the amount of
controllers that you may need to change in order to communicate with different types of protocols.
You can set the controller to communicate 1 of 4 different protocols:
•BACnet MS/TP
•Modbus
•N2
•LonWorks
The default setting is BACnet MS/TP. Switch 3 (
SW3
) on the board sets protocol and baud rate. Switches
MSB
(
SW1
) and
LSB
(
SW2
) set the board’s network address. See table below for specific switch settings. The third
party connects to the controller through port
J19
for BACnet MS/TP, Modbus, and N2, and through
J15
for the
LonWorks Option Card.
NOTES
•Changing protocol requires no programming or point assignment by the installer or operator.
•Power must be cycled after changing the
MSB
(
SW1
) -
LSB
(
SW2
) settings or connecting the LonWorks Option
Card to
J15
.
SW3 Switch Settings Table
Protocol Selection
Baud Rate
Protocol
DS8
DS7
DS6
DS5
DS4
DS3
DS2
DS1
BACnet MS/TP
(Default)
Master Unused Off Off Off On Off Select Baud Select Baud
Modbus
Slave Unused Off Off On On Off Select Baud Select Baud
N2
Slave Unused Off Off Off On On Off Off
Lonworks
Unused On On Off On Off Off On
Baud Selection Table
Baud Rate
SW3/DS2
SW3/DS1
9,600
Off Off
19,200
On Off
38,400
Off On
76,800
(Default) On On
Installation

Installation
6 WSHP Open v3
Configuring for BACnet MS/TP
Refer to Appendix B for the Protocol Implementation Conformance Statement, or download the latest from BACnet
International http://www.bacnetinternational.net/catalog/index.php?m=28.
1 Turn
off
the WSHP Open's power.
NOTE
Changes made to the switches when the controller is on will not take effect until the power is cycled!
2 Using the rotary switches
MSB
(
SW1
) and
LSB
(
SW2
), set a unique MS/TP MAC address for the WSHP Open.
Set the
MSB
(
SW1
) switch to the tens digit of the address, and set the
LSB
(
SW2
) switch to the ones digit.
Valid addresses are 01-99.
NOTE
The rotary switches also determine the BACnet device instance of the controller on the BACnet
network. The BACnet device instance is automatically generated based on the scheme 16101xx, where “16”
is the BACnet vendor ID for Carrier Corporation, and xx equals the rotary switch address.
EXAMPLE
To set the controller’s MS/TP MAC address to 01, point the arrow on the
MSB
(
SW1
) switch to 0
and the arrow on the
LSB
(
SW2
) switch to 1. Internally, the BACnet device instance is automatically
generated as 1610101.
3 Set the
SW3
Comm Selector DIP switches
DS1
and
DS2
for the appropriate communications speed (9600,
19.2k, 38.4k, or 76.8k bps).
NOTE
Use the same baud rate and communication settings for all controllers on the network segment. The
WSHP Open is fixed at 8 data bits, No Parity, and 1 Stop bit for this protocol's communications.
Baud Selection Table
Baud Rate
SW3/DS2
SW3/DS1
9,600
Off Off
19,200
On Off
38,400
Off On
76,800
On On
4 Set
SW3
Comm Selector DIP switches
DS3
through
DS6
for BACnet MS/TP. See table and example below.
5 Leave
DS7
and
DS8
in the OFF position. These switches are not applicable to MS/TP.
SW3 Protocol Switch Settings for MS/TP
DS8
DS7
DS6
DS5
DS4
DS3
Off Off Off Off On Off

WSHP Open v3 7
The following example shows the DIP switches set for 76.8k (Carrier default), and MS/TP.
6 Connect the MS/TP network to the controller's
J19
port. Connect to
Net+
,
Net-
, and
SHLD
.
Wire specifications
○A dedicated 22 AWG shielded twisted pair wire (EIA 485)
○Maximum wire length 2000 feet (610 meters) or 32 nodes
○Devices should be daisy-chained and not star-wired
○Attach the drain/shield wire to both ends of the network segment and through every controller
NOTE
Use the same polarity throughout the network segment.
7 Turn
on
the WSHP Open's power.
Configuring for Modbus RTU
Refer to Appendix C (page 33) for the Modbus Protocol Implementation Conformance Statement (PICS).
1 Turn
off
the WSHP Open's power.
NOTE
Changes made to the switches when the controller is on will not take effect until the power is cycled!
2 Using the rotary switches, set a unique Modbus slave address for the WSHP Open. Set the
MSB
(
SW1
) switch
to the tens digit of the address, and set the
LSB
(
SW2
) switch to the ones digit. Valid Modbus slave
addresses are 01-99.
EXAMPLE
To set the controller's Modbus slave address to 01, point the arrow on the
MSB
(
SW1
) switch to 0
and the arrow on the
LSB
(
SW2
) switch to 1.

Installation
8 WSHP Open v3
3 Set the
SW3
Comm Selector DIP switches
DS1
and
DS2
for the appropriate communications speed (9600,
19.2k, 38.4k, or 76.8k bps).
NOTE
Use the same baud rate and communication settings for all controllers on the network segment. The
WSHP Open is fixed at 8 data bits, No Parity, and 1 Stop bit for this protocol's communications.
Baud Selection Table
Baud Rate
SW3/DS2
SW3/DS1
9,600
Off Off
19,200
On Off
38,400
Off On
76,800
On On
4 Set
SW3
Comm Selector DIP switches
DS3
through
DS6
for Modbus. See example below.
5 Leave
DS7
and
DS8
in the OFF position. These switches are not applicable to Modbus.
SW3 Protocol Switch Settings for Modbus
DS8
DS7
DS6
DS5
DS4
DS3
Off Off Off On On Off
The following example shows the DIP switches set for 9600 baud and Modbus.
6 Connect the Modbus EIA-485 network to the WSHP Open's
J19
port. Connect to
Net+
,
Net-
, and
SHLD
.
Wire specifications
○A dedicated 22 AWG shielded twisted pair wire (EIA 485)
○Maximum wire length 2000 feet (610 meters) or 32 nodes
○Devices should be daisy-chained and not star-wired
○Attach the drain/shield wire to both ends of the network segment and through every controller
NOTE
Use the same polarity throughout the network segment.
7 Turn
on
the WSHP Open's power.

WSHP Open v3 9
Configuring for N2
Refer to Appendix D (page 35) for the N2 Protocol Implementation Conformance Statement (PICS).
1 Turn
off
the WSHP Open's power.
NOTE
Changes made to the switches when the controller is on will not take effect until the power is cycled!
2 Using the rotary switches, set a unique N2 slave address for the WSHP Open. Set the
MSB
(
SW1
) switch to
the tens digit of the address, and set the
LSB
(
SW2
) switch to the ones digit. Valid N2 slave addresses are
01-99.
EXAMPLE
To set the N2 slave address to 01, point the arrow on the
MSB
(
SW1
) switch to 0 and the arrow on
the
LSB
(
SW1
) switch to 1.
3 Set the Comm Selector DIP switches
DS1
and
DS2
for the 9600 baud.
NOTE
Use the same baud rate and communication settings for all controllers on the network segment.
TheWSHP Open is fixed at 9600 baud, 8 data bits, No Parity, and 1 Stop bit.
4 Set
SW3
Comm Selector DIP switches
DS3
through
DS6
for N2. See example below.
5 Leave
DS7
and
DS8
in the OFF position. These switches are not applicable to N2.
SW3 Protocol Switch Settings for N2
DS8
DS7
DS6
DS5
DS4
DS3
Off Off Off Off On On
The following example shows the DIP switches set for 9600 baud and N2.
6 Connect the N2 EIA-485 network to the controller's
J19
port. Connect to
Net+
,
Net-
, and
SHLD
.

Installation
10 WSHP Open v3
Wire specifications
○A dedicated 22 AWG shielded twisted pair wire (EIA 485)
○Maximum wire length 2000 feet (610 meters) or 32 nodes
○Devices should be daisy-chained and not star-wired
○Attach the drain/shield wire to both ends of the network segment and through every controller
NOTE
Use the same polarity throughout the network segment.
7 Turn
on
the WSHP Open's power.
LonWorks
When you handle the LonWorks Option Card:
•Do not contaminate the printed circuit board with fingerprints, moisture, or any foreign material.
•Do not touch components or leads.
•Handle the board by its edges.
•Isolate from high voltage or electrostatic discharge.
•Ensure that you are properly grounded.
Refer to Appendix E for the LonWorks Protocol Implementation Conformance Statement (PICS).

WSHP Open v3 11
Configuring for LonWorks Option Card (Part #LON-OC)
1 Turn
off
the WSHP Open's power.
NOTES
○Changes made to the switches when the controller is on will not take effect until the power has been
cycled!
○The controller’s rotary address switches are not used when the LON-OC is installed. That’s because each
LON-OC has a 48-bit Neuron ID that makes it unique on the LonWorks network.
2 Set the Comm Selector DIP switches
DS1
and
DS2
on
SW3
for 38.4k Communications speed. This is the
speed at which the LON-OC speaks to the WSHP Open. It is fixed at 38.4k.
3 Set the Comm Selector DIP switches
DS3
through
DS6
on
SW3
for LonWorks. See example below.
4 Set the Comm Selector DIP switch
DS7
on
SW3
to the ON position to enable the LON-OC.
5 Leave Comm Selector DIP switch
DS8
on
SW3
in the OFF position since it is not used.
SW3 Protocol Switch Settings for LonWorks
DS8
DS7
DS6
DS5
DS4
DS3
Off On On Off On Off
The following example shows the DIP switches set for 38.4k baud and the LON-OC enabled.
6 Plug the LON-OC's ribbon cable into Comm Option Port
J15
on the controller. See illustration below.
CAUTION!
The controller must be
OFF
before being connected.

Installation
12 WSHP Open v3
7 Connect the LonWorks network to the LON-OC via the 2-pin
Net
port.
NOTE
The 2-pin
Net
port provides TP/FT-10 channel compatibility. The TP/FT-10 or "Free Topology" network
type is
polarity insensitive
. Use 24 to 16 AWG twisted pair wire.
8 Turn
on
the WSHP Open's power.
9 Commission the controller for LonWorks communication. See instructions below.
Commissioning the controller for LonWorks communication
Before a device can communicate on a LonWorks network, it must be commissioned. Commissioning allows the
system integrator to associate the device hardware with the LonWorks system’s network layout diagram. This is
done using the device’s unique Neuron ID.
A network management tool such as Echelon’s LonMaker is used to commission each device, as well as to assign
addressing. Specific instructions regarding the commissioning of LonWorks devices should be obtained from
documentation supplied with the LonWorks Network Management Tool.
When a new device is first commissioned onto the LonWorks network, the system integrator must upload the
device’s External Interface File (XIF) information. LonWorks uses the XIF to determine the points (network
variables) that are available from a device. The WSHP Open has a set of predefined network variables. These
variables can be bound or accessed by the network management tool.
NOTE
Contact your local Carrier representative for a copy of the .XIF file.
The
Browse
feature of the Network Management Tool allows you to read real-time values from the WSHP Open.
The Network Management Tool allows you to test integration prior to binding the controller's network variables to
other LonWorks nodes.
Start-up
To start up the WSHP Open, you need one of the following user interfaces to the controller. These items let you
access the controller information, read sensor values, and test the controller.
This interface...
Provides a...
Virtual BACview
application -
runs on a laptop connected to controller's Local Access port 1, 2
Temporary interface
BACview6 Handheld
keypad/display device -
connects to controller's Local Access port 1, 2
Temporary interface
BACview6
keypad/display device
connected to controller's Rnet port 2
Permanent interface
1Requires a USB Link (USB-L).
2See the BACview Installation and User Guide for instructions on connecting and using the above items.

WSHP Open v3 13
Sequence of Operation
The multi-protocol WSHP Open controls mechanical cooling, heating, and waterside economizer outputs, based on
its own space temperature input and setpoints. An optional CO2 IAQ (Indoor Air Quality) sensor that is mounted in
the space maximizes the occupant's comfort. The WSHP Open has its own hardware clock that is automatically set
when you download the heat pump software to the board.
See Scheduling (page 13) for occupancy types.
The following sections describe the multi-protocol controller's functions. All point objects mentioned in this
sequence of operation reference the BACview6Handheld interface. Points in Field Assistant and the i-Vu®
application are the same or similar.
Scheduling
Scheduling
- You must configure time periods to schedule the transitions from occupied to unoccupied operation.
The time periods control the space temperature to occupied heating and cooling setpoints. The WSHP Open
operates continuously in the
Occupied
mode until you configure either a time schedule or a third party control
system
Enables/Disables
the
BAS On/Off
point. You must set your local time and date for these functions to
operate properly.
You can change the occupancy source to one of the following:
Occupancy Schedules
- The controller is occupied 24/7 until you configure a time schedule using either the
BACview6 device, Field Assistant, the i-Vu application, or a third party
Enables/Disables
the
BAS On/Off
point. You
can disable this by going to
Configuration
>
Unit Configuration
>
Occupancy Schedules
, changing the point from
Enable
to
Disable
and clicking
OK
.
NOTE
You must
Enable
this point in order for the BACview6 device, Field Assistant, or the i-Vu application to assign
a time schedule to the controller.
Schedule_Schedule
- The unit operates according to the schedule configured and stored in the unit. The schedule
is accessible via the BACview6Handheld device, the i-Vu application, or Field Assistant. The daily schedule
consists of a start and stop time (standard or 24-hour mode) and 7 days of the week, starting with Monday and
ending on Sunday. To enter a daily schedule, navigate to
Configuration
>
Schedule
, enter BACview6Admin
Password (1111) >
schedule_schedule
and then enter either a
Weekly
or
Exception
schedule for the unit.

Installation
14 WSHP Open v3
Important note for the following:
Scheduling can only be controlled from one source.
Occupancy Input Contact (Option)
- If configured for remote occupancy control (default), the WSHP Open can use
an external dry contact closure to determine the occupancy status of the unit. You must disable the
Occupancy
Schedules
in order to utilize the occupancy contact input. The unit enters an occupied mode whenever it senses
the abnormal input. After the input returns to its normal state, the unit stays in the occupied mode for the
configured
Occ Override Delay
period (15 minutes default).
BAS (Building Automation System) On/Off
- For use with a Building Automation System that supports network
scheduling, you must disable the
Occupancy Schedules
so the BAS system can control the unit through a network
communication and the BAS scheduling function.
Global Occupancy Scheduling
- The WSHP Open can read the occupancy status from another unit so that a group
of WSHP's can be controlled from a single occupancy schedule. The local
Occupancy Schedules
must be disabled
in order to utilize the global occupancy input.
BACnet Network Occupancy Input
- The WSHP Open can accept an external BACnet Binary Network Input for
occupancy control. This function is only compatible with units used in BACnet systems. You need to configure the
System Occupancy BACnet network input point to locate the device and point name where the external occupancy
point information resides. You must also disable
Occupancy Schedules
in order to utilize this input.
Fire/Smoke detector input
The WSHP Open can read the status of a normally closed FSD contact input to determine if a fire or smoke
detector alarm is present. If the controller determines an alarm condition is present, all heating, cooling, and the
fan are disabled. The switch is factory-set to
Normally Closed
and cannot be changed.
Shutdown input
The WSHP Open controller has a shutdown input (software point) which, when set to its
Active
mode causes the
WSHP to safely shutdown in a controlled fashion. Heating and cooling is disabled after any minimum runtime
conditions expire and the fan is disabled after the fan-off timer expires. All alarms are reset but any active alarm
remains active. After the shutdown input transitions from
Active
mode to
Inactive
, the WSHP Open restarts after
the configured power fail restart delay expires.
Indoor fan
You can configure the indoor fan to operate in any one of 3
Fan Modes
:
•
Auto
- intermittent operation during both occupied and unoccupied periods
•
Continuous
(default) - intermittent operation during unoccupied periods and continuous during occupied
periods
•
Always on
- operates the fan continuously during both occupied and unoccupied periods
In the
Continuous
default mode, the fan is turned on whenever any one of the following is true:
•It is in occupied mode, which is determined by the occupancy status
•There is a demand for cooling or heating in the unoccupied mode
•There is a call for dehumidification (optional)

WSHP Open v3 15
When power is reapplied after a power outage, there is a configurable delay of 5 - 600 seconds (default 60)
before starting the fan. You must configure the fan delay:
•The
Fan On Delay
defines the delay time (0 - 30 seconds, default 10) before the fan begins to operate after
heating or cooling is started.
•The
Fan Off Delay
defines the delay time (0 - 180 seconds, default 45) the fan continues to operate after
heating or cooling is stopped.
NOTE
The fan continues to run as long as the compressors, heating stages, or the dehumidification relays are on.
If the SPT failure alarm or condensate overflow alarm is active, the fan is shutdown immediately, regardless of
occupancy state or demand.
Automatic Fan Speed Control
- The WSHP Open can control up to 3 fan speeds using the ECM (Electronically
Commutated Motor). The motor operates at the lowest speed possible to provide quiet and efficient fan operation
with the best latent capability. The motor increases speed if additional cooling or heating is required to reach the
desired space temperature setpoint. The control increases the motor’s speed as the space temperature rises
above the cooling or below the heating setpoint. The amount of space temperature increase above or below the
setpoint required to increase the fan speed is configurable in the setpoint. Also, the control increases the fan
speed as the
Supply Air Temperature
approaches the configured minimum or maximum limits.
Fan Speed Control
•
During heating
– Whenever heat is required and active, the control continuously monitors the supply air
temperature to verify it does not rise above the configured
Maximum Heating SAT Limit
(110° default). As
the SAT approaches this value, the control increases the fan speed as required to ensure the SAT remains
within the limit. This provides the most quiet and efficient operation by running the fan at the lowest speed
possible.
•
During cooling
– Whenever mechanical cooling is required and active, the control continuously monitors the
supply air temperature to verify it does not fall below the configured
Minimum Cooling SAT Limit
(50°
default). As the SAT approaches this value, the control increases the fan speed as required to ensure the SAT
will remain within the limit. Fan operates at the lowest speed during dehumidification to maximize latent
capacity during cooling.
Fan Status
- You can configure an optional input as either an occupancy input contact or a fan status input. If
configured as fan status, the controller compares the status of the fan to the desired commanded state.
Whenever the fan is commanded to run (ON), the fan status is checked and verified to match the commanded
state. If the fan status is not on, then a fan status alarm is generated after 1 minute and the equipment’s
compressor(s) and auxiliary heat is disabled and the optional OA damper closes.
Cooling
The WSHP Open operates 1 or 2 stages of compression to maintain the desired cooling setpoint. The compressor
outputs are controlled by the PI (Proportional-integral) cooling loop and cooling stages capacity algorithm. The
algorithm calculates the desired number of stages needed to satisfy the space by comparing the space
temperature (SPT) to the appropriate cooling setpoint.
NOTE
The waterside economizer, if applicable, is used for 1st stage cooling, in addition to the compressor(s).
The following conditions must be true for the cooling algorithm to run:
•
Cooling
is set to
Enable
•The
Fire/Smoke Input
and
Shutdown
modes are inactive
•
Heat
mode is not active and the compressor time guard(s) have expired
•
Condensate Overflow
input in
Normal
•
Fan Status
is
True
(if option is enabled)
•If occupied, the SPT is greater than the occupied cooling setpoint

Installation
16 WSHP Open v3
•Space temperature reading is valid
•If unoccupied, the SPT is greater then the unoccupied cooling setpoint
•If economizer cooling is available and active, and the economizer alone is insufficient to provide enough
cooling
•OAT >
Cooling Lockout Temperature
if OAT is available
•
Condenser Water Pump
is on (if
Condensor Water Linkage
active)
If all of the above conditions are met, the compressors' relays are energized as required. Otherwise, they will be
de-energized. If cooling is active and if the SAT approaches the minimum SAT limit, the fan will be indexed to the
next higher speed. If this is insufficient, and if the SAT falls further (equal to the minimum SAT limit), the fan will be
indexed to the maximum speed. If the SAT still continues to falls 5° F below the minimum SAT limit, all cooling
stages will be disabled.
During
Cooling
, the reversing valve output is held in the cooling position (either B or O type, as configured), even
after the compressor is stopped. The valve does not switch position until the heating mode is required.
The configuration screens contain the
Min SAT
parameter as well as
Cooling Lockout
based on outdoor air
temperature (OAT). Both can be adjusted to meet various specifications.
There is a 5-minute off-time for the compressor, as well as a 5-minute time delay, when staging up to allow the
SAT to achieve a stable temperature, before energizing a second stage of capacity. Likewise, there is a 45-second
delay when staging down.
After a compressor is staged off, it may be restarted again after a normal time-guard period of 5 minutes and if
the supply air temperature has increased above the minimum supply air temperature limit.
The WSHP Open provides a status input to monitor the compressor operation. The status is monitored to
determine if the compressor status matches the commanded state. This input is used to determine if a refrigerant
safety switch or other safety device has tripped and caused the compressor to stop operating normally. If this
occurs, an alarm is generated to indicate the faulted compressor condition.
Reverse cycle heating
The WSHP Open operates 1 or 2 stages of compression to maintain the desired cooling setpoint. The compressor
outputs are controlled by the heating PI (Proportional-integral) loop and heating stages capacity algorithm. The
algorithm calculates the desired number of stages needed to satisfy the space by comparing the space
temperature (SPT) to the appropriate heating setpoint.
The following conditions must be true for the heating algorithm to run:
•
Heating
is set to
Enable
•The
Fire/Smoke Input
and
Shutdown
modes are inactive
•
Cool
mode is not active and the compressor time guard has expired
•
Condensate Overflow
input in
Normal
•
Fan Status
is
True
(if option is enabled)
•If occupied, the SPT is less than the occupied heating setpoint
•
Space Temperature
reading is valid
•If unoccupied, the SPT is less then the unoccupied heating setpoint
•
OAT
>
Heating Lockout Temperature
if OAT is available
•
Condenser Water Pump
is on (if
Condensor Water Linkage
active)