York VERSECON YSWU Series Troubleshooting guide

QUICK START-UP GUIDE
VERSECON
AIR CONDITIONING UNITS
New Release Form 145.05-SU2 (1207)
VERSECON™
Indoor Upow Self-Contained Air Conditioner
YSWU 10–105 Ton Water-Cooled
Indoor Downow Self Contained Air Conditioner
YSWD 10–105 Ton Water-Cooled
035-22105-000

JOHNSON CONTROLS
2
FORM 145.05-SU2 (1207)
This equipment is a relatively complicated apparatus.
During installation, operation, maintenance or service,
individuals may be exposed to certain components or
conditions including, but not limited to: refrigerants,
oils, materials under pressure, rotating components,
and both high and low voltage. Each of these items
has the potential, if misused or handled improperly, to
cause bodily injury or death. It is the obligation and
responsibility of operating/service personnel to identify
and recognize these inherent hazards, protect themselves,
and proceed safely in completing their tasks. Failure to
comply with any of these requirements could result in
serious damage to the equipment and the property in
IMPORTANT!
READ BEFORE PROCEEDING!
GENERAL SAFETY GUIDELINES
which it is situated, as well as severe personal injury or
death to themselves and people at the site.
This document is intended for use by owner-authorized
operating/service personnel. It is expected that this
individual possesses independent training that will
enable them to perform their assigned tasks properly
and safely. It is essential that, prior to performing any
task on this equipment, this individual will have read
and understood this document and any referenced
materials. This individual will also be familiar with and
comply with all applicable governmental standards and
regulations pertaining to the task in question.
SAFETY SYMBOLS
The following symbols are used in this document to alert the reader to areas of potential hazard:
CAUTION identies a hazard which
could lead to damage to the machine,
damage to other equipment and/or
environmental pollution. Usually an
instruction will be given, together with
a brief explanation.
NOTE is used to highlight additional
information which may be helpful to
you.
DANGER indicates an imminently
hazardous situation which, if not
avoided, will result in death or serious
injury.
WARNING indicates a potentially
hazardous situation which, if not
avoided, could result in death or se-
rious injury.
External wiring, unless specied as an optional connection in the manufacturer’s product
line, is not to be connected inside the control panel cabinet. Devices such as relays, switches,
transducers and controls may not be installed inside the control panel. No external wir-
ing is allowed to be run through the control panel. All wiring must be in accordance with
YORK’s published specications and must be performed only by qualied YORK personnel.
YORK will not be responsible for damages/problems resulting from improper connections
to the controls or application of improper control signals. Failure to follow this will void the
manufacturer’s warranty and cause serious damage to property or injury to persons.

3
JOHNSON CONTROLS
FORM 145.05-SU2 (1207)
CHANGEABILITY OF THIS DOCUMENT
In complying with YORK’s policy for continuous product improvement, the information contained in this document
is subject to change without notice. While YORK makes no commitment to update or provide current information
automatically to the manual owner, that information, if applicable, can be obtained by contacting the nearest YORK
Applied Systems Service ofce.
It is the responsibility of operating/service personnel to verify the applicability of these documents to the equipment
in question. If there is any question in the mind of operating/service personnel as to the applicability of these
documents, then prior to working on the equipment, they should verify with the owner whether the equipment has
been modied and if current literature is available.
NOMENCLATURE
YSWU039 - YORK Versecon Water Cooled, Upow, 39 Nominal Tons
YSWU - YORK Floor x Floor, Water Cooled, Upow
YSWD - YORK Floor x Floor, Water Cooled, Downow

JOHNSON CONTROLS
4
FORM 145.05-SU2 (1207)
TABLE OF CONTENTS
GENERAL SAFETY GUIDELINES ......................................................................................................................2
SAFETY SYMBOLS.............................................................................................................................................2
CHANGEABILITY OF THIS DOCUMENT ...........................................................................................................3
NOMENCLATURE ...............................................................................................................................................3
QUICK START GUIDE – VERSECON - WATER COOLED ................................................................................5
ALL UNITS...........................................................................................................................................................6
ON / OFF – MANUAL SWITCH.....................................................................................................................6
ON / OFF – INTERNAL CLOCK....................................................................................................................6
ON / OFF – COMMUNICATED......................................................................................................................6
CONDENSER WATER VALVE MINIMUM POSITION ..................................................................................6
COMMUNICATED VFD FAN SPEED CONTROL .........................................................................................6
CONSTANT VOLUME ........................................................................................................................................7
COOLING SUPPLY AIR TEMPERATURE CONTROL .................................................................................7
COOLING RETURN AIR TEMPERATURE CONTROL ................................................................................7
COOLING SUPPLY AIR AND RETURN AIR TEMPERATURE CONTROL..................................................7
SUPPLY FAN OPERATION...........................................................................................................................7
VARIABLE AIR VOLUME ...................................................................................................................................8
COOLING SUPPLY AIR TEMPERATURE CONTROL .................................................................................8
COOLING RETURN AIR TEMPERATURE CONTROL ................................................................................8
COOLING SUPPLY AIR AND RETURN AIR TEMPERATURE CONTROL..................................................8
SUPPLY FAN OPERATION...........................................................................................................................9
SUPPLY FAN DUCT STATIC PRESSURE....................................................................................................9
FLEXSYS ...........................................................................................................................................................10
COOLING SUPPLY AIR TEMPERATURE CONTROL ...............................................................................10
COOLING RETURN AIR TEMPERATURE CONTROL ..............................................................................10
COOLING SUPPLY AIR AND RETURN AIR TEMPERATURE CONTROL................................................10
SUPPLY FAN OPERATION.........................................................................................................................10
SUPPLY FAN DUCT STATIC PRESSURE.................................................................................................. 11
SUPPLY AIR PROVING SET POINT .......................................................................................................... 11
MINIMUM COIL PRESSURE DROP ........................................................................................................... 11
FLEXSYS DEW POINT TEMPERATURE CONTROL.......................................................................................12
WATER SIDE ECONOMIZER ............................................................................................................................13
CONDENSER WATER BYPASS .......................................................................................................................13
AIR SIDE ECONOMIZER...................................................................................................................................14
HEATING OPERATION - STAGED....................................................................................................................15
HEATING SUPPLY AIR TEMPERATURE CONTROL ................................................................................15
HEATING RETURN AIR TEMPERATURE CONTROL ...............................................................................15
HEATING SUPPLY AIR AND RETURN AIR TEMPERATURE CONTROL ................................................15
HEATING OPERATION - TRISTATE MODULATED .........................................................................................16
HEATING SUPPLY AIR TEMPERATURE CONTROL ................................................................................16
HEATING RETURN AIR TEMPERATURE CONTROL ...............................................................................16
HEATING SUPPLY AIR AND RETURN AIR TEMPERATURE CONTROL ................................................16

5
JOHNSON CONTROLS
FORM 145.05-SU2 (1207)
This Quick-Start Guide indicates required eld wiring
and minimum programming to provide proper unit
operation. This guide does not include required basic
installation practices discussed in the Installation,
Operation, and Maintenance manual, Form 145.05-
NOM1. The IOM should be reviewed to ensure all
proper procedures and safety precautions are followed
when installing the equipment.
In addition, any system alarms indicated by the User
Interface should be diagnosed as referenced in the
Installation, Operation, and Maintenance manual
– refer to Faults and Alarms in the Service section of
the manual.
QUICK START GUIDE – VERSECON - WATER COOLED
This Quick-Start Guide is indexed according to unit
type and options. Units are categorized as either
Constant Volume, Variable Air Volume, or FlexSys.
Refer to the applicable section for the required wiring
and programming.
References to “Programming” indicates the setpoints
that should be programmed/verified, under the
“Setpoints” section of the User Interface.
Unit options should be programmed based on the unit
conguration ordered from the factory.

JOHNSON CONTROLS
6
FORM 145.05-SU2 (1207)
ALL UNITS
ON / OFF – MANUAL SWITCH
To turn the unit ON turn the ON/AUTO/OFF toggle
switch, located below the User Interface, from the OFF
to ON position.
Field Wiring
None required.
Programming
None required.
ON / OFF – INTERNAL CLOCK
To turn the unit ON, turn the ON/AUTO/OFF toggle
switch (located below the User Interface) from the OFF
to AUTO position. The unit will then be switched to
ON based on the ON/OFF schedule programmed in the
User Interface.
Field Wiring
None required.
Programming
Go to the “Daily Sched” section of the User Interface.
Change the “Daily Schedule Status” to ON. Program
the “Start” and “Stop” times for each day of the
week.
ON / OFF – COMMUNICATED
To turn the unit ON, turn the ON/AUTO/OFF toggle
switch (located below the User Interface) from the OFF
to AUTO position. The unit will then be switched to
ON based on a communicated input from the BAS
system.
Field Wiring
Connect the (+) wire of a shielded twisted pair to the
(+) terminal of the Network Port. Connect the (-) wire
of a shielded twisted pair to the (-) terminal of the
Network Port.
Programming
Go to the “Daily Sched” section of the User Interface.
Change the “Daily Schedule Status” to OFF.
CONDENSER WATER VALVE MINIMUM POSITION
This parameter establishes the minimum position of
the condenser water valve any time the unit is in the
ON mode.
Field Wiring
None required.
Programming
The following item must be programmed through the
“Setpoints” section of the User Interface:
•“ Cond Valve Min” – This parameter can be
set between 0 and 100%. The default value is
15%.
COMMUNICATED VFD FAN SPEED CONTROL
This feature can be ordered from the factory for units
that will be twinned together and share a common
supply duct. The feature allows a front end BAS system
to monitor the VFD fan speed of the lead unit and
communicate a VFD fan speed to the second unit.
Field Wiring
Connect the (+) wire of a shielded twisted pair to the
(+) terminal of the Network Port. Connect the (-) wire
of a shielded twisted pair to the (-) terminal of the
Network Port.
Programming
The following item must be programmed through the
“Setpoints” section of the User Interface:
• “Fan Sp BAS En” – To use this feature this pa-
rameter must be set to ON.

7
JOHNSON CONTROLS
FORM 145.05-SU2 (1207)
CONSTANT VOLUME
COOLING SUPPLY AIR TEMPERATURE CONTROL
This feature allows the unit to control the staging of
the compressors based on the difference between the
supply air temperature and the supply air temperature
set point.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “AC-S/A Temp En” must be set to ON. The de-
fault is ON
• “AC/Econ-S/A SP” set point must be pro-
grammed. The default value is 55.0˚ F. This
is the supply air temperature the unit will try to
maintain.
COOLING RETURN AIR TEMPERATURE
CONTROL
This feature allows the unit to control the staging of
the compressors based on the difference between the
return air temperature and the return air temperature
set point.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “AC-R/A Temp En” must be set to ON. The
default is OFF
• “AC/Econ-R/A SP” set point must be pro-
grammed. The default value is 75.0˚ F. This
is the return air temperature the unit will try to
maintain.
COOLING SUPPLY AIR AND RETURN AIR
TEMPERATURE CONTROL
This feature allows the unit to control the staging of the
compressor based on either the temperature difference
between the supply air temperature and the supply air
temperature set point and the return air temperature
and the return air temperature set point. When both are
selected the compressors will be cycled based on the
lesser of the two demands.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “AC-S/A Temp En” must be set to ON. The
default is ON.
• “AC/Econ-S/A SP” set point must be pro-
grammed. The default value is 55.0˚ F. This
is the supply air temperature the unit will try to
maintain.
• “AC-R/A Temp En” must be set to ON. The
default is OFF.
• “AC/Econ-R/A SP” set point must be pro-
grammed. The default value is 75.0˚ F. This
is the return air temperature the unit will try to
maintain.
SUPPLY FAN OPERATION
This feature tells the unit if is has a constant volume or
variable volume supply fan.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “Fan-VAV/CV En” must be set to CV. The de-
fault is VAV.

JOHNSON CONTROLS
8
FORM 145.05-SU2 (1207)
COOLING SUPPLY AIR TEMPERATURE CONTROL
This feature allows the unit to control the staging of
the compressors based on the difference between the
supply air temperature and the supply air temperature
set point.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “AC-S/A Temp En” must be set to ON. The
default is ON.
• “AC/Econ-S/A SP” set point must be pro-
grammed. The default value is 55.0˚ F. This
is the supply air temperature the unit will try to
maintain.
COOLING RETURN AIR TEMPERATURE
CONTROL
This feature allows the unit to control the staging of
the compressors based on the difference between the
return air temperature and the return air temperature
set point.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “AC-R/A Temp En” must be set to ON. The
default is OFF.
• “AC/Econ-R/A SP” set point must be pro-
grammed. The default value is 75.0˚ F. This
is the return air temperature the unit will try to
maintain.
COOLING SUPPLY AIR AND RETURN AIR
TEMPERATURE CONTROL
This feature allows the unit to control the staging of the
compressor based on either the temperature difference
between the supply air temperature and the supply air
temperature set point and the return air temperature
and the return air temperature set point. When both are
selected the compressors will be cycled based on the
lesser of the two differences.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “AC-S/A Temp En” must be set to ON. Default
is ON.
• “AC/Econ-S/A SP” set point must be pro-
grammed. The default value is 55.0˚ F. This
is the supply air temperature the unit will try to
maintain.
• “AC-R/A Temp En” must be set to ON. Default
is OFF.
• “AC/Econ-R/A SP” set point must be pro-
grammed. The default value is 75.0˚ F. This
is the return air temperature the unit will try to
maintain.
VARIABLE AIR VOLUME

9
JOHNSON CONTROLS
FORM 145.05-SU2 (1207)
SUPPLY FAN OPERATION
This feature tells the unit if is has a constant volume or
variable volume supply fan.
Field Wiring
None required.
Programming
The following item must be programmed through the
“Setpoints” section of the User Interface:
• “Fan-VAV/CV En” - must be set to VAV. The
default is VAV.
SUPPLY FAN DUCT STATIC PRESSURE
This feature allows the setting of the duct static control
point.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “Fan-S/A Pres SP” – must be set to the duct static
value you want to maintain. The range is 0.0”
WC to 2.0” WC. The default value is 1.0” WC
• “# of SP Sensors” – The control has the capability
to use one or two duct static sensors. If a single
sensor is used this value would be set to 1. If two
sensors are used this value would be set to 2.
• “SP Calc Method” – If the unit uses two sensors
this value can be set to “High, Avg, or Low”. If
the control is programmed to “High”, the con-
trol will compare the higher of the two sensor
inputs to the “Fan- S/A Pres SP” and control
the speed of the VFD based on these values. If
the control is programmed to “Low” the control
will compare the lower of the two sensor inputs
to the “Fan- S/A Pres SP” and control the speed
of the VFD based on these values. If the control
is programmed to “Avg” the control will compare
the average of the two sensors to the “Fan- S/A
Pres SP” and control the speed of the VFD based
on these values.
VARIABLE AIR VOLUME (continued)

JOHNSON CONTROLS
10
FORM 145.05-SU2 (1207)
COOLING SUPPLY AIR TEMPERATURE CONTROL
This feature allows the unit to control the staging of
the compressors based on the difference between the
supply air temperature and the supply air temperature
set point.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “AC-S/A Temp En” must be set to ON. Default
is ON.
• “AC/Econ-S/A SP” set point must be pro-
grammed. The default value is 55.0˚ F. This
is the supply air temperature the unit will try to
maintain.
COOLING RETURN AIR TEMPERATURE
CONTROL
This feature allows the unit to control the staging of
the compressors based on the difference between the
return air temperature and the return air temperature
set point.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “AC-R/A Temp En” must be set to ON. Default
is OFF.
• “AC/Econ-R/A SP” set point must be pro-
grammed. The default value is 75.0˚ F. This
is the return air temperature the unit will try to
maintain.
COOLING SUPPLY AIR AND RETURN AIR
TEMPERATURE CONTROL
This feature allows the unit to control the staging of the
compressor based on either the temperature difference
between the supply air temperature and the supply air
temperature set point and the return air temperature
and the return air temperature set point. When both are
selected the compressors will be cycled based on the
lesser of the two differences.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “AC-S/A Temp En” must be set to ON. Default
is ON.
• “AC/Econ-S/A SP” set point must be pro-
grammed. The default value is 55.0˚ F. This
is the supply air temperature the unit will try to
maintain.
• “AC-R/A Temp En” must be set to ON. Default
is OFF.
• “AC/Econ-R/A SP” set point must be pro-
grammed. The default value is 75.0˚ F. This
is the return air temperature the unit will try to
maintain.
SUPPLY FAN OPERATION
This feature tells the unit if is has a constant volume or
variable volume supply fan.
Field Wiring
None required.
Programming
The following item must be programmed through the
“Setpoints” section of the User Interface:
• “Fan-VAV/CV En” must be set to VAV. The
default is VAV.
FLEXSYS

11
JOHNSON CONTROLS
FORM 145.05-SU2 (1207)
SUPPLY FAN DUCT STATIC PRESSURE
This feature allows the setting of the duct static control
point.
Field Wiring
None required.
Programming
The following item must be programmed through the
“Setpoints” section of the User Interface:
• “Fan-S/A Pres SP” – must be set to the duct
static value you want to maintain. The range is
0.0” WC to 2.0” WC. The default value is 0.5”
WC.
• “# of SP Sensors” – The control has the capability
to use one or two duct static sensors. If a single
sensor is used this value would be set to 1. If two
sensors are used this value would be set to 2.
• “SP Calc Method” – If the unit uses two sensors
this value can be set to “High, Avg, or Low”. If
the control is programmed to “High”, the con-
trol will compare the higher of the two sensor
inputs to the “Fan- S/A Pres SP” and control
the speed of the VFD based on these values. If
the control is programmed to “Low” the control
will compare the lower of the two sensor inputs
to the “Fan- S/A Pres SP” and control the speed
of the VFD based on these values. If the control
is programmed to “Avg” the control will compare
the average of the two sensors to the “Fan- S/A
Pres SP” and control the speed of the VFD based
on these values.
SUPPLY AIR PROVING SET POINT
The Unit Control monitors the pressure drop across
the evaporator coil to determine if the supply fan is
operating. If the pressure drop is equal to or greater then
this value the Unit Control allows the unit to operate.
Field Wiring
None required.
Programming
The following item must be programmed through the
“Setpoints” section of the User Interface:
• “POA DX Prs Drop” – this parameter can be set
between 0.06” WC and 1.0” WC. The default
value is 0.10” WC.
MINIMUM COIL PRESSURE DROP
The Unit Control uses the pressure drop across the
evaporator coil as an indicator of the airow across the
coil. When the bypass damper opens, it bypasses air
around the evaporator coil. If too much air is bypassed
the pressure drop (airow) across the coil decreases.
This parameter establishes the minimum pressure drop
(airow) allowed across the evaporator coil.
Field Wiring
None required.
Programming
The following item must be programmed through the
“Setpoints” section of the User Interface:
• “Min DX Prs Drop” – this parameter can be set
between 0.20” WC and 1.0” WC. The default
value is 0.5” WC.
FLEXSYS (continued)

JOHNSON CONTROLS
12
FORM 145.05-SU2 (1207)
This feature enables the unit to lower the supply air
temperature to prevent the supply air dew point from
dropping below the under oor temperature.
Field Wiring
A 10K Type II thermistor must be located in the under
oor space and connected to IN-6 terminals 11 and 12
of the main control board.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “AC-S/A Dew En” must be set to ON
FLEXSYS DEW POINT TEMPERATURE CONTROL
• “AC-S/A Dew Min” set point must be pro-
grammed. The default value is 48.0˚ F. This is
the lowest supply air temperature the control can
use for dew point control.
• “AC-S/A Dew Max” set point must be pro-
grammed. The default value is 60.0˚ F. This is
the highest supply air temperature the control can
use for dew point control.
• “AC-S/A Dew Dif” set point must be pro-
grammed. The default value is 5.0˚ F. This value
is subtracted from the under oor temperature
and is used to establish a under oor dew point
supply air temperature set point.

13
JOHNSON CONTROLS
FORM 145.05-SU2 (1207)
WATER SIDE ECONOMIZER
The feature allows the unit to use a water side economizer
instead of or in conjunction with the compressors to
maintain the conditioned space conditions.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “H2O Econ En” – This parameter must be set to
ON. The default value is OFF
• “Econ-S/A Tmp En”- This parameter must be set
to ON if you want the water side economizer to
be controlled by a supply air temperature. The
default value is OFF.
• “Econ-R/A Tmp En”- This parameter must be set
to ON if you want the water side economizer to
be controlled by a return air temperature. The
default value is OFF
• “Econ Valve Min” – This parameter establishes
the minimum position of the water side econo-
mizer valve. The parameter can be set between
0 and 100%. The default value is 0%.
CONDENSER WATER BYPASS
The unit can be ordered with a water side economizer
valve, a condenser water by-pass valve, or none of
the above. If the unit is ordered with a condenser
water by-pass valve, the valve will operate inversely
to the operation of the condenser water valve. As
the condenser water valve opens to increase the ow
through the condenser, the water by-pass valve will
close to decrease the amount of by-pass.
Field Wiring
None required.
Programming
The following item must be programmed through the
“Setpoints” section of the User Interface:
 “BYPASS VALVE MAX” – This is the maximum
position of the condenser water by-pass valve.
The default value is 50%.

JOHNSON CONTROLS
14
FORM 145.05-SU2 (1207)
AIR SIDE ECONOMIZER
The feature allows the unit to use an air side economizer
instead of or in conjunction with the compressors to
maintain the conditioned space conditions.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “O/A Econ En” – This parameter must be set to
ON. The default value is OFF.
• “Econ-S/A Tmp En”- This parameter must be set
to ON if you want the water side economizer to
be controlled by a supply air temperature. The
default value is OFF.
• “Econ-R/A Tmp En”- This parameter must be set
to ON if you want the water side economizer to
be controlled by a return air temperature. The
default value is OFF.
• “O/A Damper Min” – This parameter establishes
the minimum position of the air side economizer
damper. The parameter can be set between 0 and
100%. The default value is 15%.

15
JOHNSON CONTROLS
FORM 145.05-SU2 (1207)
HEATING OPERATION - STAGED
HEATING SUPPLY AIR TEMPERATURE CONTROL
This feature allows the unit to control the heating
operation based on the difference between the supply air
temperature and the supply air temperature set point.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “HT STG -1/TRI-2” - For Staged Heat this pa-
rameter needs to be set to 1.
• “Heat-S/A Tmp En” must be set to ON. The
default is OFF.
• “Heat-S/A Tmp SP” set point must be pro-
grammed. It can be set between 40.0˚ F and
115.0˚ F. The default value is 110.0˚ F. This
is the supply air temperature the unit will try to
maintain in the heating mode.
HEATING RETURN AIR TEMPERATURE CONTROL
This feature allows the unit to control the heating
operation based on the difference between the return air
temperature and the return air temperature set point.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “HT STG -1/TRI-2” - For Staged Heat this pa-
rameter needs to be set to 1.
• “Heat-R/A Tmp En” must be set to ON. The
default is OFF.
• “Heat-R/A Tmp SP” set point must be pro-
grammed. It can be set between 40.0˚ F and 90.0˚
F. The default value is 72.0˚ F. This is the return
air temperature the unit will try to maintain.
HEATING SUPPLY AIR AND RETURN AIR
TEMPERATURE CONTROL
This feature allows the unit to control the heating
operation on either the temperature difference between
the supply air temperature and the supply air temperature
set point and the return air temperature and the return
air temperature set point. When both are selected the
compressors will be cycled based on the lesser of the
two differences.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “HT STG -1/TRI-2” - For Staged Heat this pa-
rameter needs to be set to 1.
• “Heat-S/A Tmp En” must be set to ON. The
default is ON.
• “Heat-S/A Tmp SP” set point must be pro-
grammed. It can be set between 40.0˚ F and
115.0˚ F. The default value is 110.0˚ F. This
is the supply air temperature the unit will try to
maintain in the heating mode.
• “Heat-R/A Tmp En” must be set to ON. The
default is OFF.
• “Heat-R/A Tmp SP” set point must be pro-
grammed. It can be set between 40.0˚ F and 90.0˚
F. The default value is 72.0˚ F. This is the return
air temperature the unit will try to maintain.

HEATING SUPPLY AIR TEMPERATURE CONTROL
This feature allows the unit to control the heating
operation based on the difference between the supply air
temperature and the supply air temperature set point.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “HT STG -1/TRI-2” - For Tristate Modulated
Heat this parameter needs to be set to 2.
• “Heat-S/A Tmp En” must be set to ON. The
default is OFF.
• “Heat-S/A Tmp SP” set point must be pro-
grammed. It can be set between 40.0˚ F and
115.0˚ F. The default value is 110.0˚ F. This
is the supply air temperature the unit will try to
maintain in the heating mode.
HEATING RETURN AIR TEMPERATURE CONTROL
This feature allows the unit to control the heating
operation based on the difference between the return air
temperature and the return air temperature set point.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “HT STG -1/TRI-2” - For Tristate Modulated
Heat this parameter needs to be set to 2.
• “Heat-R/A Tmp En” must be set to ON. The
default is OFF.
• “Heat-R/A Tmp SP” set point must be pro-
grammed. It can be set between 40.0˚ F and 90.0˚
F. The default value is 72.0˚ F. This is the return
air temperature the unit will try to maintain.
Tele. 800-861-1001
www.york.com
P.O. Box 1592, York, Pennsylvania USA 17405-1592 Subject to change without notice. Printed in USA
Copyright © by Johnson Controls 2006 ALL RIGHTS RESERVED
Form 145.05-SU2 (1207)
New Release
HEATING SUPPLY AIR AND RETURN AIR
TEMPERATURE CONTROL
This feature allows the unit to control the heating
operation on either the temperature difference between
the supply air temperature and the supply air temperature
set point and the return air temperature and the return
air temperature set point. When both are selected the
compressors will be cycled based on the lesser of the
two differences.
Field Wiring
None required.
Programming
The following items must be programmed through the
“Setpoints” section of the User Interface:
• “HT STG -1/TRI-2” - For Tristate Modulated
Heat this parameter needs to be set to 2.
• “Heat-S/A Tmp En” must be set to ON. The
default is ON.
• “Heat-S/A Tmp SP” set point must be pro-
grammed. It can be set between 40.0˚ F and
115.0˚ F. The default value is 110.0˚ F. This
is the supply air temperature the unit will try to
maintain in the heating mode.
• “Heat-R/A Tmp En” must be set to ON. The
default is OFF.
• “Heat-R/A Tmp SP” set point must be pro-
grammed. It can be set between 40.0˚ F and 90.0˚
F. The default value is 72.0˚ F. This is the return
air temperature the unit will try to maintain.
HEATING OPERATION - TRISTATE MODULATED