Trane SSC-APG002-EN User guide

Application Guide
SSC-APG002-EN
For Trane XR Style Split Condensing Units and Heat Pumps
Low OD Ambient Operation
Unit Mounting
Minimum Clearances

Purpose:
The purpose of this bulletin is to provide cumulative application criteria as related to the Trane XR
style cooling units and heat pumps.
This bulletin discusses:
I. Definitions and terms
II. Off Season Cooling Operation
III. Unit Mounting
IV. Minimum Operating Clearances
ISSUED BY:
Product Application Engineering Department
Trane
Tyler, Texas
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POSITION STATEMENT:
The Trane Company has always recommended installing Trane approved, matched indoor
and outdoor systems. All Trane split systems with a nominal rating of 13 SEER and above
are listed in the ARI Certified Directory with thermostatic expansion valves (TXV) only.

Pg. 3
All 2.5 to 5 ton three phase split system cooling units and heat pumps are shipped from
the factory with compressor crankcase heat. Three phase compressor do not require
start capacitors or start relays.
CCHT - Compressor Crankcase Heater, sometimes called a compressor sump heater.
This device is designed to warm the compressor crankcase (or sump) in order to prevent
or deter refrigerant migration during the compressor off cycle. Compressor crankcase
heaters are required for low ambient cooling operation.
TXV - Thermostatic Expansion Valve. This is a type of refrigerant flow control device
designed to maintain constant superheat throughout the operating envelope. For low
ambient cooling applications, a non-bleed TXV is required.
Bleed TXV: This type of TXV will allow the refrigerant pressures between the high side
and low side to equalize through the valve during the off cycle.
Non Bleed TXV: This type of TXV will not allow the refrigerant pressures between the
high side and low side to equalize through the valve during the off cycle. When using this
type of valve on single phase units with reciprocating style compressors, compressor
start components are required. Check product data specifications for most current infor-
mation.
Head pressure controller - A device that is field installed on a condensing unit or heat
pump designed to maintain system head pressure that will allow safe system operation
without indoor coil icing in colder outdoor ambients. The BAYLOAM103 will cycle the
condenser fan motor in order to achieve adequate operating head pressure. The control
is adjustable.
Evaporator Defrost Control - A device that is field installed on the system’s indoor coil
in order to prevent the system from running during the cooling cycle when the indoor coil
approaches or reaches a temperature in which frost will form on the coil surface. When
the indoor coil approaches a safe temperature for cooling operation, the control will close
and allow the outdoor unit to restart. This controller makes and breaks the control volt-
age to the condensing unit.
Quick Start Component - This component may be factory installed or offered as a field
installed accessory ( BAYKSKT***). A quick start kit consist of a capacitor with a high
microfarad rating and a potential relay. It is installed so that the start capacitor is wired in
parallel with the compressor’s run capacitor. Prior to start-up the potential relay contacts
are closed, therefore placing the start capacitor in the compressor circuit, as the com-
pressor motor reaches operating speed, electrical current flows through the potential
relay’s coil and the the relay contacts are opened, thus taking the start capacitor out of
the system until the next compressor start up.
Unit Base Size - Unit base size may be determined by looking at the cabinet size. This is
located on the unit dimension page in product data or the installation manual. Dimensions
are also noted in this document. However, for the most up to date information, the Instal-
lation manual and / or product data should be referenced.
Definitions and information:
Three phase products:

Section I - Off Season Cooling Operation:
The Trane XR models may be operated in the cooling mode to 45oF as shipped from the factory when
applied with an indoor TXV. Where required, these units, with appropriate accessories, may be
applied to operate at outdoor temperatures below 450F.
Please refer to the accessory table below when determining if the desired model unit will operate at the
specified conditions and required accessories
AY28X079: Cooling only
AY28X084: Heat pumps
Head Pressure Controller:
BAYLOAM103: Approved for heat pumps and cooling units
Evaporator Defrost Control Kits:
Compressor Crankcase Heaters:
Reciprocating Compressor: BAYCCHT300
Scroll Compressor: BAYCCHT301
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As noted in the above table, the XR13 outdoor units may be operated to 0oF if necessary, by applying
the BAYLOAM103 head pressure controller and other required accessories. The BAYLOAM103 is a
newly developed head pressure controller that cycles the OD fan as needed to maintain liquid line
temperature as set by the DIP switches located on the control. There is no need to change the outdoor
fan motor on approved products since the controller does not vary the frequency to the motor. For
more information publication number 18-HE46D1-1or latest version, should be consulted.
* Unit requires a compressor crankcase heater and start accessory only if it is not factory installed.
Check general specifications located in product data to determine if unit is equipped with factory
installed quick start components.
* *Solenoid valve required if:
1. Liquid line is one size larger than factory connection. (example: factory connection is 3/8” and the
existing liquid line is 1/2”) Please refer to publication 32-3009-03 or latest edition for approved line sizes.
2. Off cycle time will be longer than 30 minutes during low ambient cooling operation.
More Information:
Wind Shields:
Please refer to page 14 of this document for information regarding wind shields when low ambient cooling
operation is required.
Ambient Temperature in Cooling Mode Operation
Model
Family 45 F 30 F 0 F
2TTR3 As Shipped AY28X079 CCHT* BAYLOAM103 AY28X079 Quick Start
Accessory CCHT* Solenoid
Valve**
2TWR3 As Shipped AY28X084 CCHT* BAYLOAM103 AY28X084 Quick Start
Accessory CCHT*
4TTR3 As Shipped AY28X079 CCHT* BAYLOAM103 AY28X079 Quick Start
Accessory CCHT* Solenoid
Valve**
4TWR3 As Shipped AY28X084 CCHT* BAYLOAM103 AY28X084 Quick Start
Accessory CCHT*
2TTR4 As Shipped AY28X079 CCHT* Not Approved
2TWR4 As Shipped AY28X084 CCHT* Not Approved
4TTR4 As Shipped AY28X079 CCHT* Not Approved
4TWR4 As Shipped AY28X084 CCHT* Not Approved

Typical wiring when using the evaporator defrost control (EDC):
Cooling Split System and AY28X079 Evaporator Defrost Control
R
Y
G
W
B
Red (R)
Y
Y Low
Orange
Green (G)
White (W1)
White (W2)
White (W3)
Blue (B)
R
Y
O
G
W
X2
B
Red
Yellow
Orange
Brown / X2
Blue
EDR-1
EDC
EDR
Y
B
Red (R)
Y
Y Low
Green (G)
White (W1)
White (W2)
White (W3)
Blue (B)
EDC
Heat Pump Split System and AY28X084 Evaporator Defrost Control
Thermostat
Air handling unit
Thermostat
Pg. 5
Heat pump
unit
Air handling unit
Cooling
unit

SECTION II - Unit Mounting:
This section describes appropriate methods for mounting and securing the XR13 and XR14 style split
system cooling and heat pump units. However, if these units are to be mounted in a region where high
winds are an issue, please refer to the Trane BAYECMT001 extreme conditions mounting kit. In
seizmic zones the unit shall be secured according to local code; this may require a local P.E.’s stamp.
When mounting or securing Trane residential style condensing units and heat pumps please observe the
following.
1. Anytime the unit is to be supported from the edge, the supporting material must extend minimum two
inches beyond the perimeter of the unit’s base.
2. The mounting hole locations are molded in the basepan, however, must be drilled through.
a) Hole locations are identified on page 7 and 8 of this document as well as the unit installation guide.
3. Washers should be placed in between the fastener head and the basepan.
4. Trane recommends supporting the center of the unit with a cross member if unit is not mounted on
plate.
5. Base 2, 3, and 4 pans have four mounting hole locations.
6. Drill size / bolt diameter shall be 5/16”.
Drawings for illustration purposes only.
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If supporting the base pan from the perimeter, the support must extend under the base pan at least 2”. Trane recommends
supporting the middle of the base pan with a cross member.
support must extend 2” from the basepan perimeter
support center of unit
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BASE PAN MOUNTING HOLE LOCATIONS
( location only, holes must be drilled )

BASE PAN MOUNTING HOLE LOCATIONS
( location only, holes must be drilled )
support must extend 2” from the basepan perimeter
support center of unit
support must extend 2” from the basepan perimeter
support center of unit
If supporting the base pan from the perimeter, the support must extend under the base pan at least 2”. Trane recommends
supporting the middle of the base pan with a cross member.
Pg 8

Section III - Minimum Operating Clearances
This section discusses installating the XR style condensing unit / heat pump where spacing is limited.
When installing Trane outdoor units in a location where clearance to other units, walls, fences, etc. is
limited, the concerns listed below must be addressed:
1. System Operation - Adequate airflow must be provided to and away from the condensing unit / heat
pump in order to enable appropriate heat transfer. If this is accomplished, head pressure will remain
within an effective operating range.
2. System Servicability - Sufficient working space must be allowed for the HVAC service technician to
properly maintain the condensing unit / heat pump. Furthermore, space must be allowed for major
component change out in the event of a failure. Working space is determined by the Local, State and
National Codes. (See National Electric Code Table 110.26 for explanation.)
3. Space Maintenance - Appropriate area must be allowed in order to maintain the ground area where
the units are positioned to prohibit debris from collecting on the panels, thus further providing
unobstructed airflow to the condensing unit.
3. State, Local Codes, and National Codes shall prevail. Check with the local jurisdiction before
installation to assure compliance.
Numerous projects require minimum clearances between outdoor units and adjacent walls, fences and other
units. The obstruction in question is usually one of the following:
1. One or more walls of an adjacent building.
2. Fences or barriers provided to reduce sound transmission or visually screen the equipment.
3. Other outdoor units in a multi-unit installation.
4. Acombination of the above.
5. Overhangs
The prime considerations involved in establishing minimum clearances are:
1.Adequate airflow to the outdoor coil with minimum recirculation.
2. Service access to the equipment.
3. Compliance with the National Electric Code and other applicable codes.
4. Design temperature - Design temperatures greater than 105F require additional consideration.
I. In order to assure that adequate airflow reaches the condensing unit, size free air passages at 300
Feet Per Minute maximum velocity. See condensing unit airflow performance on page 23 of this
document.
II. The importance of providing proper service access to equipment cannot be overemphasized. The HVAC
service technician’s job may be performed with greater ease and lower cost if adequate service space is
allowed.
III. Knowledge of the National Electric Code and other applicable codes for the job sight location is a
necessity in order to satisfy local inspectors. These codes are in place for service as well as safety.
IV. Be sure to read all provisions and footnotes contained in this document. When ambient temperatures
exceed 105F, more space may be required for minimum operating clearances.
Pg. 9

1. Installation of a single condensing unit / heat pump in a corner with free air space on top.
A) For locations where the design ambient temperature is below 105F:
1) 1.0 feet clearance on 2 sides - If shrubbery is to be placed by the unit other side, then allow 1.0
Feet minimum clearance from the unit
2) Service access side requires 3 feet minimum clearance. Consult Local, State, and National
Electric Codes for minimum service clearance.
B) For locations where the design ambient temperature exceeds 105F:
1) 1.5 feet clearance on 2 walls. - If shrubbery is to be placed by the unit other side, then allow 1.0
Feet minimum clearance from the unit.
2) Service access side requires 3 feet minimum clearance.
C) If unit is located in such a way that service panel is facing the wall
1) NEC requires 3 feet minimum clearance between the unit and the wall
a) This space may be increased to 3 1/2 feet. Consult the National Electric Code for more
information regarding minimum clearances for working spaces.
2. Installation of two or more units where two adjacent walls form a corner.
A) For locations where the design ambient temperature is below 105F:
1) Note the unit base size and obtain the minimum clearance values from the table below.
B) For locations where the design ambient temperature exceeds 105F:
1) 2.0 feet clearance from both walls.
2) 3.0 feet clearance in between units, unless service panels face each other. (if service panels
face each other, this clearance may be increased to 4 feet per NEC)
C) If unit’s are located in such a way that the service panels are facing the wall
1) NEC requires minimum 3 feet between the unit and the wall
a) This space may be increased to 3 1/2 feet. Consult the most current edition of the National
Electric Code for more information regarding minimum clearances for working spaces.
SERVICE ACCESS PANEL SIDE 3’minimum clearance
Service Panel
-1.0’-
min
-1.0’-
min
A
A
A
A2B 2B
Pg. 10
-1.0’-
min
3.0’ min 5 feet minimum unrestricted top
clearance shall be provided.
5 feet minimum unrestricted top
clearance shall be provided.
eziSesaBAB
ecivreS
ecnaraelC
2'0.1'0.1"63
3'2.1'2.1"63
4'5.1'4.1"63
minimum clearance table