Carrier 25VNA User Manual

Installation Instructions

NOTE: Read the entire instruction manual before starting the installation,

TABLE OF CONTENTS

SAFETY CONSIDERATIONS ................................................................... 2

INSTALLATION RECOMMENDATIONS ........................................................ 3

INSTALLATION ........................................................................... 3-11

Step 1 -- Check Equipment and Jobsite ........................................................... 4

2 -- Install on Solid Pad ................................................................... 4

Step
Step

3 -- Clearance Requirements ............................................................... 4

Step

4 -- Operating Ambient ................................................................... 4

5 -- Elevate Unit ........................................................................ 4

Step
Step

6 -- Liquid Line Solenoid Valve (LSV) ....................................................... 4

Step

7 -- Making Piping Connections .......................................................... 5-6

8 -- Make Electrical Connections ........................................................... 7

Step
Step

9 -- Compressor Crankcase Heater .......................................................... 7

10 -- Install Accessories ................................................................... 8

Step
Step

11 -- Start-Up .......................................................................... 8

Step

12 -- System Functions and Sequence of Operation ........................................... 8-10

Step

13 -- Check Charge ................................................................... 10-11

Step

14 -- Pumpdown 8: Evacuation ............................................................ 11

PAGE NO.

MAJOR COMPONENTS .......................................................................... 12

TROUBLESHOOTING .......................................................................... 12-16

FINAL CHECKS ................................................................................. 18

CARE AND MAINTENANCE ...................................................................... 18

PURON ® REFRIGERANT QUICK REFERENCE GUIDE .............................................. 18

Information in these installation instructions pertains only to
25VNA series units.

SAFETY CONSIDERATIONS

Improper installation, adjustment, alteration, service, maintenance,
or use can cause explosion, fire, electrical shock, or other

conditions which may cause death, personal injury, or property
damage. Consult a qualified installer, service agency, or your
distributor or branch for information or assistance. The qualified

installer or agency nmst use factory-authorized kits or accessories
when modifying this product. Refer to the individual instructions

packaged with the kits or accessories when installing.
Follow all safety codes. Wear safety glasses, protective clothing,

and work gloves. Use quenching cloth for brazing operations.
Have fire extinguisher available. Read these instructions

thoroughly and follow all warnings or cautions included in
literature and attached to the unit. Consult local building codes and

current editions of the National Electrical Code ( NEC ) NFPA 70.
In Canada, refer to current editions of the Canadian electrical code

CSA 22.1.

Recognize safety information. This is the safety-alert symbol/}k
When you see this symbol on the unit and in instructions or

manuals, be alert to the potential for personal injury. Understand
these signal words; DANGER, WARNING, and CAUTION. These

words are used with the safety-alert symbol. DANGER identifies
the most serious hazards which will result in severe personal injury

or death. WARNING signifies hazards which could result in
personal injury or death. CAUTION is used to identify unsafe

practices which would result in nfinor personal injury or product
and property damage. NOTE is used to highlight suggestions

which will result in enhanced installation, reliability, or operation.

Indoor Thermostat Control Options

Model Infinity

25VNA Yes*

Requires model SYSTXCCUID01-V or SYSTXCCUIZ01-V or newer.

ELECTRICALSHOCK HAZARD
Failure to follow this warning could result in personal

injury or death.
Before installing, modifying, or servicing system, main

electrical disconnect switch nmst be in the OFF position.
There may be more than 1 disconnect switch. Lock out and
tag switch with a suitable warning label.

ELECTRICAL HAZARD - HIGH VOLTAGE!

Failure to follow this warning could result in personal injury
or death.

Electrical components may hold charge. DO NOT remove
control box cover for 2 nfinutes after power has been

removed from unit.
PRIOR TO TOUCHING ELECTRICAL COMPONENTS:

Verify zero (0)voltage at inverter connections shown on
inverter cover.

Control

CUT HAZARD

Failure to follow this caution may result in personal iniury.

Sheet metal parts may have sharp edges or burrs. Use care and
wear appropriate protective clothing and gloves when
handling parts.

Inverter Cover
IMPORTANT: The inverter cover should NEVER be removed

because there is no reason to remove the inverter cover to access
the inverter. The inverter is not serviceable. A replacement cover

is provided with a replacement inverter.

UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could result in personal injury

or equipment damage.
Puron® refrigerant systems operate at higher pressures than

standard R-22 systems. Do not use R-22 service equipment
or components on Puron® refrigerant equipment.

Installation Recommendations

In some cases noise in the living area has been traced to gas
pulsations from improper installation of equipment.

1. Locate unit away from windows, patios, decks, etc. where
unit operation sound may disturb customer.

2. In noise sensitive applications (such as bedrooms), when a
lineset is mounted to ceiling joists or floor joists, the out-

door unit must be located at least 10 ft (3.05 m) away. If
this is not possible, create a line set configuration with

enough bends to provide 10 ft (3.05 m) of total line set
length outside the dwelling

3. Ensure that vapor and liquid tube diameters are appropriate
for unit capacity.

4. Run refrigerant tubes as directly as possible by avoiding un-
necessary turns and bends.

5. Leave some slack between structure and unit to absorb vi-
bration.

6. When passing refrigerant tubes through the wall, seal open-
ing with RTV or other pliable silicon-based caulk (see Fig.

1).

7. Avoid direct tubing contact with water pipes, duct work,
floor joists, wall studs, floors, and walls.

8. Do not suspend refrigerant tubing from joists and studs with
a rigid wire or strap which comes in direct contact with
tubing (see Fig. 1).

9. Ensure that tubing insulation is pliable and completely sur-
rounds vapor tube.

10. When necessary, use hanger straps which are 1 in. wide and
conform to shape of tubing insulation. (See Fig. 1.)

11. Isolate hanger straps from insulation by using metal sleeves
bent to conform to shape of insulation.

EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage.
If proper lineset routing techniques are not followed, variable

speed systems can be susceptible to lineset transmitted noise
inside the dwelling and, in extreme cases, tubing breakage.

Adjust refrigerant charge by adding or removing the charge
to/from the unit depending on lineset length and indoor unit as
calculated and displayed on the UI. The user interface (UI)

calculates required charge adjustment and total system charge
required. For proper unit operation, check refrigerant charge using
charging information in the Check Charge section of this
instruction.

IMPORTANT: Liquid-line size is 3/8-in. OD for all 25VNA

applications including long line applications.

IMPORTANT: Always install the factory-supplied liquid-line
filter drier. Obtain replacement filter driers from your distributor or

branch.

IMPORTANT: Always install the factory-supplied mufi3er (part
#LM10KK003) on the vapor line as described in the Factor)'

Supplied Muffler blstallation section of these instructions.

Obtain replacement mufflers from you distributor or branch.

INSTALLATION

Specifications for this unit in residential new construction market

require the outdoor unit, indoor unit (including metering device),
refrigerant tubing sets, and filter drier, and mufi'ler listed in pre-sale

literature. There can be no deviation. Consult the Service Manual -
Air Conditioners and Heat Pumps Using Puron® Refrigerant to
obtain required unit changes for specific applications and for R-22

retrofit.

Step 1 -- Check Equipment and Job Site

Unpack Unit
Move to final location. Remove carton taking care not to damage

unit.
This unit employs one louver spacer on each of the four sides to

prevent louver movement during operation. The louver spacers are
trapped between the coil surface and louver at the approximate
center of each side (See Fig. 2). This louver spacer should be

present and, if dislodged during shipment, must be reinstalled
before unit is placed into operation.

Louver Spacer

1"/25......../_1I'W _

MiN _'- LiQUiD TUBE

SUSPENSION

A07588

Fig. 1 - Connecting Tubing Installation

The outdoor unit contains the correct amount of refrigerant charge
for operation with AHRI rated and factory-approved smallest

indoor unit when connected by 15 ft (4.57 m) of field-supplied or
factory accessory tubing.

A11380

Fig. 2 - Louver Spacer Location

Inspect Equipment
File claim with shipping company prior to installation if shipment

is damaged or incomplete. Locate unit rating plate on unit corner
panel. It contains information needed to properly install unit,

Check rating plate to be sure unit matches job specifications,

Step 2 -- Install on a Solid, Level Mounting Pad

If conditions or local codes require the unit be attached to pad, tie
down bolts should be used and fastened through knockouts
provided in unit base pan. Refer to unit mounting pattern in Fig. 3

to determine base pan size and knockout hole location.
For hurricane tie downs, contact distributor for details and PE

(Professional Engineer) Certification, if required.
On rooftop applications, mount on level platform or frame. Place

unit above a load-bearing wall and isolate unit and tubing set from
structure. Arrange supporting members to adequately support unit

and minimize transmission of vibration to building. Consult local
codes governing rooftop applications.

Roof mounted units exposed to winds above 5 mph may require
wind baffles. Consult the Service Manual - Residential Split

System Air Conditioners and Heat Pumps Using Puron®
Refrigerant for wind baffle construction.

NOTE: Unit must be level to within ---2° (---3/8 in./ft,--9.5 mm/m.)
per compressor manufacturer specifications.

Step 3 -- Clearance Requirements

When installing, allow sufficient space for airflow clearance,
wiring, refrigerant piping, and service. Allow 24 in. (609.6 mm)

clearance to service end of unit and 48 in. (1219.2 mm) (above
unit. For proper airflow, a 6-in. (152.4 mm) clearance on 1 side of

unit and 12-in. (304.8 mm) on all remaining sides must be
maintained. Maintain a distance of 24 in. (609.6 mm) between
units. Position so water, snow, or ice from roof or eaves cannot fall

directly on unit.
On rooftop applications, locate unit at least 6 in. (152.4 mm) above

roof surface.

3/8-in. (9,53 mm) Dia,
Tiedown Knockouts in

Basepan(2) Places

[]NIT OPERATION HAZARD
Failure to follow this caution may result in equipment

damage or improper operation.
Do not allow water and/or ice to build up in base pan.

[]NIT OPERATION HAZARD
Failure to follow this caution may result in equipment

damage or improper operation.
Locate the unit in such a way that it is stable in all

circumstances including adverse weather conditions.

Step 6 -- In Long-Line Applications, Install
Liquid-Line Solenoid Valve (LSV)

For refrigerant piping arrangements with equivalent lengths of
greater than 80 ft. (24.38 m) and/or when elevation difference

between indoor and outdoor unit is greater than -+20 ft. (-+6.10 m),
follow the piping configuration and liquid line solenoid valve

(LSV) accessory requirements from the Residential Piping and
Long-line guideline. CCH, start gear and piston changes do not

apply. If required by Long-Line Guideline, install LSV kit, part
no. KHALS0401LLS, specifically designed for Puron® refrigerant
heat pumps. LSV should be installed within 2 ft. (0.61 m) of

outdoor unit with flow arrow pointing toward outdoor unit.
Make the necessary electrical connections as shown on Fig. 20 and

by following the Installation Instructions included with accessory
kit.

IMPORTANT: Flow arrow must point toward outdoor unit.

View From Top

A05177

UNIT BASE PAN

Dimension in. (mm)

38X38

(669X88g)

TIEDOWN KNOCKOUT LOCATIONS in. (mm)

A B C

9-1/8 (231.8) 6-9/16 (166.7) 28-7/16 (722.3)

Fig. 3 - Tiedown Knockout Locations

Step 4 -- Operating Ambient

The minimum outdoor operating ambient in cooling mode is 55 °F
(12.78°C) without low ambient cooling enabled, and the

maximum outdoor operating ambient in cooling mode is 125°F
(51.67°C). The maximum heating operation ambient is 66°F

(18.9°C). Compressor protections prevent operation below -10 to

-20°F.

Step 5 -- Elevate Unit

Elevate unit per local climate and code requirements to provide
clearance above estimated snowfall level and ensure adequate
drainage of unit.

Variable

User Interface

A

B

C

D

S1

S2

Furnace or Speed
Fan Coil HP

OpttonN Ren_t e ._.

Fig. 4 - Liquid Line Solenoid Electrical Connection

(Required for long line applications)

LLS

....... 1

__ ]

Al1107

Step 7 -- Make Piping Connections

UNIT DAMAGE HAZARD

PERSONAL INJURY AND UNIT DAMAGE
HAZARD

Failure to follow this warning could result in personal injury or
death.

Relieve pressure and recover all refrigerant before system
repair or final unit disposal. Use all service ports and open all
flow-control devices, including solenoid valves.

UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment

damage or improper operation.
Do not leave system open to atmosphere any longer than

minimum required for installation. POE oil in compressor is
extremely susceptible to moisture absorption. Always keep
ends of tubing sealed during installation.

Table 1 - Refrigerant Connections and Recommended Liquid and Vapor 1hbe Diameters (in.)

LIQUID VAPOR*

UNIT SIZE Connection Tube Connection Max (Rated) Minimum Tube

25VNA024 3/8 3/8 7/8 7/8 5/8

25VNA036 3/8 3/8 7/8 7/8 5/8
25VNA048 3/8 3/8 7/8 1- 1/8 3/4

25VNA060 3/8 3/8 7/8 1- 1/8 3/4

Units are rated with 25 It. (7.6 m) of lineset. See Product Data sheet for performance data when using different size and length line sets.

Notes:

1. Do not apply capillary tube indoor coils to these units.

2. For Tubing Set lengths between 80 and 200 It. (24.38 and 60.96 m) horizontal and / or greater than 20 It. (6.1 m) vertical differential, an accessory Liquid Line
Solenoid must be installed.

Diameter Diameter Diameter Diameter Diameter

Failure to follow this caution may result in equipment
damage or improper operation.

If ANY refrigerant tubing is buried, provide a 6 in. (152.4
ram) vertical rise at service valve. Refrigerant tubing lengths
up to 36 in. (914.4 ram) may be buried without further

special consideration. Do not bury lines longer than 36 in.
(914.4 ram).

Outdoor units may be connected to indoor section using accessory
tubing package or field-supplied refrigerant grade tubing of correct
size and condition. For tubing requirements beyond 80 ft. (24.38

m), substantial capacity and performance losses can occur. Follow
the pipe sizing recommendations in the 25VNA Product data to
manage these losses.

Refer to Table 1 for field tubing diameters. Refer to Table 2 for

accessory requirements.

Table 2 - Accessory Usage

REQUIRED FOR Installations with Radio

ACCESSORY LOW-AMBIENT COOLING APPLICATIONS* COAST APPLICATIONS Frequency Interference

Crankcase Heater Standard Standard Standard Standard

Evaporator Freeze Protection Standard with Infinity TM Control No No No

Liquid-Line Solenoid Valve No Yes No No

Low-Ambient Control Standard with Infinity Control No No No

Puron Refrigerant Balance Port Yes1" Yes]- Yes1" Yes1"

Hard-ShutOff TXV

Support Feet Recommended No Recommended No

Winter Start Control Standard with Infinity Standard with Infinity Standard with Infinity Standard with Infinity

EMI Kit No No No Yes

For tubing set lengths between 80 and 200 It. (24.38 and 60.96 m) horizontal or 20 It. (6.10 m) vertical differential (total equivalent length), an accessory

Liquid Line Solenoid must be installed.
1- Required on all indoor units. Standard on all new Puron refrigerant fan coils and furnace coils.
Standard = Standard for all new Puron refrigerant fan coils and furnace coils.

APPLICATIONS Concerns in the Range

(Below 55°F/12.6°C) (Over 60 ft/24.38 m) (Within 2 miles/3.22 km) of 2 to 30 MHZ

Control Control Control Control

REQUIRED FOR LONG LINE REQUIRED FOR SEA

Outdoor Unit Connected to Factory-Approved Indoor
Unit

Outdoor unit contains correct system refrigerant charge for
operation with factory-approved, AHRI-rated smallest indoor unit

when connected by 15 ft. (4.57 m) of field-supplied or
factory-accessory tubing, and factory-supplied filter drier. Check
refrigerant charge for maximum efficiency.

NOTE: If the indoor furnace coil width is more than the furnace
casing width, refer to the indoor coil Installation Instructions for

transition requirements.

Install Liquid-Line Filter Drier Indoor
Refer to Fig. 6 and install filter drier as follows:

1. Braze 5-in. (127 mm) liquid tube to the indoor coil.

2. Wrap filter drier with damp cloth.

3. Braze filter drier to above 5-in. (127 mm) liquid tube.

4. Connect and braze liquid refrigerant tube to the filter drier.

[]NIT DAMAGE HAZARD

Failure to follow this caution may result in unit damage or
improper operation.

Installation of filter drier in liquid line is required.

A05227

Fig. 6 - Liquid-Line Filter Drier

Refrigerant Tubing connection Outdoor

Connect vapor tube to fitting on outdoor unit vapor service valves

(see Table 1).

NO Installation of Adapter Tube
Although it is a heat pump this unit has a standard AC liquid

service valve. An EXV inside the unit serves as the heating
expansion device.

Sweat Connections

Factory Supplied Muffler (part # LM10KK003)
Installation is Required On Every Installation:

• A muffler is required to reduce noise transmitted to indoor

through the line set.

• Muffler may be installed in the vertical or the horizontal

direction, maintaining at least 12 in. (304.8 mm) straight pipe
length from the OD unit (See Fig. 5).

• Maintain at least 12 in. (304.8 mm) to any bend from the muffler
shell inlet and outlet stubs.

_ XTERIOR

WALL

_8 ram) MiN

VAPOR SERVICE VALVE S (3048 ram) MIN

EXTERIOR
WALL

VAPOR SERVICE VALVE _ (3048 ram) MIN

Fig. 5 - Muffler Installation

--VAPOR LiNE

Al1108

[]NIT DAMAGE HAZARD

Failure to follow this caution may result in equipment
damage or improper operation,

• Use abrazing shield

• Wrap service valves with wet cloth or heat sink material.

Use refrigerant grade tubing. Service valves are closed from factory

and ready for brazing. After wrapping service valve with a wet

cloth, braze sweat connections using industry accepted methods

and materials. Consult local code requirements. Refrigerant tubing
and indoor coil are now ready for leak testing. This check should

include all field and factory joints.
Evacuate Refrigerant Tubing and Indoor Coil

[]NIT DAMAGE HAZARD
Failure to follow this caution may result in equipment

damage or improper operation,
Never use the system compressor as a vacuum pump.

Refrigerant tubes and indoor coil should be evacuated using the
recommended deep vacuum method of 500 microns. The alternate

triple evacuation method may be used. See Service Manual for
triple evacuation method. Always break a vacuum with dry

nitrogen prior to opening the refrigerant system for servicing.

Deep Vacuum Method

The deep vacuum method requires a vacuum pump capable of
pulling a vacuum of 500 microns and a vacuum gauge capable of

accurately measuring this vacuum depth. The deep vacuum method

is the most positive way of assuring a system is free of air and
liquid water. (See Fig. 7)

ffJ
O

II:

o

m

2 3 4 5 6

MINUTES

Fig. 7 - Deep Vacuum Graph

LEAK IN

VACUUM TIGHT
TOO WET

TIGHT

DRY SYSTEM

A95424

Connect Ground and Power Wires
Connect ground wire to ground connection in control box for

safety. Connect power wiring to contactor as shown in Fig. 8,

DISCONNECT
PER N. E. C. AND/OR

LOCAL CODES

CONTACTOR

FIELD POWER ]

WIRING

cc°o

o©

FIELD GROUND

WIRING ]

Fig. 8 - Line Power Connections

-Q

GROUND
LUG

A91056

Final Tubing Check
IMPORTANT: Check to be certain factory tubing on both indoor

and outdoor unit has not shifted during shipment. Ensure tubes are
not rubbing against each other or any sheet metal. Pay close
attention to feeder tubes, making sure wire ties on feeder tubes are
secure and tight.

Step 8 -- Make Electrical Connections

ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal

injury or death.
Do not supply power to unit with compressor ternfinal box

cover removed.

Be sure field wiring complies with local and national fire, safety,
and electrical codes, and voltage to system is within linfits shown

on unit rating plate. Contact local power company for correction of
improper voltage. See unit rating plate for recommended circuit

protection device.
NOTE: Operation of unit on improper line voltage constitutes

abuse and could affect unit reliability. See unit rating plate. Do not
install unit in system where voltage may fluctuate above or below
pernfissible linfits.

NOTE: Use copper wire only between disconnect switch and unit.
NOTE: Install branch circuit disconnect of adequate size per NEC

to handle unit starting current. Locate disconnect within sight from
and readily accessible from unit, per Section 440-14 of NEC.

Route Ground and Power Wires
Remove access panel to gain access to unit wiring. Extend wires

from disconnect through power wiring hole provided and into unit
control box.

ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury

or death.
The unit cabinet must have an uninterrupted or unbroken

ground to nfininfize personal iniury if an electrical fault
should occur. The ground may consist of electrical wire or
metal conduit when installed in accordance with existing

electrical codes.

Connect Control Wiring

Connect to Infinity connections. Only two wires (AB) to Infinity

capable indoor unit (furnace or fan coil) is required. Typical 4 wire
(ABCD) may be connected (see Fig. 18).

IMPORTANT: This system requires the power supply to the
outdoor unit, and the indoor unit, for the UI to communicate with

the outdoor unit.

General Information

Use No. 18 AWG or larger color-coded, insulated (350C
nfininmm) wire for low voltage control wires.

All wiring must be NEC Class 1 and must be separated from
inconfing power leads.

Use furnace transformer, fan coil transformer, or accessory
transformer for control power requirement of system accessories

external to the OD unit. The outdoor unit has its own transformer
power.

Final Wiring Check
IMPORTANT: Check factory wiring and field wire connections to

ensure ternfinations are secured properly. Check wire routing to
ensure wires are not in contact with tubing, sheet metal, etc.

Step 9 -- Compressor Crankcase Heater

This compressor has an internal crankcase heater. Furnish power
to the unit a minimum of 24 hr before starting the unit for the first

time.
To furnish power to heater only, set thermostat to OFF and close

electrical disconnect to outdoor unit.
Power is not required to the indoor unit or User Interface for proper

operation of heater. Crankcase heater will however be intelligently
energized as needed between operations, and otherwise even when

the UI and indoor unit is not installed, as long as there is power to
the outdoor unit even if the indoor unit and UI are not yet installed.

Airflow Setup for Infinity Control Furnace or FE

Fan Coil (communicating)

This system can only be installed with Infinity indoor and user
interface (UI) SYSTXCCUID01-V or SYSTXCCUIZ01-V or

newer. When using an Infinity User Interface, airflow is

automatically selected based on equipment size. The user has the

option of selecting Comfort, Efficiency and Max airflow for
Heating and/or Cooling modes. These should be selected based on

balance between the homeowner's comfort and energy
consumption expectations. See User Interface Installation
Instructions for additional available adjustments.

Due to using a conmmnicating control with the fan coil or the
furnace, dip switch adjustments are not necessary. The outdoor

unit configuration and the indoor airflows are deternfined by
communicating control setup.

Step 10 -- Install Accessories
There are no refrigeration circuit or electrical accessories required

or available for installation within the unit. External to the unit, the
same accessories such as the liquid line solenoid, support feet,
snow rack, wind baffle etc., are available on other Carrier units can

also be used on this line of product. Refer to the individual
Installation Instructions packaged with kits or accessories when

installing.
Step 11 -- Start-Up

[]NIT OPERATION AND SAFETY HAZARD
Failure to follow this caution may result in minor personal

injury, equipment damage or improper operation.
Observe the following:

1. Do not overcharge system with refrigerant.

2. Do not operate unit in a vacuum or at negative pressure.

3. Do not disable low pressure switch

4. Dome temperatures may be hot.

PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal iniury.

Wear safety glasses, protective clothing, and gloves when
handling refrigerant.

HEATPURP,_HE,_K

EHRRSE,_R,_,..u,_R,,u,,

I IIM T I I i-T ,

.... ESE, L_E,lo,H.

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r-TN r* _ •

FRL,uRNL.HARoE.

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__,,ESE, Ruu.

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,u, R,._. IH.HHLB5.

BACK

I- r-

i" I £"1 II TI¢'_N

f i'3

,3._ L85.
U-NLB5.

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Fig. 9 - Required Charge Adjustment Calculated in UI

4. Set User Interface to operate cooling in CHARGING mode.

Charging mode operates system compressor speed and fan
speeds to proper conditions to check the refrigerant charge.

NOTE: Do not check charge in a mode other than CHARGING.

5. Wait for the specified stabilization time, depending on
lineset length. Compare subcooling at liquid line service

valve to Liquid Line Subcooling Target as shown CHAR-

GING screen (LiqLin SC TGT) (see Fig. 10).

,. 7

_HRRu,,,o I18:$9

HEAT PUMP: EOOL-IO0%
_.u,,PRESSuRRPFI: 3255

¢'lt'T n N 3-.

oL,-_EFRu5,. q3 F
5_.,.PRESS: 15qPSIG

If"TInl_

SuL,u,, TEMP: GSF

13 IT i1_

u_, S,uETEFIP: qSF

SUPERHEAT: S.0F

f-i ITI f-IN,

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I_ IIAI T r" •

,_I,Evu,_, RoE. 232U

I I Nil

FhRF.uwEFFI: 8q5

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IL,ILJ/a

ENVIRONMENTAL HAZARD
Failure to follow this caution may result in environmental

damage.
Federal regulations require that you do not vent

refrigerant to the atmosphere. Recover during system
repair or final unit disposal.

Follow these steps to properly start up the system:

1. After system is evacuated, close the disconnects to energize

the ID and OD units to assess the user interface (UI), Keep
system in off mode. Under the Advanced function menu,

assess the REQUIRED CHARGE CALCULATION screen.

Enter the lineset length and vapor tube diameter. The user
interface (UI) will now display the required charge adjust-

ment (see Fig. 9) for the lineset and an adjustment for a
large indoor coil if recognized as such by the UI.

2. Add or remove the required charge adjustment for lineset
length to liquid service valve.

Note: If lineset is less than 15 feet (-9.4°C), charge re-
moval may be necessary.

3. Fully open liquid and vapor service valves.

$ STOP

Al1105

Fig. 10 - Liquid Line Subcooling Target

Step 12 -- System Functions And Sequence Of

Operation

The 25VNA models utilize an Infinity Communicating User
Interface (UI). With a call for cooling, the outdoor fan and

compressor are energized to run at lowest cooling demand. If this
does not satisfy cooling demand, the system will ramp up in stages
until it satisfies the demand. After coping with the higher demand,

the unit returns to lower capacity operation until the demand is
satisfied or until an increase in demand.

When all demand is satisfied, the compressor will shut off. As the
unit operates at lower c@acity, system v@or (suction) pressure will

be higher than it is during a standard single-stage system operation
or during a higher capacity operation.

When the outdoor ambient is more the 100°F (37.8°C), the
outdoor fan will continue to run for one nfinute after compressor
shuts off. This reduces pressure differential for easier starting in

the next cycle.
The conventional thermostat inputs is designed to work for

emergency operation only. Connections are Y, O and C. The
system will only operate at maximum capacity, heating or cooling.

The user interface (UI) displays the operation mode and fault codes

as specified in the troubleshooting section. See Table 5 for codes
and definitions.

NOTE: Only one code will be displayed on the outdoor unit
control board (the most recent, with the highest priority). The

latest codes are stored and can be access via the UI.

Crankcase Heater Operation

This unit has an internal crankcase heater that will be energized
during the off cycle and is intelligently demanded by the system to
prevent the compressor from being the coldest part of the system

thus enhancing the reliability. The crankcase heater will function
as needed any time the outdoor unit is powered. The indoor unit

and UI do not need to be installed for the crankcase heater to
operate properly.

NOTE: Contactor may close intermittently without the unit
starting. This is done to determine whether the control needs to
energize the crankcase heater. Closing the contactor powers the
inverter and allows the system to check compressor temperature.

Outdoor Fan Motor Operation

The outdoor unit control (Fig. 11) energizes outdoor fan anytime
compressor is operating, except for defrost and as needed during

low-ambient cooling operation. The outdoor fan remains
energized if a pressure switch opens or compressor scroll over
temperature should occur. This OD fan is an ECM motor which

operates at varying speeds depending on the ambient and the
demand.

Time Delays

The unit time delays include:

• Five minute time delay to start cooling or heating operation
when there is a call from the user interface. To bypass this

feature, momentarily short and release Forced Defrost pins.

• Five minute compressor re-cycle delay on return from a
brown-out condition.

• See Tab le 7 for other delay information.

General Information

Infinity Controlled low ambient cooling:

This unit is capable of low ambient cooling down to 0°F (-17.8°C)
with Low Ambient enabled on the Infinity Control. A low
ambient kit is not required. The only accessory that may be

required is wind baffles in locations which are likely to experience
cross winds in excess of 5 miles an hour. This generally occurs

only on roof and open area applications. The Infinity Control
provides an automatic evaporator freeze thermostat. Low ambient
cooling nmst be enabled in the User Interface setup. Fan may not

begin to cycle until about 40°F (4.4°C) OAT. Fan will cycle based
on coil and outdoor air temperature.

Infinity controlled low ambient mode operates as follows:

• Fan is OFF when outdoor coil temperature is too low (+
55 ° F/12.7 ° C), the saturated suction pressure indicates a freezing
indoor coil or outdoor fan has been ON for 30 minutes. (Fan is
turned off to allow refrigerant system to stabilize.)

Utility Interface With Infinity Control

The utility curtailment relay should be wired between UTIL and C
connections on the control board for this Infinity Communicating
System (see Fig. 19). This input allows a power utility device to

interrupt compressor operation during peak load periods. When the
utility sends a signal to shut the system down, the User Interface

will display, "Curtailment Active". See UI installation instructions
for setup details.

Communication and Status Function Lights

Infinity Control_ Green Communications (COMM)Light
A green LED (COMM light) on the outdoor board (see Fig. 11)

indicates successful communication with the other system
products. The green LED will remain OFF until conmmnication is

established. Once a valid command is received, the green LED will
turn ON continuously. If no conmmnication is received within 2

minutes, the LED will be turned OFF until the next valid
communication.

Amber Status Light
Amber colored STATUS light indicates operation and error status.

See Table 7 for definitions.

• Two minute time delay to return to standby operation from last

valid communication.

• One minute time delay of outdoor fan at termination of cooling
mode when outdoor ambient is greater than or equal to 100°F
(37.8°C).

• Fifteen second delay at termination of defrost before the
auxiliary heat is de-energized.

Al1139

Fig. 11 - Variable Speed Control Board

• Fan is ON when outdoor coil temperature is too high
(+80°F/26.7°C), the high side pressure is too high or if outdoor

fan has been OFF for 30 minutes. (Fan is turned on to allow
refrigerant system to stabilize)

• Low pressure indication by the suction pressure transducer is
ignored for first 3 minutes during low ambient start up. After 3
minutes, if low pressure trip occurs, then outdoor fan motor is
turned off for 10 minutes, with the compressor running. If
pressure condition is satisfied within 10 minutes then cooling
continues with the outdoor fan cycling per the coil temperature
routine listed above for the remainder of the cooling cycle. If the
suction pressure condition is not satisfied within 10 minutes, then
the normal trip response (shut down cooling operation and
generate LP trip error) will occur.

Defrost

This user interface (UI) offers 5 possible defrost interval times: 30,

60, 90, 120 minutes, or AUTO. The default is AUTO.

Defrost interval times: 30, 60, 90, and 120 minutes or AUTO are
selected by the Infinity Control User Interface (dip switches are not

used.)
AUTO defrost adjusts the defrost interval time based on the last

defrost time as follows:

• When defrost time <3 minutes, the next defrost interval=120
minutes.

• When defrost time 3-5 minutes, the next defrost interval=90
minutes.

• When defrost time 5-7 minutes, the next defrost interval=60
minutes.

• When defrost time >7 minutes, the next defrost interval=30
minutes.

Thecontrolboardaccumulatescompressorruntime. As the

accumulated run time approaches the selected defrost interval time,
the control board monitors the coil temperature sensor for a defrost

demand. If a defrost demand exists, a defrost cycle will be initiated
at the end of the selected time interval. A defrost demand exists

when the coil temperature is at or below 32°F (0°C) for 4 minutes
during the interval. If the coil temperature does not reach 32°F

(0°C) within the interval, the interval timer will be reset and start
over.

• Upon initial power up the first defrost interval is defaulted to 30
minutes. Remaining intervals are at selected times.

• Defrost is only allowed to occur below 50°F (10°C) outdoor
ambient temperature.

The defrost cycle is terminated as described below.

• When OAT is > 35°F (+1.67°C), defrost terminates if outdoor
coil temperature > 50°F (+I0°C).

• When OAT _< 35°F (+1.7°C), defrost will terminate if OCT is
>45°F (+4.4°C).

• Or 10 minutes has passed.

At the defrost termination, the outdoor fan output (ODF) will turn
on 15 seconds before the reversing valve switching.

NOTE: Compressor speed during defrost varies based on outdoor
conditions.

Step 13 -- Check Charge
Charge in CHARGING mode

Factory charge amount and desired subcooling are shown in the
user interface (UI). To properly check or adjust charge, conditions

must be favorable for subcooling charging in cooling mode.
Favorable conditions exist when the outdoor temperature is
between 65°F and 100°F (18°C and 38°C), and the indoor

temperature is between 70°F and 80°F (21°C and 27°C). If the
temperatures are outside of these ranges, weigh-in charge only. If
confirmation is needed return and check subcooling when the

temperatures are within the desired range.
Charging Procedure: Unit is factory charged for 15ft (4.57 m) of

lineset and for smaller rated indoor coil combinations. If any
refrigerant charge adjustment is required based on the indoor coil

combination you select and the line set length you input, the UI
will calculate and display the target subcooling and the amount of
additional charge to be added. Therefore UI is your source of

information for charging the system correctly. Refrigerant charge
adjustment amount for adding or removing 0.6 oz/ft (17.74 g/m) of

3/8 liquid line above or below 15fl (4.57 m) respectively, and an
additional amount of refrigerant charge adjustment (2 lbs) for a
large ID coil if required, is calculated and displayed by the UI.

Perform a final charge check only when in cooling and OD is
between 65°F (18°C) and 100°F (38°C).

NOTE: UI indicates acceptable conditions if outside of this range.
Do not charge if outside 65°F (18°C) and 100°F (38°C) outdoor

temperature.
If the range is acceptable, go the CHARGING screen in the user

interface (UI). At cooling conditions, set the user interface (UI) to
check the charge in cooling mode. Allow system to operate in
cooling mode for the stabilization period as indicated in the user

interface (UI). Once conditions are indicated as favorable and

stable by the user interface (UI), check the system charge by
subcooling method. Compare the subcooling taken at the liquid

service valve to the subcooling target (LiqLin SC TGT) listed on
the charging screen. Add refrigerant if the subcooling is low and
remove charge if subcooling is high. Tolerance should be -2°F.

If any adjustment is necessary, add or remove the charge slowly
(no greater than 0.5 lb per minute) and allow system to operate for

15 minutes to stabilize before declaring a properly charged system.

The use of a commercial charge metering device (restrictor) such as
Imperial liquid low side charger model 535-C or Watsco

ChargeFaster model CH200 is recommended when adding

refrigerant to an operating system. This prevents potential damage
of liquid slugging of the compressor and allows the subcooling to

stabilize quicker.
If the indoor temperature is above 80°F (26.67°C), and the

outdoor temperature is in the favorable range, adjust system charge
by weight based on line length and allow the indoor temperature to

drop to 80°F (26.67°C) before attempting to check system charge
by subcooling method as described above.

If the indoor temperature is below 70°F (21.11°C), or the outdoor
temperature is not in the favorable range, adjust charge for line set
length above or below 15ft (4.57 m) only. Charge level should then
be appropriate for the system to achieve rated capacity. The charge

level could then be checked at another time when the both indoor

and outdoor temperatures are in a more favorable range. This

ensures maximum efficiency and reliability.

Heating Check Chart Procedure

In heating mode, the required charging method is by weigh-in. On
new installation or complete recharge, refer to the REQUIRED

CHARGE CALCULATION screen in the user interface (UI) to
obtain the required charge ac[iustment and/or total charge required.
Use the UI and Heating Check ('harts (Fig. 12 and 13) to check
system operation during heating mode. The indoor conditions

must be between 60°F (15.6°C) and 80°F (26.7°C) to check the
charge. The outdoor coil must be dry and ice/frost free. Do not

check for pressure agreement if the outdoor has rain, mist or snow
present.

Use the Defrost CHECKOUT mode to remove ice or frost from
coil, if present, prior to checking the heating pressures.

To use the Heating Check Chart, the user interface (UI) must be in

CHARGING mode. These charts indicate whether a correct
relationship exists between system operating pressure and air

temperature entering indoor and outdoor units. If pressure and
temperature do not match on chart, system refrigerant charge may

not be correct. DO NOT USE CHART TO ADJUST
REFRIGERANT CHARGE.

NOTE: High pressure is at vapor service valve. Add 12 psig if
high pressure is taken from liquid service valve.

NOTE: When charging is necessary during heating season, charge
must be weighed in accordance with unit rating plate, ---0.6 oz./ft
(---17.74 g/m). of 3/8-in. liquid-line above or below 15 ft (4.57
m)., respectively.

NOTE: In heating mode, check refrigerant pressures only when
user interface is in CHARGING mode and indicates stable. If

charge is in doubt, remove charge and weigh-in correct calculated
refrigerant charge.

10

ChargingIn Cooling M0de- 25VNA048/060

See user interface set #1Charging Mode

Heating Check Chart - 25VNA048/060

For use in Heating Charging Modeorgy

Al1140

25VNA024/036 Heating Pressure check Cha_ (Psig)

OD DB

(°F)

60 324 121 360 120 407 121
50 293 99 333 100 300 102

40 277 87 307 80 360 88
30 257 69 288 65 333 69
20 242 57 281 60 320 60
10 232 50 263 47 306 50

0 218 42 253 43 288 42

Fig. 12 - Heating Pressure Check Chart 25VNA024/036

60 70 80

High Low High Low High Low

Indoor Temperature (°F)

Step 14 -- Pumpdown & Evacuation

If this system requires either a Pump Down or Evacuation for any
reason, the procedures below must be followed:

Pump Down
Because this system has an inverter controlled, compressor, suction

pressure transducer and EXV, conventional procedure cannot be
used to "pump down" and isolate the refrigerant into the outdoor
unit. The UI (User Interface) has provisions to assist in performing

this function.

1. Connect gages to 25VNA liquid and vapor or suction capil-
lary service ports to monitor operating pressures during and

at completion of the procedure.

2. In the advanced menu of the UI, go to Checkout > Heat
Pump> Pumpdown

3. Select mode to pump down in (COOL or HEAT), COOL
mode allows refrigerant to be isolated in outdoor unit.

HEAT mode allows the refrigerant to be isolated in indoor
coil and lineset. Set desired time period. Default time peri-

od for the procedure is 120 minutes.

4. Select Start on UI to begin the pumpdown process. Unit
will begin running in selected mode after a brief delay.

5. Close the liquid service valve.

6. The unit will run in selected mode with the low pressure
protection set to indicate pumpdown is complete when the

suction pressure drops below 0 psig. Compressor protec-
tions are still active to prevent damage to the compressor or

inverter (high pressure, high current, high torque, scroll
temperature, etc.).

7. Once system indicates pumpdown complete or failure to
complete shutdown, close vapor service valve.

8. If pumpdown does not complete due to compressor safety
shutdown, a recovery system will be required to remove fi-

nal quantity of refrigerant from indoor coil and line set.

9. Remove power from indoor and heat pump unit prior to ser-
vicing unit.

Al1141

25VNA048/060 Heating Pressure check Chaff (Psig)

OD DB

(°F)

60 324 121 360 120 407 121
50 293 99 333 100 380 102

40 277 87 307 80 360 88
30 257 69 288 65 333 69
20 242 57 281 60 320 60
10 232 50 263 47 306 50

0 218 42 253 43 288 42

Fig. 13 - Heating Pressure Check Chart 25VNA048/060

60 70 80

High Low High Low High Low

Indoor Temperature (°F)

NOTE: A small quantity of charge remains in the OD unit that
must be manually recovered if isolating refrigerant to indoor coil

and lineset via HEAT mode PUMP DOWN.

Evacuation and Recovery of Refrigerant from within

25VNA

Because this system has an EXV for the heating expansion device,

additional steps must be taken to open the EXV if the heat pump

unit must be evacuated for service reasons. If the EXV is not open
when pulling a vacuum or recovering refrigerant from the heat

pump unit, extended evacuation time may be required and/or
inadequate vacuum obtained. The UI (User Interface) has

provisions to open the EXV for refrigerant recovery and/or
evacuation.

1. Connect gages to 25VNA liquid and vapor or suction capil-
lary service ports to monitor operating pressures during and

at completion of the procedure. Attach recovery system or

vacuum pump to gage set as needed for the service proced-

ure. The service valves must be open to evacuate the unit
through the line set service ports. The suction capillary ser-

vice port is a direct connection to the suction port of the

compressor.

2. In the advanced menu of the UI, go to Checkout > Heat
Pump> > Evacuation.

3. Set desired time period. Default time period for the proced-
ure is 120 minutes.

4. Select START on UI to open the valve.

5. Begin evacuation or refrigerant recovery as required for the
procedure after UI indicates the EXV is open. Power may

be removed from heat pump after the UI indicates "READY

TO EVACUATE."

6. Remove power from indoor and heat pump unit prior to ser-
vicing unit. The EXV will retain the open position.

NOTE: See service training materials for troubleshooting the
EXV using EXV CHECK mode.

11

MAJOR COMPONENTS

Variable speed Control Board

The HP control board controls the following functions:

• Compressor speed

• Contactor operation

• Outdoor fan motor operation

• Reversing valve operation

• Defrost operation

• Low ambient cooling

• Crankcase heater operation

• Pressure switch monitoring

• Time Delays

• .Pressure Transducer

• .EXV operation control

• .Inverter communication and control

Inverter

The inverter is located inside the control box. This is an air-cooled
device that communicates with the control board and drives the

compressor to the demanded RPM. When the contactor closes, it
powers the inverter with line voltage. The inverter changes the line

voltage to 410 volts DC 3-phase, and varies the frequency to drive
the compressor at the desired RPM.

NOTE: Manually closing the contactor will not cause the unit to

operate. The unit must be operated with an Infinity Control. A
standard thermostat will allow operation only in the emergency

mode (high speed heating or cooling).
Variable Speed Compressor

This unit contains a variable speed compressor that has a wide
operating range. It operates on 410vdc provided by the inverter.
This compressor can only be operated by the specific inverter

supplied with the unit.

EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage

and/or improper operation.
Do not attempt to apply line voltage directly to the

compressor. This will destroy the compressor.

Electronic Expansion Valve (EXV)
This unit uses an electronic expansion valve for refrigerant

metering in the heating mode. The control board drives the EXV to
its proper position based on the operating mode and conditions.

The Infinity Control Service mode allows for manual opening and
closing of the EXV for troubleshooting and pump down.
Field control Connections

For normal operation use the ABCD Infinity connections only.
Only two wires, AB are required. See Fig. 18. Discrete inputs (Y,C,
O) are available for emergency operation if the Infinity Bus is not

in operation.
Pressure Transducer (SPT)
A 5 VDC output low pressure transducerthat provides a 0-5 VDC

data for interpretation by the control board for a 0 to 200 psig
range of pressure at the suction tube. This interpreted pressure data

is then intelligently used by the control board for low pressure
cut-out, loss of charge management, compressor overall envelope
management, oil circulation management, lubrication management

and EXV control. (See Fig. 17.)

Compressor Control Contactor

The contactor has a 24 volt coil. The electronic control board
controls the operation of the contactor.

TROUBLESHOOTING

Systems Communication Failure

If conmmnication with the Infinity control is lost with the User
Interface (UI), the control will flash the appropriate fault code (see

Table 7). Check the wiring to the User Interface and the indoor and
outdoor units and power.

Model Plu_
Each control board contains a model plug. The correct model plug

must be installed for the system to operate properly (see Table 3).

Table 3 - Model Plug Information

MODEL

NUMBER

25VNA024 HK7OEZO01
25VNA036 HK7OEZO02

25VNA048 HK7OEZO03
25VNA060 HK7OEZO04

MODEL PLUG

NUMBER

The model plug is used to identify the type and size of unit to the
control.

On new units, the model and serial numbers are input into the

board's memory at the factory. If a model plug is lost or nfissing at
initial installation, the unit will operate according to the

information input at the factory and the appropriate error code will
flash temporarily. An RCD replacement board contains no model

and serial information. If the factory control board fails, the model

plug must be transferred from the original board to the replacement
board for the unit to operate.

NOTE: The model plug takes priority over factory model
information input at the factory. If the model plug is removed after

initial power up, the unit will operate according to the last valid
model plug installed, and flash the appropriate fault code
temporarily.

Pressure Switch Protection
The outdoor unit is equipped with high pressure switch. If the

control senses the opening of a high pressure switch, it will
respond as follows:

1. De-energize the contactor.

2. Keep the outdoor fan operating for 15 nfinutes.

3. Display the appropriate fault code (see Table 7).

4. After a 15 nfinute delay, if there is a call for cooling or heat-
ing and HPS is reset, the contactor is energized.

5. If HPS has not closed after a 15 nfinute delay, the outdoor
fan is turned off. If the open switch closes anytime after the

15 nfinute delay, then resume operation with a call for cool-
ing or heating at a temporary reduced capacity.

6. If HPS trips 3 consecutive cycles, the unit operation is
locked out for 4 hours.

7. In the event of a high-pressure switch trip or high-pressure
lockout, check the refrigerant charge, outdoor fan operation,

and outdoor coil (in cooling) for airflow restrictions, or in-
door airflow in heating.

8. In the event of a low-pressure trip or low-pressure lockout,
check the refrigerant charge and indoor airflow (cooling)

and outdoor fan operation and outdoor coil in heating.

Control Fault

If the outdoor unit control board has failed, the control will flash
the appropriate fault code (see Table 7). The control board should

be replaced.

PIN RESISTANCE

(K-ohms)

Pins 1-4 Pins 2-3

5.1K 11K

5.1K 18K

5.1K 24K

5.1K 33K

12

Brown- Out Protection

If the line voltage is less than 187v for at least 4 seconds, the

contactor and fan relay are de-energized. Compressor and fan
operation are not allowed until voltage is a nfininmm of 190v. The

control will flash the appropriate fault code (see Table 7).

230V Line (Power Disconnect) Detection

If there is no 230v at the contactor when the indoor unit is powered

with a cooling or heating demand, the appropriate fault code is
displayed. Verify the disconnect is closed and 230v wiring is

connected to the unit.

Inverter Voltage Sensin_

The control board senses the presence or absence of 230 V through

the feedback from inverter. The control monitors the high voltage
to the inverter. Voltage should be present anytime the contactor is

energized and voltage should not be present when the contactor is
de-energized.

Temperature Thermistors

Thermistors are electronic devices which sense temperature. As the
temperature increases, the resistance decreases. Thermistors are

used to sense outdoor air (OAT), coil temperature (OCT) and the
suction line thermistor (OST) located between the reversing valve

and the accumulator.
Refer to Table 4 and Fig. 14 for resistance values versus

temperature.

Table 4 - Resistance Values versus Temperature

TEMPERATURE RESISTANCE(ohms)

25.0°C (77.0°F) 10.0+/- 2.3%

0.0°C (32.0 ° F) 32.6 + / - 3.2%

-28.0°C (-18.4 ° F) 85.5 +/- 3.4%

THERMISTOR CURVE

90,

->10°F (->5.6°C) cooler than the coil sensor, the sensors are out
of range.

If the sensors are out of range, the control will flash the appropriate
fault code as shown in Table 7.

The thermistor comparisons are not performed during low ambient
cooling or defrost operation.

Failed Thermistor Default Operation
Factory defaults have been provided in the event of failure of

outdoor air thermistor (OAT) and/or outdoor coil thermistor
(OCT).

If the OAT sensor should fail, low ambient cooling will not be

allowed and the one-minute outdoor fan off delay will not occur.

Defrost will be initiated based on coil temperature and time.
If the OCT sensor should fail, low ambient cooling will not be

allowed. Defrost will occur at each time interval during heating

operation, but will terminate after 5 minutes.
If there is a thermistor out-of-range error, defrost will occur at

each time interval during heating operation, but will terminate after
5 minutes.

Count the number of short and long flashes to determine the
appropriate flash code. Table 7 gives possible causes and actions

related to each error.

Outdoor Coil Thermistor

The outdoor coil thermistor is a 10Kohm resistor used for nmltiple
system operations. It provides the coil/liquid line temperature to

the heat pump board and user interface. Low ambient operation,
defrost initiation, defrost termination and assistance with OAT

temperature measurement of some of the functions. The sensor
must be securely mounted to the tube connecting the EXV and
distributor. See Fig. 15 for proper placement. See Table 4 for

proper resistances.

OATThermistor must be
locked in place with

spherical nib end facing
towards the front of the

20 40 80 80 100 120

TEMPERATURE(DEG._

A91431

Fig. 14 - Thermistor Resistance Versus Temperature

If the outdoor air or coil thermistor should fail, the control will

flash the appropriate fault code (see Table 7.)
IMPORTANT: The outdoor air thermistor, coil thermistor and

suction thermistor should be factory mounted in the final
locations. Check to ensure thermistors are mounted properly
(See Fig. 15, 16 and 17).

Thermistor Sensor Comparison
The control continuously monitors and compares the outdoor air

temperature sensor and outdoor coil temperature sensor to ensure
proper operating conditions. The comparison is:

• In cooling if the outdoor air sensor indicates ->10 °F (->5.6 ° C)
warmer than the coil sensor (or) the outdoor air sensor indicates

->20 °F (-> 11 ° C) cooler than the coil sensor, the sensors are out
of range.

• In heating if the outdoor air sensor indicates ->35 °F (-> 19.4 ° C)
warmer than the coil sensor (or) the outdoor air sensor indicates

f ---

_ ..... /1

Al1142

Fig. 15 - OAT Thermistor Location (Bottom of Control Box)

Al1143

Fig. 16 - Outdoor Coil Thermistor (OCT) Attachment

(On Distributor Tube)

13

PRESSURETRANSDUCER(SPT)

SUCTION THERMISTOR

REVERSING VALVE

SUCTION SERVICE VALVE

ACCUMULATOR TUBE

ECM Fan Motor

If verification of proper operation is required for the ECM motor
used in this unit, follow these steps:

1. Verify that the 230v input to the transformer is present.

2. Verify that the control board is powered 18 volts to 30 volts
from the transformer.

3. With the UI in charging mode in cooling, measure the DC

voltage between the PWM 1 and PWM 2 terminals on the

outdoor control board. The DC voltage and PWM (option-
al) measured nmst be as shown in Table 6.

Table 6 - DC Voltage and PWM Measurement

Terminals Voltage PWM

2T and 3T 8.9VDC 52
4T and 5T 11.1VDC 84

Al1103

Fig. 17 - Suction Thermistor (OST) Attachment

(On Suction Tube)

Suction Thermistor (OST)
Suction Thernfistor is used for assisting in EXV control and must

be secured on the suction tube and aligned longitudinally to the
vertical surface of the tube axis (see Fig. 17).

UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment

damage or improper operation.
In order to nfininfize the ambient influence, make sure the

thernfistor curved surface hugs the pipe surface and is
secured tight using the wire tie fished through the original

slot insulating polymer body.

Variable Speed Compressor Sensor Output Terminals
This compressor has a motor thermistor and a scroll thermistor.

Correct resistance between scroll thermistor terminal and common
is 10k at 77°F (25°C). Correct resistance between motor

thermistor terminal and common is 5k at 77 °F (25 o C).

Variable Speed Compressor Power Input Terminals

This compressor operates with a 3-phase variable frequency PWM
variable voltage to the three fusite terminals.

Table 5 - Variable Speed Compressor Resistances

(winding resistance at 70°F 4- 20°F)

WINDING 25VNA036 25VNA060

Betweenterminals

T1, T2, and T3 .681 .203

Between terminal &

ground >1 mega OHM >1 mega OHM

25VNA024 25VNA048

Status Codes

Table 7 shows the status codes flashed by the amber status light.
Most system problems can be diagnosed by reading the status code

as flashed by the amber status light on the control board.

The codes are flashed by a series of short and long flashes of the
status light. The short flashes indicate the first digit in the status

code, followed by long flashes indicating the second digit of the
error code.

The short flash is 0.25 seconds ON and the long flash is 1.0 second

ON. Time between flashes is 0.25 seconds. Time between short

flash and first long flash is 1.0 second. Time between code
repeating is 2.5 seconds with LED OFF.

Codes are easily read from user interface (UI)

EXAMPLE:
3 short flashes followed by 2 long flashes indicates a 32 code.

Table 7 shows this to be low pressure switch open.

User Interface (U[) Furnace or Fan Coil

,m_Hm

....... i A _='=

Humidifier

,m I t_ I,,= =

t,===,l

,_11© i

CandD

25VNA HP

Al1144

Fig. 18 - Infinity Furnace or Fan Coil Wiring with

Communicating Variable Speed HP

[]NIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage

and/or improper operation.
Do not use Meggar for measuring the winding resistance.

Emergency Mode Connections with a Conventional
Dual Fuel Thermostat

In an emergency, it is possible to replace the UI with a
conventional heat pump thermostat (nmst be dual fuel capable if
using a furnace), see Fig. 21 for wiring. However, this emergency

mode operation is linfited to a single, maximum compressor speed
in heating and a single maximum cooling speed.

14

t i

i
i

....... ; ._1..... ,,

i

Utili:cy Interface*

* FROM UTILITY PROVIDER

Fig. 19 - Variable Speed Control Board

with optional Utility Relay

Al1381

t _

....., LLS r ....

i .i

Fig. 20 - Variable Speed Control Board connected to optional Liquid Line Solenoid.

15

Al1379

Fan Coi:I

OF

25VHA

Thenl_ostat

m

UT

m

mE

mM

C "-

LS

O

Fig. 21 - Variable Speed Unit Connected to a Conventional Dual Fuel Thermostat in an Emergency Mode

O

Al1382

16

Table 7 - Troubleshooting

FAULT DESCRIPTION SENT TO Ul RESET TIME

-- ON, no flash

- - 1, pause

Communications Loss NA
Invalid Model NA

High Pressure Switch Open 15
Low Pressure Trip 15

Control Fault NA
Brownout Revert to 5 min cycle delay

Lost Inverter Communications Revert to 5 min cycle delay

230VAC Dropout-Reset Event Revert to 5 min cycle delay

Outdoor Air Temp Sensor Fault NA
Suction Temp Sensor Fault 15

Coil Temp Sensor Fault NA
OAT-OCT Thermistor Out of range NA

Suction Pressure Sensor Fault 15
OAT-OST Thermistor Out of range 5

Compressor Scroll Temp Out of Range 15
Compressor Sump Heating Active 2 HOURS

Inverter / Compressor Internal Fault 15
Compressor Motor Temp Out of Range 15
Suction Over Temperature 15

Inverter Temp Out of Range Event 15
Inverter Over Current 15

Compressor No-Pump Event 15
Suction Over Temp Lockout 4 Hours

Low Pressure Lockout for 4 hours 4 HOURS
High Pressure Lockout for 4 hours 4 HOURS

Compressor Temp Lockout 4 HOURS
Compressor Temp Sensor Fault 15

Inverter Temp Lockout 4 HOURS
Inverter VDC-Out Over Voltage 15

Inverter VDC- Out Under Voltage 15
230VAC Under Voltage 15
230VAC Over Voltage 15

High Current Lockout 2 HOURS
VDC Under Voltage Lockout 2 HOURS
VDC Over Voltage Lockout 2 HOURS

High Torque Event 10

High Torque Lockout 2 HOURS

-- NA

Variable Capacity or Emergency

Variable Speed Range Cutback

FLASH CODE

(AMBER LED)

Standby

Mode

16
25
31

32
45
46

48
49
53

54
55
56
57

58
59
68

69
71
72

75
77
79

82
83
84

85
86
88

91
92
93

94
95
96

97
98
99

OFF

(minutes)

1 (2 sec ON), longer pause (1

second OFF)

17

FINAL CHECKS

IMPORTANT: IMPORTANT: Before leaving job, be
sure to do the following:

1. Ensure that all wiring is routed away from tubing
and sheet metal edges to prevent rub-through or

wire pinching.

2. Ensure that all wiring and tubing is secure in unit
before adding panels and covers. Securely fasten

all panels and covers.

3. Tighten service valve stem caps to 1/12-turn past
finger tight.

4. Leave Users Manual with owner. Explain system
operation and periodic maintenance requirements

outlined in manual.

5. Fill out Dealer Installation Checklist and place in
customer file.

For continuing high performance and to minimize
possible equipment failure, periodic maintenance must be

performed on this equipment.
Frequency of maintenance may vary depending upon

geographic areas, such as coastal applications. See

Owner's Manual for information.

CARE AND MAINTENANCE

PURON® (R-410A) REFRIGERANT QUICK REFERENCE GUIDE

• Puron refrigerant operates at 50-70 percent higher pressures than R-22. Be sure that servicing equipment and replacement
components are designed to operate with Puron refrigerant.

• Puron refrigerant cylinders are rose colored.

• Recovery cylinder service pressure rating must be 400 psig, DOT 4BA400 or DOT BW400.

• Puron refrigerant systems should be charged with liquid refrigerant. Use a commercial type metering device in the manifold hose
when charging into suction line with compressor operating.

• Manifold sets should be 700 psig high side and 180 psig low side with 550 psig low-side retard.

• Use hoses with 700 psig service pressure rating.

• Leak detectors should be designed to detect HFC refrigerant.

• Puron refrigerant, as with other HFCs, is only compatible with POE oils.

• Vacuum pumps will not remove moisture from oil.

• Do not use liquid-line filter driers with rated working pressures less than 600 psig.

• Do not leave Puron refrigerant suction line filter driers in line longer than 72 hours.

• Do not install a suction-line filter drier in liquid-line.

• POE oils absorb moisture rapidly. Do not expose oil to atmosphere.

• POE oils may cause damage to certain plastics and roofing materials.

• Wrap all filter driers and service valves with wet cloth when brazing.

• A factory-approved liquid-line filter drier is required on every unit.

• Do NOT use an R-22 TXV.

• If indoor unit is equipped with an R-22 TXV or piston metering device, it must be changed to a hard-shutoff Puron refrigerant
TXV.

• Never open system to atmosphere while it is under a vacuum.

• When system must be opened for service, recover refrigerant, evacuate then break vacuum with dry nitrogen and replace filter
driers. Evacuate to 500 microns prior to recharging.

• Do not vent Puron refrigerant into the atmosphere.

• Do not use capillary tube coils.

• Observe all warnings, cautions, and bold text.

• All indoor coils must be installed with a hard-shutoff Puron refrigerant TXV metering device.

Copyright 2011 Carrier Corp. * 7310 W. Morris St. * Indianapolis, IN 46231 Printed in U.S.A. Edition Date: 07/11

Manufacturer reserves the right to change, at any time, specification8 and design8 without notice and without obligations,

18

Catalog No: 25VNA-3SI

Replaces: 25VNA- 2Sl