Trane SSC-APG002-EN, XR Series, XR 13, XR 15 Application Manual

Application Guide

Trane XR S tyle Condensing Units and Heat Pumps

SSC-APG002-EN

Low Outdoor Ambient Operation
Unit Mounting
Minimum Clearances

Trane XR Style Outdoor Models

The purpose of this bulletin is to provide application criteria as related to the Trane XR style condensing
units and heat pump units.

This bulletin discusses:
I. T erms and definitions
II. Off season cooling operation
III. Compressor crankcase heat requirements for split heat pump systems.
IV . Unit mounting
V . Minimum operating clearances
VI. Clearance from vents
VII. Nameplate electrical data

POSITION ST A TEMENT :

Trane has always recommended installing T rane approved, matched indoor and outdoor systems.
The benefits of installing approved matched sytems are maximum efficiency , optimum performance, and
best overall system reliability

W arnings and Cautions may appear throughout this manual. Read these carefully .

WARNING – Indicates a potentially hazardous situation which, if not avoided,

could result in death or serious injury.

CAUTION – Indicates a potentially hazardous situation which, if not avoided,

may result in minor or moderate injury. It may also be used to alert against unsafe
practices.

CAUTION – Indicates a situation that may result in equipment or property-damage-

only accidents.

ISSUED BY :
Product Application Engineering Department
Trane a company of Ingersoll Rand
T yler, T exas

© Trane 2015 Page 2 SSC-APG002-EN

Section I - T erms and Definitions:
Three phase products:

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.

Definitions and information:

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 Exp ansion 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 infor­mation.
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 BAYLOAM*** 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 volt­age 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 st art-up the potential relay contacts
are closed, therefore placing the start capacitor in the compressor circuit, as the com­pressor 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.

© Trane 2015 Page 3 SSC-APG002-EN

Section II – Off Season Cooling Operation

55°F - 30°F 55°F - 30°F 55°F - 30°F 55°F - 30°F 30°F - 20°F or 30°F - 0°F see lowest approved OD ambient

Air

Conditioner

Heat Pump

55 deg F. As

Manufactu red

Air

Conditioner

AY28X079 3

Heat Pump
AY28X084 3

TXV-NB CCHT

BAYLOAM103
BAYLOAM107

Start Kit

Solenoid

Valve (AC) 4

Windshield

Lowest App roved
Outdoor Ambient

Cooling Mode

13 SEER X X X X X BAYLOAM103 X X X Approved to 0 d eg F

14 SEER X X X X X BAYLOAM103 X X X

AC Approved to 20 deg F
HP Approved t o 10 deg F

15 SEER X X X X X BAYLOAM103 X X X

AC Approved to 20 deg F
HP Approved t o 10 deg F

16 SEER 1 , 2 X X X X X BAYLOAM107 1 X X X

AC Approved to 20 deg F
HP Approved t o 10 deg F

17 SEER X X X X X BAYLOAM103 X X X

AC Approved to 20 deg F
HP Approved t o 10 deg F

Notes:
1 DO NOT apply BAYLOAM to model t onnages wit h variable speed condenser fan motors
2 Models with VS co ndenser fan motors ar e approved to 30 deg F wit h EDC or air hand ler with EEV
3 AY28X*** EDC not required when indoor unit has EEV
4 Liquid line soleno id shall be used for isolation purposes. Also used if liquid line is 1/2" and located before t he evaporator coil if AC is ab ove ID coil
See SS-APG006-EN Refrigeration P iping A pplicatio n Guide

©Trane 2015 Page 4 SSC-APG002-EN

Trane outdoor units may be operated in the cooling mode to 55°F outdoor ambient 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 55°F.

Unit requires a compressor crankcase heater and start accessory only if it is not factory installed.
Compressor Crankcase Heaters:
Reciprocating Compressor: BAYCCHT300

Large Scroll Compressor: BAYCCHT301RES
Small Scroll Compressor: BAYCCHT302RES

As noted in the above table, systems may be operated lower than 55°F by applying the
BAYLOAM103 or BAYLOAM107 and other accessories. The BAYLOAM*** controller cycles
the outdoor fan motor 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 motor on approved products since
the controller does not vary the frequency to the motor. However the BAYLOAM*** CANNOT
be applied to those model tonnages with a variable speed condenser fan motor.

Windshields:

If low ambient cooling operation is required, windshields are a must in order to block prevailing winds from
impacting system performance at low outdoor temperatures. Reference figure 1.

Figure 1 - Windshield Construction Information

SHIELD DESIGN FOR
HIGHLY DIRECTIONAL WINDS

SERVICE
ACCESS
AREA
SEE NOTES

UNIT

12" MIN.

PREVAILING
WIND DIRECTION

SOLID PANEL

UNIT

4" MINIMUM

24" MAXIMUM

SHIELD DESIGNED FOR
NON-DIRECTIONAL WINDS

SERVICE
ACCESS
AREA
SEE NOTES

REMOVEABLE PANEL
OR GATE
FOR SERVICE

2 1/2" MIN.

UNIT

12" MIN.

SHADOW BOX FENCE
33% MIN. FREE AREA
EACH SIDE

UNIT

NOTE:

National Electrical Code
requires minimum three
feet clearance from the
service panel. Some local
building departments will
allow a removeable panel
in front of the unit service
access area. Otherwise the
distance between the
windshield and the unit’s
service access is required
to be a minimum of three
feet. Reference page 16 of
this document for National
Electric Code information

.

2" MINIMUM

4" MAXIMUM

Low ambient cooling utilizing the frost control in GAM5A and T AM4 indoor units:

The T AM4 and T AM7 fan coil units utilize an electronic expansion valve (EEV). W ith this enhancement the
controls that monitor the EEV also allow us to take advantage of monitoring coil temperature.

How it works:
The on-board electr onic controls include a r elay that will open when the indoor coil begins to fr ost.
When this occurs, the contacts to the YO circuit will open and de-energize the outdoor unit, provided
figure 2 and 3 are followed. When the YO circuit opens the outdoor unit is taken off line; however,

the indoor blower continues to operate, thus clearing the indoor coil of frost build-up.

Low ambient cooling utilizing thermostatic control found in the A Y28X079 and A Y28X084.

How it works:
These controls ar e thermally contr olled contacts with a capillary style sensor. The capillary tube is
inserted into the coil fins in between the tube rows. When the sensor detects 25F, the contacts open.
The contacts close when the coil temperature reaches 60F. When wired as shown in figures 4 and 5,
the outdoor unit is de-energized when the EDC contact opens and re-energizes when the EDC

contact closes.

© Trane 2015 Page 5 SSC-APG002-EN

Typical wiring the frost control located in TAM4 or TAM7 fan coil unit

Figure 2

Cooling split system and T AM4 or T AM7 fan Coil Unit

GAM5 or TAM7 Air handling unit

Cooling

unit

Y

B

*NOTE:

Y2 and BK is present
on TAM7 units and not
present on GAM5 or
TAM4.

W3
W2
W1

BK (see note*)
G

Y2 (see note*)
YI (in)
YO (out

O

R
B

Figure 3

Heat pump split system and T AM4 or T AM7 fan coil unit

GAM5 or TAM7 Air handling unit

Thermostat

W

G

Y

R

B

Thermostat

W3

Brown X2

Heat pump

unit

W2
W1

BK (see note*)

X2
W

G

G

Y2 (see note*)

Y

O

R
B

Yellow

Orange

Red

Blue

YI (in)
YO (out

O

R
B

Warning! High voltage present in the outdoor unit and indoor unit. Assure high
voltage power is disconnected using lockout / tag-out procedures if applicable
prior to connecting low voltage wiring.

© Trane 2015 Page 6 SSC-APG002-EN