Fujitsu FO20R Series User manual

VARIABLE SPEED R-410A
HEAT PUMP OUTDOOR UNITS
INSTALLATION INSTRUCTIONS
92-105074-16-01 ( / ) Printed in USA
[ ] indicates metric conversions.
Do not destroy this manual.
Please read carefully and
keep in a safe place for future
reference by a serviceman.
WARNING
THESE INSTRUCTIONS
ARE INTENDED AS AN AID
TO QUALIFIED, LICENSED
SERVICE PERSONNEL FOR
PROPER INSTALLATION,
ADJUSTMENT, AND
OPERATION OF THIS UNIT.
READ THESE INSTRUCTIONS
THOROUGHLY BEFORE
ATTEMPTING INSTALLATION
OR OPERATION. FAILURE
TO FOLLOW THESE
INSTRUCTIONS MAY
RESULT IN IMPROPER
INSTALLATION,
ADJUSTMENT, SERVICE,
OR MAINTENANCE
POSSIBLY RESULTING IN
FIRE, ELECTRICAL SHOCK,
PROPERTY DAMAGE,
PERSONAL INJURY, OR
DEATH.
FO20R (20 SEER) EQUIPPED WITH
DIGITAL COMMUNICATIONS
WARNING:
RECOGNIZE THIS SYMBOL
AS AN INDICATION OF
IMPORTANT SAFETY
INFORMATION

Contents
2
CONTENTS
1.0 IMPORTANT SAFETY INFORMATION.......................................................3
2.0 GENERAL INFORMATION.....................................................................4-5
Ϯϭ/ŶƚƌŽĚƵĐƟŽŶϰ
ϮϮŐĞŶĐLJWĞƌĨŽƌŵĂŶĐĞƵĚŝƚdĞƐƟŶŐEŽƟĐĞϰ
Ϯϯ/ŵƉŽƌƚĂŶĐĞŽĨĂYƵĂůŝƚLJ/ŶƐƚĂůůĂƟŽŶϰ
Ϯϰ^LJƐƚĞŵ^ŝnjŝŶŐĂŶĚ^ĞůĞĐƟŽŶϰ
2.5 Importance of Proper Indoor/Outdoor Match-Ups..............................5
2.6 Checking Product Received...................................................................5
ϮϳŽŵƉƌĞƐƐŽƌƌĞĂŬͲ/ŶEŽƟĐĞϱ
3.0 UNIT SPECIFICATIONS..........................................................................5-6
ϯϭDŽĚĞůEƵŵďĞƌEŽŵĞŶĐůĂƚƵƌĞĂŶĚǀĂŝůĂďůĞDŽĚĞůƐϱ
3.2 Electrical and Physical Data ..................................................................6
4.0 INSTALLATION...................................................................................7-25
ϰϭdŽŽůƐΘZĞĨƌŝŐĞƌĂŶƚϳ
ϰϭϭdŽŽůƐZĞƋƵŝƌĞĚĨŽƌ/ŶƐƚĂůůŝŶŐΘ^ĞƌǀŝĐŝŶŐZͲϰϭϬDŽĚĞůƐϳ
ϰϭϮ^ƉĞĐŝĮĐĂƟŽŶƐŽĨZͲϰϭϬϳ
ϰϭϯYƵŝĐŬZĞĨĞƌĞŶĐĞ'ƵŝĚĞĨŽƌZͲϰϭϬϳ
ϰϮŚŽŽƐŝŶŐĂ>ŽĐĂƟŽŶϴ
ϰϮϭůůŽǁĂďůĞůĞĂƌĂŶĐĞƐϴ
ϰϮϮKƉĞƌĂƟŽŶĂů/ƐƐƵĞƐZĞůĂƚĞĚƚŽhŶŝƚ>ŽĐĂƟŽŶϴ
ϰϮϯŽƌƌŽƐŝǀĞŶǀŝƌŽŶŵĞŶƚƐϵ
ϰϮϰƵƐƚŽŵĞƌ^ĂƟƐĨĂĐƟŽŶ/ƐƐƵĞƐϵ
ϰϯDŽƵŶƟŶŐhŶŝƚϵ
ϰϯϭhŶŝƚͲDŽƵŶƟŶŐDĞƚŚŽĚƐϵ
ϰϯϮ,ŝŐŚtŝŶĚĂŶĚ^ĞŝƐŵŝĐdŝĞͲŽǁŶDĞƚŚŽĚƐϵ
ϰϯϯůĞǀĂƟŶŐhŶŝƚϭϬ
ϰϯϰ'ƌŽƵŶĚ^ŶŽǁĞƉƚŚdĂďůĞϭϬ
ϰϰZĞĨƌŝŐĞƌĂŶƚ>ŝŶĞ^Ğƚ^ĞůĞĐƟŽŶϭϭ
ϰϰϭZĞƉůĂĐŝŶŐdžŝƐƟŶŐ^LJƐƚĞŵƐϭϭ
ϰϰϮ>ŝŶĞ^ĞƚƉƉůŝĐĂƟŽŶŽŶƐŝĚĞƌĂƟŽŶƐϭϭ
ϰϰϮϭKŝůZĞƚƵƌŶƚŽŽŵƉƌĞƐƐŽƌϭϭ
ϰϰϮϮZĞĨƌŝŐĞƌĂŶƚDŝŐƌĂƟŽŶƵƌŝŶŐKīLJĐůĞϭϭ
ϰϰϮϯDĂdžŝŵƵŵ>ŝƋƵŝĚWƌĞƐƐƵƌĞƌŽƉϭϭ
ϰϰϮϰ>ŝƋƵŝĚ>ŝŶĞZĞĨƌŝŐĞƌĂŶƚ&ůĂƐŚŝŶŐϭϭ
ϰϰϮϱŽŵƉƌĞƐƐŽƌKŝů>ĞǀĞůĚũƵƐƚŵĞŶƚϭϮ
ϰϰϮϲĂƉĂĐŝƚLJ>ŽƐƐĞƐϭϮ
ϰϰϯ>ŝŶĞ^Ğƚ>ĞŶŐƚŚĂŶĚ&ŝƫŶŐ>ŽƐƐĞƐϭϮ
ϰϰϰ>ŝƋƵŝĚ>ŝŶĞ^ĞůĞĐƟŽŶϭϯ
ϰϰϱsĂƉŽƌ>ŝŶĞ^ĞůĞĐƟŽŶϭϯ
ϰϱ>ŝŶĞ^Ğƚ/ŶƐƚĂůůĂƟŽŶϭϲ
ϰϱϭ/ŵƉŽƌƚĂŶƚdƵďŝŶŐ/ŶƐƚĂůůĂƟŽŶWƌĂĐƟĐĞƐϭϲ
ϰϱϮZĞůĂƟǀĞ>ŽĐĂƟŽŶŽĨ/ŶĚŽŽƌĂŶĚKƵƚĚŽŽƌhŶŝƚƐϭϳ
ϰϱϮϭ/ŶĚŽŽƌĂŶĚKƵƚĚŽŽƌhŶŝƚEĞĂƌ^ĂŵĞ>ĞǀĞůϭϳ
ϰϱϮϮKƵƚĚŽŽƌhŶŝƚĞůŽǁ/ŶĚŽŽƌhŶŝƚϭϴ
ϰϱϮϯKƵƚĚŽŽƌhŶŝƚďŽǀĞ/ŶĚŽŽƌhŶŝƚϭϵ
ϰϱϯdƵďŝŶŐŽŶŶĞĐƟŽŶƐϮϬ
ϰϲ/ŶŝƟĂů>ĞĂŬdĞƐƟŶŐϮϭ
ϰϳǀĂĐƵĂƟŽŶ .........................................................................................21
ϰϴ&ŝŶĂů>ĞĂŬdĞƐƟŶŐϮϮ
ϰϵŽŶƚƌŽůtŝƌŝŶŐ...................................................................................22
ϰϵϭ Digital
ŽŵŵƵŶŝĐĂƟŽŶƐϮϮ
ϰϵϮŝŐŝƚĂů ŽŶƚƌŽůĞŶƚĞƌ/ŶƐƚĂůůĂƟŽŶϮϮ
ϰϵϯŝŐŝƚĂůŽŵŵƵŶŝĐĂƟŽŶtŝƌŝŶŐŽŶŶĞĐƟŽŶƐϮϮ
ϰϵϰ
ŽŶǀĞŶƟŽŶĂůϮϰsdŚĞƌŵŽƐƚĂƚŽŶƚƌŽůtŝƌŝŶŐŽŶŶĞĐƟŽŶƐ ........23
ϰϭϬWŽǁĞƌtŝƌŝŶŐϮϰ
ϰϭϭ'ƌŽƵŶĚŝŶŐϮϱ
5.0 SYSTEM START-UP AND REFRIGERANT CHARGING...........................25-29
ϱϭ^LJƐƚĞŵ^ƚĂƌƚͲhƉKǀĞƌǀŝĞǁϮϱ
ϱϮ/ŶŝƟĂůWŽǁĞƌhƉĂŶĚŽŵŵƵŶŝĐĂƟŽŶsĞƌŝĮĐĂƟŽŶϮϱ
5.3 DigitalŽŶƚƌŽůĞŶƚĞƌ^ĞƚͲhƉϮϱ
ϱϰ/ŶŝƟĂů^LJƐƚĞŵ^ĞƚͲhƉϮϱ
5.5
^ĞƫŶŐƵƉŚĂƌŐŝŶŐDŽĚĞhƐŝŶŐŝŐŝƚĂůŽŶƚƌŽůĞŶƚĞƌ^ĞƌǀŝĐĞDĞŶƵ .........26
5.6 ^ĞƫŶŐƵƉŚĂƌŐŝŶŐDŽĚĞhƐŝŶŐsĂƌŝĂďůĞ^ƉĞĞĚKƵƚĚŽŽƌŽŶƚƌŽůDĞŶƵ ....26
ϱϳ/ŶĚŽŽƌŝƌͲ&ůŽǁsĞƌŝĮĐĂƟŽŶϮϳ
ϱϴZĞĨƌŝŐĞƌĂŶƚŚĂƌŐŝŶŐϮϳ
ϱϴϭ
DĞĂƐƵƌĞŵĞŶƚĞǀŝĐĞ^ĞƚͲhƉϮϴ
ϱϴϮWƌĞůŝŵŝŶĂƌLJŚĂƌŐŝŶŐďLJtĞŝŐŚƚϮϴ
ϱϴϯWƌĞůŝŵŝŶĂƌLJŚĂƌŐŝŶŐďLJWƌĞƐƐƵƌĞƐϮϴ
ϱϴϰ&ŝŶĂůŚĂƌŐŝŶŐďLJ>ŝƋƵŝĚ^ƵďĐŽŽůŝŶŐϮϵ
ϱϴϱZͲϰϭϬdĞŵƉĞƌĂƚƵƌĞWƌĞƐƐƵƌĞŚĂƌƚϮϵ
ϱϵŽŵƉůĞƟŶŐ/ŶƐƚĂůůĂƟŽŶϮϵ
6.0 NORMAL SEQUENCEOF OPERATION..................................................30-32
ϲϭŽŽůŝŶŐDŽĚĞϯϬ
ϲϮKŶͲĞŵĂŶĚŽŽůŝŶŐĞŚƵŵŝĚŝĮĐĂƟŽŶϯϬ
ϲϯ>ŽǁŵďŝĞŶƚŽŽůŝŶŐKƉĞƌĂƟŽŶϯϬ
ϲϰ,ĞĂƟŶŐDŽĚĞϯϬ
ϲϱ^ƵƉƉůĞŵĞŶƚĂůůĞĐƚƌŝĐ,ĞĂƚƵƌŝŶŐ,ĞĂƟŶŐDŽĚĞϯϭ
ϲϲƵĂů&ƵĞůƉƉůŝĐĂƟŽŶƐͲ,ĞĂƟŶŐDŽĚĞϯϭ
6.7 Demand Defrost.................................................................................31
ϲϴ
^ĞƋƵĞŶĐĞŽĨKƉĞƌĂƟŽŶĨŽƌŽŶǀĞŶƟŽŶĂůϮϰsdŚĞƌŵŽƐƚĂƚŽŶƚƌŽůƐ ...........32
7.0 COMPONENTS AND CONTROLS......................................................33-39
7.1 Accumulator.......................................................................................33
7.2 Choke/Inductor .................................................................................33
7.3 Coil Temperature Thermistor.............................................................33
ϳϰŽŵƉƌĞƐƐŽƌϯϯ
ϳϱŝƐĐŚĂƌŐĞ>ŝŶĞdŚĞƌŵŝƐƚŽƌϯϯ
ϳϲsĂƌŝĂďůĞ^ƉĞĞĚKƵƚĚŽŽƌŽŶƚƌŽů;s^KͿϯϰ
ϳϲϭŽĂƌĚ&ĞĂƚƵƌĞƐĂŶĚŽŶŶĞĐƟŽŶƐϯϰ
ϳϲϮd^dΘ^tϮƵƩŽŶƐϯϱ
7.6.3 Memory Card ...........................................................................35
ϳϲϰ&ĂĐƚŽƌLJ^ƵƉĞƌŚĞĂƚ^ĞƫŶŐϯϱ
ϳϲϱ^ƵƉĞƌŚĞĂƚKīƐĞƚ/W^ǁŝƚĐŚ^ĞƫŶŐƐϯϱ
ϳϲϲĞĨƌŽƐƚdĞƌŵŝŶĂƟŽŶdĞŵƉĞƌĂƚƵƌĞ/W^ǁŝƚĐŚĞĚϯϱ
ϳϲϳDĞŶƵ^ƚƌƵĐƚƵƌĞϯϲ
ϳϲϴZĞƉůĂĐĞŵĞŶƚŽĨƚŚĞs^Kϯϲ
ϳϳůĞĐƚƌŽŶŝĐdžƉĂŶƐŝŽŶsĂůǀĞϯϳ
ϳϴ&ŝůƚĞƌΘ&ĞƌƌŝƚĞZŝŶŐƐϯϳ
ϳϵ,ŝŐŚWƌĞƐƐƵƌĞŽŶƚƌŽůϯϴ
ϳϭϬ>ŝƋƵŝĚWƌĞƐƐƵƌĞdƌĂŶƐĚƵĐĞƌϯϴ
ϳϭϭ>ŝƋƵŝĚdĞŵƉĞƌĂƚƵƌĞdŚĞƌŵŝƐƚŽƌϯϴ
7.12 KƵƚĚŽŽƌŵďŝĞŶƚdĞŵƉĞƌĂƚƵƌĞdŚĞƌŵŝƐƚŽƌϯϴ
ϳϭϯKƵƚĚŽŽƌ&ĂŶDŽƚŽƌϯϴ
ϳϭϰKƵƚĚŽŽƌ&ĂŶůĂĚĞϯϴ
ϳϭϱWŽǁĞƌ/ŶǀĞƌƚĞƌŽŵƉƌĞƐƐŽƌŽŶƚƌŽůϯϴ
ϳϭϲ^ƵĐƟŽŶWƌĞƐƐƵƌĞdƌĂŶƐĚƵĐĞƌϯϵ
ϳϭϳ^ƵĐƟŽŶdĞŵƉĞƌĂƚƵƌĞdŚĞƌŵŝƐƚŽƌϯϵ
8.0 ACTIVE SYSTEM PROTECTION FEATURES..........................................40-42
ϴϭDŝŶŝŵƵŵZƵŶdŝŵĞƌϰϬ
ϴϮKŝůZĞƚƵƌŶLJĐůĞϰϬ
ϴϯKīͲLJĐůĞZĞĨƌŝŐĞƌĂŶƚDŝŐƌĂƟŽŶʹ^ƚĂƚŽƌ,ĞĂƚ ϰϬ
ϴϰ,ŝŐŚŝƐĐŚĂƌŐĞdĞŵƉĞƌĂƚƵƌĞϰϬ
ϴϱ,ŝŐŚŝƐĐŚĂƌŐĞWƌĞƐƐƵƌĞϰϬ
ϴϲ>Žǁ^ƵĐƟŽŶWƌĞƐƐƵƌĞ>ŽƐƐŽĨŚĂƌŐĞϰϬ
ϴϳ
ŽŵƉƌĞƐƐŽƌ^ŚƵƚͲŽǁŶ^ĞƋƵĞŶĐĞĨŽƌ,ŝŐŚŽƌ>ŽǁZĞĨƌŝŐĞƌĂŶƚWƌĞƐƐƵƌĞ&ĂƵůƚ ϰϭ
ϴϴKǀĞƌĐƵƌƌĞŶƚĂŶĚƵƌƌĞŶƚ/ŵďĂůĂŶĐĞϰϭ
ϴϵŽŵƉƌĞƐƐŽƌKƉĞƌĂƟŽŶKƵƚƐŝĚĞŶǀĞůŽƉĞϰϭ
ϴϭϬKǀĞƌĂŶĚhŶĚĞƌsŽůƚĂŐĞϰϭ
ϴϭϭ/ŶǀĞƌƚĞƌKǀĞƌdĞŵƉĞƌĂƚƵƌĞϰϭ
ϴϭϮŽŶƚƌŽůƐĂŶĚŽŵŵƵŶŝĐĂƟŽŶDĂůĨƵŶĐƟŽŶϰϭ
ϴϭϯ^ĞŶƐŽƌ&ĂŝůƵƌĞĞĨĂƵůƚKƉĞƌĂƟŽŶϰϮ
ϴϭϰdžŝƟŶŐĐƟǀĞWƌŽƚĞĐƟŽŶ>ŽĐŬͲKƵƚDŽĚĞϰϮ
9.0 DIAGNOSTICS AND TROUBLESHOOTING.........................................43-72
ϵϭ&ĂƵůƚZĞĐĂůůWƌŽĐĞĚƵƌĞϰϯ
ϵϮŽŵƉƌĞƐƐŽƌ&ĂŶDŽƚŽƌdĞƐƚDŽĚĞϰϯ
ϵϯĞĨƌŽƐƚdĞƐƚDŽĚĞϰϯ
ϵϰ^ƚĂƚƵƐĂŶĚŝĂŐŶŽƐƟĐŽĚĞƐϰϰ
ϵϱĐƟǀĞWƌŽƚĞĐƟŽŶ&ĂƵůƚĞƚĂŝůƐϱϮ
ϵϲůĞĐƚƌŝĐĂůŚĞĐŬƐ&ůŽǁĐŚĂƌƚϱϵ
ϵϳŽŽůŝŶŐDĞĐŚĂŶŝĐĂůŚĞĐŬƐ&ůŽǁĐŚĂƌƚ ϲϬ
ϵϴ,ĞĂƟŶŐDĞĐŚĂŶŝĐĂůŚĞĐŬƐ&ůŽǁĐŚĂƌƚ .............................................61
ϵϵĞĨƌŽƐƚDĞĐŚĂŶŝĐĂůŚĞĐŬƐ&ůŽǁĐŚĂƌƚϲϮ
ϵϭϬŚĞĐŬŝŶŐdƌĂŶƐĚƵĐĞƌƐĂŶĚdĞŵƉĞƌĂƚƵƌĞ^ĞŶƐŽƌƐϲϯ
ϵϭϭ'ĞŶĞƌĂůdƌŽƵďůĞƐŚŽŽƟŶŐ'ƵŝĚĞϲϱ
ϵϭϮ^ĞƌǀŝĐĞŶĂůLJnjĞƌŚĂƌƚƐ ....................................................................66
ϵϭϯdƌŽƵďůĞƐŚŽŽƟŶŐdŝƉƐϳϮ
10.0 OUTDOOR UNIT MAINTENANCE .........................................................73
ϭϬϭ KƵƚĚŽŽƌ Žŝů ůĞĂŶŝŶŐ ϳϯ
ϭϬϮ ĂďŝŶĞƚ ůĞĂŶŝŶŐ ĂŶĚ ĂƌĞ ϳϯ
ϭϬϯ DŽƚŽƌ >ƵďƌŝĐĂƟŽŶ ϳϯ
ϭϬϰ ZĞƉůĂĐĞŵĞŶƚ WĂƌƚƐ ϳϯ
11.0 WIRING DIAGRAM ..............................................................................74
12.0 APPENDIX ......................................................................................75-76
ϭϮϭŐĞŶĐLJWĞƌĨŽƌŵĂŶĐĞƵĚŝƚdĞƐƚ/ŶƐƚƌƵĐƟŽŶƐϳϱ

Safety
3
1.0 IMPORTANT SAFETY INFORMATION
WARNINGS:
• These instructions are intended as an aid to
qualified, licensed service personnel for proper
installation, adjustment, and operation of this unit.
Read these instructions thoroughly before attempting
installation or operation. Failure to follow these
instructions may result in improper installation,
adjustment, service, or maintenance possibly
resulting in fire, electrical shock, property
damage, personal injury, or death.
• The unit must be permanently grounded. Failure
to do so can cause electrical shock resulting in
severe personal injury or death.
• Turn off electric power at the fuse box or service
panel before making any electrical connections.
• Complete the ground connection before making
line voltage connections. Failure to do so can
result in electrical shock, severe personal injury,
or death.
• Disconnect all power to unit before starting
maintenance. Failure to do so can cause
electrical shock resulting in severe personal
injury or death.
• Never assume the unit is properly wired and/or
grounded. Always test the unit cabinet with a
noncontact voltage detector available at most
electrical supply houses or home centers before
removing access panels or coming into contact
with the unit cabinet.
• DO NOT use oxygen to purge lines or pressurize
system for leak test. Oxygen reacts violently with
oil, which can cause an explosion resulting in
severe personal injury or death.
• The top of the scroll compressor shell is hot.
Touching the compressor top may result in serious
personal injury.
• The manufacturer’s warranty does not cover
any damage or defect to the unit caused by the
attachment or use of any components, accessories,
or devices (other than those authorized by the
manufacturer) into, onto, or in conjunction with the
heat pump. You should be aware that the use
of unauthorized components, accessories, or
devices may adversely affect the operation
of the heat pump and may also endanger life
and property. The manufacturer disclaims any
responsibility for such loss or injury resulting
from the use of such unauthorized components,
accessories, or devices.
• This product is not approved for installation at
2000 meters [6561 feet] above sea level or higher.
Installation at higher altitudes may result in control
and unit failures due to electrical arc tracking
between electrical components on the invertor drive
control board. Possibly resulting in fire, electrical
shock, property damage, personal injury, or death.
CAUTIONS:
• R-410A systems operate at approximately 60% higher
pressures (1.6 times) than R-22 systems. Do not use
R-22 service equipment or components on R-410A
equipment. Use appropriate care when using this
refrigerant. Failure to exercise care may result in
equipment damage or personal injury.
• Only match this outdoor unit with a matched indoor
coil or air handler approved for use with this outdoor
unit per the unit manufacturer’s specification sheet.
The use of unmatched coils or air handler will likely
result in a charge imbalance between the cooling
and heating modes which can cause unsatisfactory
operation including a high-pressure switch lockout
condition.
• Only use indoor coils approved for use on R-410A
systems. An R-22 coil will have a TXV or fixed
expansion device that is not designed to operate
properly in an R-410A system and will result in
serious operational issues. The R-22 coil could also
contain a significant amount of mineral oil which
is incompatible with the POE oil used in R-410A
systems and could result in reliability issues with the
compressor and expansion devices.
• When the indoor coil or air handler is installed over
a finished ceiling and/or living area, it is required that
an auxiliary overflow pan be constructed and installed
under the entire indoor unit. Failure to do so can
result in property damage.
• UNIT MAY START SUDDENLY AND WITHOUT
WARNING. The 7 segment LED on the Outdoor
Control will flash c, C, h, or H when a call for unit
operation is present, but the unit is in temporary lock-
out. The heat pump/defrost control will attempt to start
unit after the anti-short cycle time expires, when a
high or low pressure control automatically resets, or
when the heat pump/defrost control exits the lockout
mode as the temperature rises above -10°F.

4
2.0 GENERAL INFORMATION
WARNING:
Improper installation, or installation not made in
accordance with these instructions, can result
in unsatisfactory operation and/or dangerous
conditions and can cause the related warranty
not to apply.
2.1 Introduction
The 20 SEER heat pumps are specifically
designed to operate with matching communicating
air-handlers, gas furnaces, and Control Center.
A conventional 24VAC 2-stage thermostat can
be used, but many features and benefits are
lost, so this is only recommended for emergency
situations when there are issues with the digital
communications and the system must be made
operational until the communication issues are
resolved.
This installation instruction manual contains
complete instructions for installation and setup
using communicating or conventional 24VAC
controls. Please refer to the manufacturer's
specification sheets for complete performance
data, thermostat, and accessory listings.
The information contained in this manual has
been prepared to assist in the proper installation,
operation, and maintenance of the air conditioning
system.
Read this manual and any instructions packaged
with separate equipment required to make up the
system prior to installation. Homeowner should
retain this manual for future reference.
2.2 Agency
Performance Audit
Testing Notice
For purposes of verifying or testing efficiency
ratings, the test procedure in Title 10 APPENDIX
M to Subpart B of Part 430 (Uniform Test Method
for Measuring the Energy Consumption of
Central Air Conditioners and Heat Pumps) and
the clarifying provisions provided in the AHRI
Operations Manual 210/240 that were applicable
at the date of manufacture should be used for
test set up and performance.
Should this unit be selected for performance audit
testing, follow the instructions included in the
Appendix (Section 12.1) of this manual.
2.3 Importance of
Quality Installation
A quality installation is critical to assure safety,
reliability, comfort, and customer satisfaction. Strict
adherence to applicable codes, the information in
this installation manual, the outdoor unit installation
manual, and the thermostat installation manual
are key to a quality installation. Read the entire
instruction manuals before starting the installation.
IMPORTANT: This product has been designed
and manufactured to meet certified AHRI capacity
and efficiency ratings with the appropriate outdoor
units. However, proper refrigerant charge, proper
airflow, and refrigerant line sizing are critical to
achieve optimum capacity and efficiency and to
assure reliable operation. Installation of this
product should follow the manufacturer’s refrigerant
charging and airflow instructions located in this
installation manual and the charging chart label
affixed to the outdoor unit. Failure to confirm
proper charge and airflow may reduce energy
efficiency and shorten equipment life.
The equipment has been evaluated in accordance
with the Code of Federal Regulations, Chapter XX,
Part 3280.
Install the unit in accordance with applicable
national, state, and local codes. Latest editions
are available from: “National Fire Protection
Association, Inc., Batterymarch Park, Quincy, MA
02269.” These publications are:
• ANSI/NFPA No. 70-(Latest Edition) National
Electrical Code.
• NFPA90A Installation of Air Conditioning and
Ventilating Systems.
• NFPA90B Installation of warm air heating and air
conditioning systems.
Install the unit in such a way as to allow necessary
access to the coil/filter rack and blower/control
compartment.
2.4 System Sizing and
Selection
Before specifying any heat pump equipment, a
survey of the structure and heat loss and heat
gain calculations must be made. A heat loss
calculation involves identifying all surfaces and
openings that lose heat to the surrounding air in
the heating mode and quantifying that heat loss. A
heat gain calculation makes similar measurements
and determines the amount of heat required to
General Information

5
2.0 GENERAL INFORMATION
3.0 UNIT SPECIFICATIONS
General Information Unit Specications
be removed in the cooling mode. A heat gain
calculation also calculates the extra heat load
caused by sunlight and by humidity removal. These
factors must be considered before selecting a
heat pump system to provide year-round comfort.
The Air Conditioning Contractors of America
(ACCA) Manual J method of load calculation is one
recognized procedure for determining the heating
and cooling load.
After the proper equipment combination has
been selected, satisfying both sensible and
latent requirements, the system must be properly
installed. Only then can the system provide the
comfort it was designed to provide.
There are several factors that installers must
consider.
• Outdoor unit location
• Indoor unit blower speed and airflow
• Proper equipment evacuation
• Supply and return air duct design and sizing
• Refrigerant charge
• System air balancing
• Diffuser and return air grille location and sizing
IMPORTANT: Excessive use of
elbows in the refrigerant line set can produce
excessive pressure drop. Follow industry
best practices for installation. Installation
and commissioning of this equipment is to
be performed by trained and qualified HVAC
professionals. For technical assistance, contact
your Distributor Service Coordinator.
2.5 Importance of
Proper Indoor/Outdoor
Match-Ups
To assure many years of reliable operation
and optimum customer comfort and to assure
the outdoor unit warranty remains valid, an air-
handler model or indoor coil/furnace combination
should be selected that is properly matched to the
outdoor unit. This is especially critical for heat
pump systems to assure proper refrigerant charge
balance between the cooling and heating modes.
The recommended approach is to select an air-
handler or indoor coil and gas furnace that has an
AHRI match with the outdoor unit. Refer to the
AHRI directory at www.ahridirectory.org to confirm
the air-handler and outdoor unit are a certified
combination in the AHRI Directory.
2.6 Checking Product
Received
Upon receiving unit, inspect it for any shipping
damage. Claims for damage, either apparent or
concealed, should be filed immediately with the
shipping company. Check model number, electrical
characteristics, and accessories to determine if they
are correct. Check system components (indoor coil,
outdoor unit, air handler/furnace, etc.) to make sure
they are properly matched.
2.7 Compressor
Break-In Notice
Prior to agency testing, system must be operated
for 20 hours at 115ºF [46.1ºC] outdoor ambient
temperature with 80ºF [26.7ºC] dry bulb 75ºF
[23.9ºC] wet bulb indoor ambient temperature to
break the compressor in.
FO2420RVJCAB
FO3620RVJCAB
FO4820RVJCAB
FO6020RVJCAB
AVAILABLE MODELS
3.1 Model Number Nomenclature and Available Models
FO
MAJOR SERIES
B – SECOND DESIGN SERIES
CONTROLS
C – COMMUNICATING
VOLTAGE
J = 1ph 208-230/60
TYPE
V – VARIABLE SPEED
MINOR SERIES
A – FIRST DESIGN SERIES
24 20 R V J CA B
PRODUCT CATEGORY
R – HEAT PUMP
SEER
20 - 20 SEER
CAPACITY
24 – 24,000 BTU
36 – 36,000 BTU
48 – 48,000 BTU
60 – 60,000 BTU
BRAND
FO – FUJITSU

6
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ALLOW 60” [1524mm]
OF CLEARANCE
AIR INLET LOUVERS ALLOW
6” [152mm] Min. OF CLEARANCE ALL SIDES
12” [305mm] RECCOMMENDED
SERVICE PANELS/
INLET CONNECTIONS / HIGH & LOW
VOLTAGE ACCESS
ALLOW 24”[ 610 mm] OF CLEARANCE
ST-A1226-23-00
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3.0 UNIT SPECIFICATIONS
Unit Specications
3.2 Electrical and Physical Data
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7
Tools
4.0 INSTALLATION
4.1 Tools and Refrigerant
4.1.1 Tools Required for
Installing and Servicing
R-410A Models
Manifold Sets:
– Up to 800 PSIG [5,516 kPa] High-Side
– Up to 250 PSIG [1,724 kPa] Low-Side
– 550 PSIG [3,792 kPa] Low-Side Retard
Manifold Hoses:
– Service Pressure Rating of 800 PSIG [5,516 kPa]
Recovery Cylinders:
– 400 PSIG [2,758 kPa] Pressure Rating
– Dept. of Transportation 4BA400 or BW400
CAUTION: R-410A systems operate
at higher pressures than R-22 systems. Do not use
R-22 service equipment or components on R-410A
equipment.
4.1.2 Specifications of R-410A
Application: R-410A is not a drop-in
replacement for R-22. Equipment designs must
accommodate its higher pressures. It cannot be
retrofitted into R-22 heat pumps.
Physical Properties: R-410A has an atmospheric
boiling point of -62.9°F [-52.7°C] and its saturation
pressure at 77°F [25°C] is 224.5 psig [1,548 kPa].
Composition: R-410A is a near-azeotropic
mixture of 50% by weight difluoromethane (HFC-
32) and 50% by weight pentafluoroethane (HFC-
125).
Pressure: The pressure of R-410A is
approximately 60% (1.6 times) greater than
R-22. Recovery and recycle equipment, pumps,
hoses, and the like must have design pressure
ratings appropriate for R-410A. Manifold sets need
to range up to 800 psig [5,516 kPa] high-side and
250 psig [1,724 kPa] low-side with a 550 psig
[3,792 kPa] low-side retard. Hoses need to have
a service pressure rating of 800 psig [5,516 kPa].
Recovery cylinders need to have a 400 psig [2,758
kPa] service pressure rating, DOT 4BA400 or DOT
BW400.
Combustibility: At pressures above 1
atmosphere, a mixture of R-410A and air can
become combustible. R-410A and air should
never be mixed in tanks or supply lines or
be allowed to accumulate in storage tanks.
Leak checking should never be done with a
mixture of R-410A and air. Leak-checking can
be performed safely with nitrogen or a mixture of
R-410A and nitrogen.
4.1.3 Quick-Reference Guide
for R-410A
• R-410A refrigerant operates at approximately
60% higher pressure (1.6 times) than R-22.
Ensure that servicing equipment is designed to
operate with R-410A.
• R-410A refrigerant cylinders are light rose in
color.
• R-410A, as with other HFCs, is only compatible
with POE oils.
• Vacuum pumps will not remove moisture from
POE oil used in R-410A systems.
• R-410A systems are to be charged with liquid
refrigerants. Prior to March 1999, R-410A
refrigerant cylinders had a dip tube. These
cylinders should be kept upright for equipment
charging. Post-March 1999 cylinders do not have
a dip tube and should be inverted to ensure liquid
charging of the equipment.
• Do not install a suction line filter drier in the liquid
line.
• A factory-approved bi-flow liquid line filter drier
is shipped with every unit and must be installed
in the liquid line at the time of installation. Only
manufacturer-approved liquid line filter driers
should be used. Filter driers must have a working
pressure rating of at least 600 psig [4,137 kPa].
The filter drier will only have adequate moisture-
holding capacity if the system is properly evacuated.
• Desiccant (drying agent) must be compatible for
POE oils and R-410A refrigerant.
Ambient and Tube
Thermometers
Manifold
Gauge
Set
Brazing
Rods
Torch Nitrogen
Reclaimer
Recovery
Cylinders
Allen Wrench
Crescent Wrench

8
4.0 INSTALLATION
4.2 Choosing a Location
4.2.1 Allowable Clearances
12" to side intake louvers
24" to service access panels
60" vertical for fan discharge
If space limitations exist, the following clearances
will have minimal impact to capacity and efficiency
and are permitted:
Single-Unit Applications: Minimum of 6" to side
intake louvers. DO NOT reduce the 60" [152.4
cm] for fan discharge or the 24" [61.0 cm] service
clearances.
Multiple-Unit Applications: For units positioned
next to each other, a minimum of 6" [15.2 cm]
clearance between units is recommended for 2 ton
models and 9" [22.9 cm] for 3 ton to 5 ton models.
Do not reduce the 60" [152.4 cm] for fan discharge
or the 24" [61.0 cm] service clearances.
IMPORTANT: Consult local and
national building codes and ordinances for special
installation requirements. Following location
information will provide longer life and simplified
servicing of the outdoor heat pump.
NOTICE: These units must be installed
outdoors. No ductwork can be attached, or other
modifications made, to the discharge grille.
Modifications will affect performance or operation.
4.2.2 Operational Issues
Related to Unit Location
IMPORTANT: Locate the unit in a
manner that will not prevent, impair, or compromise
the performance of other equipment installed
in proximity to the unit. Maintain all required
minimum distances to gas and electric meters,
dryer vents, and exhaust and inlet openings. In
the absence of national codes or manufacturers’
recommendations, local code recommendations
and requirements will take precedence.
• Refrigerant piping and wiring should be properly
sized and kept as short as possible to avoid
capacity losses and increased operating costs.
• Locate the unit where water runoff will not create
a problem with the equipment. Position the unit
away from the drip edge of the roof whenever
possible. Units are weatherized, but can be
affected by the following:
• Water pouring into the unit from the junction
of rooflines, without protective guttering. Large
volumes of water entering the heat pump while
in operation can impact fan blade or motor life,
and coil damage may occur to a heat pump if
moisture cannot drain from the unit under freezing
conditions.
• Freezing moisture or sleeting conditions can
cause the cabinet to ice-over prematurely and
prevent heat pump operation, requiring backup
heat, which generally results in less economical
operation It is highly recommended to switch
the Digital Control Center or thermostat to the
"Emergency Heat" mode during freezing rain
or sleeting conditions to prevent damage to the
outdoor coil from ice accumulating on the fan
blade.
• Closely follow the clearance recommendations in
section 4.2.1.
• 24" [61.0 cm] to the service panel access.
• 60" [152.4 cm] above the fan discharge (unit
top) to prevent recirculation.
• 6" [15.2 cm] to the coil grille air inlets
with 12" [30.5 cm] minimum recommended.
Location
SERVICE PANELS/
INLET CONNECTIONS
/ HIGH & LOW
VOLTAGE ACCESS
ALLOW 24” [610 mm] OF
CLEARANCE
ALLOW 60” [1524 mm]
OF CLEARANCE
AIR INLET LOUVERS ALLOW
6” [152 mm] Min. OF
CLEARANCE ALL SIDES
12” [305 mm] RECOMMENDED
ST-A1226-04-00
6" MIN. (152 mm) FOR 1.5 & 2 TON
9" MIN. (229 mm) FOR 2.5-5 TON
24" MIN. (610 mm)

9
Location
4.0 INSTALLATION
4.2 Choosing a Location (cont.)
4.2.3 Corrosive Environment
The metal parts of this unit may be subject to
rust or deterioration if exposed to a corrosive
environment. This oxidation could shorten the
equipment’s useful life.
Corrosive elements include, but are not limited to,
salt spray, fog or mist in seacoast areas, sulphur or
chlorine from lawn watering systems, and various
chemical contaminants from industries such as
paper mills and petroleum refineries.
If the unit is to be installed in an area where
contaminants are likely to be a problem, special
attention should be given to the equipment location
and exposure.
• Avoid having lawn sprinkler heads spray directly
on the unit cabinet.
• In coastal areas, locate the unit on the side of the
building away from the waterfront.
• Shielding provided by a fence or shrubs may give
some protection, but cannot violate minimum
airflow and service access clearances.
WARNING: Disconnect all power
to unit before starting maintenance. Failure to do
so can cause electrical shock resulting in severe
personal injury or death.
Regular maintenance will reduce the buildup of
contaminants and help to protect the unit’s finish.
• Frequent washing of the cabinet, fan blade, and
coil with fresh water will remove most of the salt
or other contaminants that build up on the unit.
• Regular cleaning and waxing of the cabinet
with a good automobile polish will provide some
protection.
• A good liquid cleaner may be used several times
a year to remove matter that will not wash off with
water.
4.2.4 Customer Satisfaction
Issues
• The heat pump should be located away from the
living, sleeping, and recreational spaces of the
owner and those spaces on adjoining property.
• To prevent noise transmission, the mounting pad
for the outdoor unit should not be connected to
the structure and should be located a sufficient
distance above grade to prevent ground water
from entering the unit.
4.3 Unit Mounting
4.3.1 Unit Mounting Methods
The outdoor heat pump unit may be mounted in
a number of ways. The most common method
is on the ground mounted on a concrete or pre-
fabricated pad. It can also be mounted on a ground
or roof mounted metal frame, wooden frame, or 4”
x 4” wooden stringers. It is extremely important to
properly secure the unit to the pad or frame so it
does not shift during high winds, seismic events,
or other outside forces to eliminate the possibility
of a safety hazard or physical damage to the
unit. Local codes in regions subject to frequent
hurricanes and seismic events will dictate specific
mounting requirements and must be followed. It is
also important to elevate the heat pump in areas
that receive a significant amount of snowfall so
accumulated snow does not block the outdoor
coil and interfere with drainage of water during
the defrost cycle. Refer to Section 4.3.4 for typical
ground snow levels for different regions of the
USA.
4.3.2 High Wind and Seismic
Tie-Down Methods
The manufacturer-approved/recommended method
is a guide to securing equipment for wind and
seismic loads. Other methods might provide the
same result, but the manufacturer method is
the only one endorsed by the manufacturer for
securing equipment where wind or earthquake
damage can occur. Additional information is
available in the Product Technical Support section
of the manufacturer’s Web site. If you do not
have access to this site, your distributor can offer
assistance.

10
Location
4.0 INSTALLATION
4.3.4 Ground Snow Depth Table
NOTICE: Local records and experience must be considered when establishing the unit installation height. There is a 2% probability that
the ground snow depth shown in this table will be exceeded annually. Drifts have not been considered. This data represents 184
National Weather Service locations at which measurements are made and assumes a nationwide snow density of 12 lb./ft.
3
A
LABAMA INDIANA MINNESOTA NEW MEXICO PENNSYLVANIA VIRGINIA
Huntsville 7 Evansville 12 Duluth 64 Albuquerque 4 Allentown 23 Dulles Airport 19
A
RIZONA Fort Wayne 17 International Falls 43 Clayton 10 Erie 19 Lynchburg 16
Flagstaff 48 Indianapolis 21
Minneapolis/St. Paul 50 Roswell 8 Harrisburg 23 National Airport 18
Prescott 3 South Bend 44 Rochester 50 NEW YORK Philadelphia 16 Norfolk 9
Winslow 7 IOWA St. Cloud 53 Albany 25 Pittsburgh 22 Richmond 12
A
RKANSAS Burlington 17 MISSISSIPPI Binghamton 35 Scranton 16 Roanoke 17
Fort Smith 5 Des Moines 22 Jackson 3 Buffalo 42 Williamsport 20 WASHINGTON
Little Rock 6 Dubuque 38 MISSOURI
NYC – Kennedy Airport RHODE ISLAND Olympia 24
CALIFORNIA Sioux City 33 Columbia 21
NYC – LaGuardia Airport Providence 21 Quillayute 24
Blue Canyon 25 Waterloo 36 Kansas City 18 Rochester 38 SOUTH CAROLINA Seattle-Tacoma 14
Mt. Shasta 69 KANSAS St. Louis 16 Syracuse 35 Columbia 12 Spokane 41
COLORADO Concordia 23 Springeld 14 NORTH CAROLINA Greenville 4 Stampede Pass 51
Alamosa 15 Dodge City 12 MONTANA Asheville 12 SOUTH DAKOTA Yakima 25
Colorado Springs 14 Goodland 14 Billings 17 Cape Hattaras 5 Aberdeen 42 WEST VIRGINIA
Denver 15 Topeka 19 Glasgow 17 Charlotte 10 Huron 43 Beckley 51
Grand Junction 16 Wichita 11 Great Falls 16 Greensboro 11 Rapid City 14 Charleston 20
Pueblo 7 KENTUCKY Havre 24 Raleigh-Durham 10 Sioux Falls 38 Elkins 21
CONNECTICUT Covington 12 Helena 18 Wilmington 9 TENNESSEE Huntington 15
Bridgeport 23 Lexington 12 Kalispell 53 Winston-Salem 17 Bristol 8 WISCONSIN
Hartford 29 Louisville 11 Missoula 23 NORTH DAKOTA Chattanooga 6 Green Bay 36
New Haven 15 MAINE NEBRASKA Bismarck 25 Knoxville 8 La Crosse 32
DELAWARE Caribou 100 Grand Island 30 Fargo 34 Memphis 5 Madison 32
Wilmington 13 Portland 62 Lincoln 20 Williston 25 Nashville 8 Milwaukee 32
GEORGIA MARYLAND Norfolk 29 OHIO TEXAS WYOMING
Athens 5 Baltimore 17 North Platte 15 Akron-Canton 15 Abilene 6 Casper 10
Macon 8MASSACHUSETTS Omaha 20 Cleveland 16 Amarillo 10 Cheyenne 15
IDAHO Boston 30 Scottsbluff 11 Columbus 10 Dallas 3 Lander 20
Boise 6 Nantucket 18 Valentine 22 Dayton 11 El Paso 5 Sheridan 25
Lewiston 9 Worcester 35 NEVADA Manseld 17 Fort Worth 6
Pocatello 7 MICHIGAN Elko 20 Toledo Express 8 Lubbock 10
ILLINOIS Alpena 53 Ely 9 Youngstown 12 Midland 2
Chicago O’Hare 18 Detroit City 9 Reno 11 OKLAHOMA San Antonio 3
Chicago 22 Detroit Airport 17 Winnemucca 6 Oklahoma City 5 Wichita Falls 5
Moline 17
Detroit – Willow Run 21 NEW HAMPSHIRE Tulsa 8 UTAH
Peoria 16 Flint 28 Concord 66 OREGON Milford 16
Rockford 25 Grand Rapids 37 NEW JERSEY Burns City 24 Salt Lake City 8
Springeld 23 Houghton Lake 56 Atlantic City 11 Eugene 17 Wendover 3
Lansing 42 Newark 15 Medford 8 VERMONT
Marquette 53 Pendleton 11 Burlington 37
Muskegon 43 Portland 10
Sault Ste. Marie 80 Salem 7
18
18
GROUND SNOW DEPTH – INCHES
4.3.3 Elevating Unit
WARNING: Secure an elevated unit and
its elevating stand in order to prevent tipping. Failure to
do so may result in severe personal injury or death.
If elevating the heat pump, either on a flat roof or on a
slab, observe the following guidelines.
• If elevating a unit on a flat roof, use 4" x 4"
[10.2 cm x 10.2 cm] or equivalent stringers positioned
to distribute unit weight evenly and prevent noise and
vibration.
• Where snowfall is anticipated, raise the unit above
the base pad to prevent ice buildup and coil damage.
Mount the unit high enough to be above the average
accumulated area snowfall. See “Ground Snow Depth”
chart below for representative snow depths.
NOTICE: Do not block drain openings on
bottom of unit.
• If unit must be elevated because of anticipated
snowfall, secure unit and elevating stand such that
unit and/or stand will not tip over or fall off. Keep in
mind that someone may try to climb on unit.
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11
4.0 INSTALLATION
4.4 Refrigerant Line Set Selection
4.4.1 Replacing Existing
Systems
To prevent failure of a new unit, the existing line set
must be correctly sized for the new unit and must
be cleaned or replaced. Care must be taken so
the expansion device is not plugged. For new and
replacement units, a liquid line filter drier must be
installed and the line set must be properly sized.
Test the oil for acid. If it tests positive for acid, a
suction line filter drier is mandatory.
IMPORTANT: When replacing an
R-22 unit with an R-410A unit, either replace
the line set or ensure that residual mineral oil is
drained from existing lines including oil trapped in
low spots.
4.4.2 Line Set Application
Considerations
The following are special considerations that need
to be addressed when selecting and installing a line
set.
• Additional refrigerant charge
• Fitting losses and maximum equivalent length
considerations
• Refrigerant migration during the off cycle
• Oil return to the compressor
• Capacity losses
• System oil level adjustment
4.4.2.1 Oil Return to Compressor
Small amounts of compressor crankcase oil is
picked up and carried out of the compressor by the
moving refrigerant and is circulated through the
system along with the refrigerant before it returns to
the compressor crankcase. It is critical to the life of
the compressor for the oil to be able to return to the
compressor to maintain an adequate level of oil in
the compressor crankcase. Oversized vapor lines
result in inadequate refrigerant velocities to carry
the oil along with the refrigerant and will cause the
oil to accumulate in the low spots in the vapor line
instead of being returned to the compressor crank-
case. This is especially true for long line lengths.
Variable speed systems present an additional chal-
lenge due to the fact that the system operates at
ASIGNIkCANTLYREDUCEDREFRIGERANTlOWRATEFORASIG-
NIkCANTPERCENTAGEOFOPERATINGTIME/NLYUSETHE
vapor line sizes listed in Table 2 to assure proper
oil return. DO NOT oversize vapor line!
4.4.2.2 Refrigerant Migration Dur-
ing Off Cycle
Long line set applications can require a consider-
able amount of additional refrigerant. This addition-
al refrigerant needs to be managed throughout the
entire ambient operating envelope that the sys-
tem will go through during its life cycle. Off-Cycle
migration is where excess refrigerant condenses
and migrates to the coldest and/or lowest part of
the system. Excessive build-up of refrigerant at the
compressor will result in poor reliability and noisy
operation during startup. Section 4.5.2 demon-
STRATESTHEREQUIREDUNITCONkGURATIONFORDIFFERENT
applications.
The outdoor unit controls can energize a portion
of the compressor motor stator as needed during
the off cycle to prevent liquid refrigerant from ac-
cumulating inside the compressor, similar to how a
crankcase heater functions on conventional sys-
tems.
4.4.2.3 Maximum Liquid Pressure
Drop
The total liquid line pressure drop must not exceed
50 psig [345 kPa] to assure a solid column of liquid
at the metering device and stable control of super-
heat. Be sure to account for vertical separation,
ELBOWSkLTERDRIERSSOLENOIDVALVESSIGHTGLASSES
and check valves when calculating liquid line pres-
sure drop.
4.4.2.4 Liquid Line Refrigerant
Flashing
Excessive pressure drop and heat gain in long liq-
UIDLINESCANRESULTINTHEREFRIGERANTlASHINGINTOA
vapor before it reaches the expansion device which
WILLDRAMATICALLYREDUCETHECAPACITYANDEFkCIENCY
of the system. For this reason, the liquid line must
be sized properly using Table 2 and must be insu-
lated in unconditioned spaces.
Tubing

12
Tubing
4.0 INSTALLATION
4.4.2.5 Oil Level Adjustment for
Long Line Set Applications
Additional oil will need to be added if refrigerant is
added during installation. The following provides
the equation for the oil level adjustment and the
compressor name plate oil charge for the different
outdoor units.
Oil to be Added = [(Charge Adjustment + OD
Unit Name Plate Refrigerant Charge (oz.)) ×
(0.022) – [(0.10) × (Compressor Name Plate Oil
Charge (oz.))]
Example: An application requires 125 ft of line set
with a liquid line diameter of 3/8”, Charge Adjust-
ment = 66 oz., Name Plate Charge = 212 oz.,
Name Plate Oil Charge = 40 oz., Oil to be Added =
((66 oz. + 212 oz.) × .022) – (.10 × 40 oz.) = 2 oz.
4.4.2.6 Capacity Losses
Long line lengths can result in a reduction in capac-
ity due to vapor line pressure drop and heat gain or
loss. Refer to Table 2 for capacity loss multipliers
for various vapor line diameters and equipment line
lengths. This table does not account for any capac-
ity loss due to heat gain or loss from the environ-
ment. It is extremely important not to oversize the
vapor line to minimize capacity loss at the expense
of proper oil return. If the table shows an “NR” for
a particular vapor line diameter and length, or, if a
vapor line diameter is not listed, oil return will not be
adequate.
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ϱϴ΀ϭϱϴϴ΁ ϭϱ΀Ϭϰϲ΁ ϭ΀ϬϯϬ΁ Ϭϱ΀Ϭϭϱ΁ ϭϮ΀ϯϲϲ΁ ϲ΀ϭϴϯ΁ Ϭϴ΀ϬϮϰ΁ ϲ΀ϭϴϯ΁
ϯϰ΀ϭϵϬϱ΁ ϭϵ΀Ϭϱϴ΁ ϭϯ΀ϬϰϬ΁ Ϭϲ΀Ϭϭϴ΁ ϭϰ΀ϰϮϳ΁ ϳ΀Ϯϭϯ΁ Ϭϵ΀ϬϮϳ΁ ϲ΀ϭϴϯ΁
ϳϴ΀ϮϮϮϯ΁ Ϯϯ΀ϬϳϬ΁ ϭϱ΀Ϭϰϲ΁ Ϭϳ΀ϬϮϭ΁ ϭϱ΀ϰϱϳ΁ ϴ΀Ϯϰϰ΁ ϭ΀ϬϯϬ΁ ϲ΀ϭϴϯ΁
ϭͲϭϴ΀Ϯϴϱϴ΁ Ϯϳ΀ϬϴϮ΁ ϭϴ΀Ϭϱϱ΁ Ϭϵ΀ϬϮϳ΁ ϮϮ΀ϲϳϭ΁ ϭϮ΀ϯϲϲ΁ ϭϱ΀Ϭϰϲ΁ ϲ΀ϭϴϯ΁
Table 1
Refrigerant tubing is measured in terms of actual
length and equivalent length. Actual length is used
for refrigerant charge applications. Equivalent
length takes into account pressure losses from tub-
INGLENGTHkTTINGSVERTICALSEPARATIONACCESSORIES
ANDkLTERDRIERS4HETABLEBELOWREFERENCESDIFFER-
ent commonly used equivalent lengths.
4.4.3 Line Set Length and Fitting Losses

13
4.0 INSTALLATION
4.4.5 Vapor Line Selection
The purpose of the vapor line is to return superheat-
ed vapor to the condensing unit from the indoor coil
in the cooling mode. While in the heating mode, the
vapor line transports discharge vapor to the indoor
coil from the outdoor unit. Proper vapor line sizing
is important because it plays an important role in
returning oil to the compressor to prevent potential
damage to the bearings, valves, and scroll sets.
Also, an improperly sized vapor line can dramatical-
ly reduce capacity and performance of the system.
The procedure for selecting the proper vapor line is
as follows:
• Determine the total linear length of vapor line
required.
• Add all of the equivalent lengths associated with
ANYkTTINGSORACCESSORIESUSING4ABLE
r !DDTHELINEARLENGTHANDTOTALkTTINGEQUIVALENT
length. This will equal your total equivalent line
length.
• Reference Table 2 to verify that the calculated
equivalent length falls within the compatibility
region of the chart.
• Verify capacity loss is acceptable for the applica-
tion.
Tubing
4.4.4 Liquid Line Selection
The purpose of the liquid line is to transport warm
sub-cooled liquid refrigerant between the outdoor unit
to the indoor unit in the cooling mode. In the heating
mode, the liquid line returns sub-cooled liquid from
the indoor unit to the outdoor unit. It is important not
TOALLOWTHEREFRIGERANTTOlASHINTOSUPERHEATEDVAPOR
prior to entering the expansion device of the indoor
coil or outdoor unit. Flashing of refrigerant can occur
for the following reasons:
• Low refrigerant charge
• Improperly selected liquid line size
• Absorption of heat prior to expansion device
• Excessive vertical separation between the outdoor
unit and indoor coil
r 2ESTRICTEDLIQUIDLINEARkLTERDRIER
• Kinked liquid line
The total pressure drop allowed for the liquid line is 50
PSI [345 kPa]. The procedure for selecting the proper
liquid line is as follows:
• Measure the total amount of vertical separation
between the outdoor unit and indoor coil.
• Measure the total indoor length of liquid line re-
quired.
• Add all of the equivalent lengths associated with
ANYkTTINGSORACCESSORIESUSING4ABLE
r !DDTHELINEARLENGTHTOTHETOTALkTTINGEQUIVALENT
length. This will equal your total equivalent line
length.
• Reference Table 2 to verify the calculated equiva-
lent length is acceptable with the required vertical
separation and diameter of liquid line.
Example: A 3-ton heat pump unit is installed 25’
below the indoor unit, requires a 75’ of 1/2” diameter
liquid line, 3/4" vapor line, 4 90° LR elbows, and a
kLTERDRIER
• Fitting Equivalent Length (ft.) = (4 x .9') + 6' = 84.6'
• Total Equivalent Length (ft.) = 75' + 9.6' = 84.6'
This application is acceptable because the 25’ vertical
rise is less than the maximum rise of 50’ for this ap-
plication.
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14
4.0 INSTALLATION
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'
4*!#!$'
5*##!/'8//'85!
%!'
6*#" '
4
**See
Note 4
1'/
+
/
2
3
$#!#!!#
'$!#!#+#($#!
.*!!#)!#,"#"-
 $%##,#-
1/
#)
&
 $
)
&
!
)

15
4.0 INSTALLATION
<: :+37 38+45 46+52 53+5:5;+68
8)57-3*6.37)::-7*:. :*3)22 37*2);; 32*2);: 4*2);9 
9);6-7*38.37)::-7*:. :*3)22 37*2);; 37*2);: 37*2);9 37*2);8 37*2);7
;)75-5*:. 37)::-7*:. :*3)22 37*2);; 37*2);: 37*2);9 37*2);8 37*2);7
8)57-3*6.3;)27-5*6./:*3)22 37*2);; 32*2);; 4*2);;  
9);6-7*38.3;)27-5*6./:*3)22 37*2);; 37*2);; 37*2);; 37*2);; 37*2);:
;)75-5*:. 3;)27-5*6./:*3)22 37*2);; 37*2);; 37*2);; 37*2);; 37*2);:
9);6-7*38.37)::-7*:. :*2);; 37*2);9 37*2);7 37*2);5 33*2);3
;)75-5*:. 37)::-7*:. :*2);; 37*2);9 37*2);7 37*2);5 37*2);3
9);6-7*38.3;)27-5*6.:*3)22 37*2);; 37*2);; 37*2);: 33*2);98*2);8
;)75-5*:. 3;)27-5*6.:*3)22 37*2);; 37*2);; 37*2);: 37*2);9 37*2);8
34)9-3*4.3;)27-5*6.:*3)22 37*2);; 37*2);; 37*2);: 37*2);9 37*2);8
;)75-5*:. 3;)27-5*6.:*2);; 37*2);: 37*2);8 37*2);7 37*2);5 37*2);4
34)9-3*4.3;)27-5*6.:*2);; 37*2);: 37*2);8 37*2);7 37*2);5 37*2);4
;)75-5*:. 44)45-9*:. :*3)22 37*2);; 37*2);; 37*2);: 37*2);: 37*2);9
34)9-3*4.44)45-9*:. :*3)22 37*2);; 37*2);; 37*2);: 37*2);: 37*2);9
;)75-5*:. 3;)27-5*6.:*2);: 37*2);9 37*2);7 37*2);5 36*2);3
34)9-3*4.3;)27-5*6.:*2);: 37*2);9 37*2);7 37*2);5 37*2);3
;)75-5*:. 44)45-9*:. :*2);; 37*2);; 37*2);: 37*2);9 37*2);8 34*2);7
34)9-3*4.44)45-9*:. :*2);; 37*2);; 37*2);: 37*2);9 37*2);837*2);7
;)75-5*:. 4:)7:-3+3*:.// :*3)22 37*3)22 37*3)22 37*2);; 37*2);; 34*2);;
34)9-3*4.4:)7:-3+3*:.// :*3)22 37*3)22 37*3)22 37*2);; 37*2);; 37*2);;
 (
3, $68  )
4, $37 "   #! ! )
5,/3;)27-5*6)."!%!4 % ! ! # "
!  ! !)
6,//4:)7:-3+3*:)."!%!7 % ! ! # "
!  ! !)
7,#%!  !# & )
8,  %  %!  #2);22);8# 
'! #)
9, % ! $"!! !)
39)8
[5 Ton]
** See
Note 4
9)2
-4)2.
/
1
32)8
-5.
36)3
-6.
0)  "( "," "!-
42 !
"(
%
#
(
.*/
% 
(
.*/
#" "  "
#$""," !-
&# " "+"'#"

16
4.0 INSTALLATION
Tubing
• If tubing is to be run underground, it must be run in
a sealed watertight chase.
• Use care in routing tubing and do not kink or twist.
Use a good quality tubing bender on the vapor line
to prevent kinking.
• Route the tubing using temporary hangers; then
straighten the tubing and install permanent hangers.
The tubing must be adequately supported.
• Isolate the vapor line from the building structure. If
the vapor line comes in contact with inside walls,
ceiling, or flooring, the vibration of the vapor line
in the heating mode will result in noise inside the
structure.
• Blow out the liquid and vapor lines with dry nitrogen
before connecting to the outdoor unit and indoor
coil to remove debris that can plug the expansion
device.
TEMPORARY
HANGER PERMANENT
HANGER
ST-A1226-05-00
Observe the following when installing correctly
sized type “L” refrigerant tubing between the
outdoor unit and indoor coil:
• Check Table 2 for the correct vapor line size and
liquid line size.
• If a portion of the liquid line passes through a
very hot area where liquid refrigerant can be
heated to form vapor, insulating the liquid line
is required.
• Use clean, dehydrated, sealed refrigeration-grade
tubing.
• Always keep tubing sealed until tubing is in place
and connections are to be made.
• A high-quality biflow filter drier is included with all
R-410A heat pump units and must be installed in
the liquid line upon unit installation.
• When replacing an R-22 system with an R-410A
system and the line set is not replaced, blow out
the lines with dry nitrogen to remove as much
of the remaining mineral oil as possible. Check
for low spots where oil may be trapped and take
measures to drain the oil from those areas.
• If tubing has been cut, debur the ends while
holding the tubing in a position to prevent chips
from falling into tubing. Burrs such as those
caused by tubing cutters can affect performance
dramatically, particularly on small diameter liquid
lines.
• For best operation, keep tubing run as short as
possible with a minimum number of elbows or
bends.
• Locations where the tubing will be exposed to
mechanical damage should be avoided. If it is
necessary to use such locations, the copper
tubing should be protected by a housing to
prevent damage.
4.5 Line Set Installation
4.5.1 Important Tubing Installation Practices

17
Tubing
4.5 Line Set Installation (cont.)
4.0 INSTALLATION
4.5.2 Relative Location of Indoor and Outdoor Units
4.5.2.1 Outdoor Unit Level or Near Level to Indoor Coil Line Set
ST-A1219-01-01
REFERENCE TABLE 2 FOR
MAXIMUM LENGTH LIMITATIONS
IDEALLY, LINE SET SLOPES AWAY
FROM OUTDOOR UNIT. VERIFY
SUB-COOLING PRIOR TO EXPANSION
DEVICE, INSULATED LIQUID LINE IN
UNCONDITIONED SPACE FOR
LONG LINE APPLICATIONS.
INSULATED VAPOR LINE FULL LENGTH
Figure 3
For applications with the outdoor unit and indoor
unit on the same level the following is required:
• Insulated liquid line in unconditioned space only.
• Insulated vapor line full length.
• Vapor line should slope toward the indoor unit.
(Reference Figure 3)
• Follow the proper line sizing, maximum linear
and equivalent length, charging requirements,
and oil level adjustments spelled out in this docu-
ment.
• Verify at least 5°F [2.8°C] sub-cooling at the
indoor unit prior to expansion device.

18
4.0 INSTALLATION
For applications with the outdoor unit below the
indoor coil, the following is required:
• Inverted vapor-line trap (Reference Figure 4)
• Insulated liquid line in unconditioned space only.
• Insulated vapor line full length.
• Follow the proper line sizing, maximum linear
and equivalent length, maximum vertical separa-
tion, charging requirements, and oil level adjust-
ments spelled out in this document.
• Measure pressure at the liquid line service valve
and prior to expansion device. Verify that the
pressure drop is not greater than 50 PSI [345
kPa].
• For elevations greater that 25’ [8 m] a lower sub-
cooling can be expected.
• Verify there is at least 5ºF [2.8ºC] of liquid sub-
cooling at the indoor coil prior to the expansion
device.
Tubing
4.5.2.2 Outdoor Unit Below Indoor Coil (Long Line Set Applications)
Figure 4
INVERTED TRAP
EVEN WITH TOP
OF THE COIL
REFERENCE TABLE 2 FOR
MAXIMUM LENGTH AND
VERTICAL SEPARATION LIMITATIONS
ST-A1219-02-01
INSULATE LIQUID LINE
IN UNCONDITIONED
SPACE FOR LONG
LINE APPLICATIONS
INSULATED VAPOR LINE FULL LENGTH
VERIFY LIQUID SUBCOOLING
PRIOR TO EXPANSION DEVICE
IN THE COOLING MODE.

19
Tubing
4.0 INSTALLATION
For applications with the outdoor unit above the
indoor coil the following is required:
• Insulated liquid line in unconditioned space only.
• Follow the proper line sizing, maximum linear and
equivalent length, maximum vertical separation,
charging requirements, and oil level adjustments
spelled out in this document.
• Insulated vapor line full length.
• Verify at least 5°F [2.8ºC] of liquid subcooling at
the outdoor unit prior to expansion device in the
heating mode.
4.5.2.3 Outdoor Unit Above Indoor Coil
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Figure 5

20
Tubing
4.5.3 Tubing Connections
Indoor coils have only a holding charge of
dry nitrogen. Keep all tube ends sealed until
connections are to be made.
• Use type “L” copper refrigeration tubing. Braze
the connections with the following alloys:
– Copper to copper, 5% silver minimum
– Copper to steel or brass, 15% silver minimum
• Be certain both refrigerant shutoff valves at the
outdoor unit are closed.
• Remove the caps and Schrader cores from the
pressure ports to protect seals from heat damage.
Both the Schrader valves and the service valves
have seals that may be damaged by excessive heat.
• Clean the inside of the fittings and outside of the
tubing with a clean, dry cloth before soldering. Clean
out debris, chips, dirt, etc., that enters tubing or
service valve connections.
• Wrap valves with a wet rag or thermal barrier
compound before applying heat.
• Braze the tubing between the outdoor unit and
indoor coil. Flow dry nitrogen into a pressure port
and through the tubing while brazing, but do not
allow pressure inside tubing which can result in
leaks. Once the system is full of nitrogen, the
nitrogen regulator should be turned off to avoid
pressuring the system.
• A fter brazing, use an appropriate heatsink material
to cool the joint.
• Reinstall the Schrader cores into both pressure
ports.
• Do not allow the bare vapor line and liquid line
to be in contact with each other. This causes an
undesirable heat transfer resulting in capacity
loss and increased power consumption.
4.0 INSTALLATION