Carrier 38AUQ User Manual

38AUQ

Heat Pump Condensing Units 60 Hz

with Puron® (R-410A) Refrigerant Sizes 07, 08, and 12

Installation, Start-Up and

Service Instructions

CONTENTS

SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . 1 INSTALLATION GUIDELINES. . . . . . . . . . . . . . . . . . . . . . . 2 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14 Step 1 – Plan for Unit Location . . . . . . . . . . . . . . . . . . . 7 Step 2 – Complete Pre-Installation Checks. . . . . . . . . . 7 Step 3 – Prepare Unit Mounting Support . . . . . . . . . . 7 Step 4 – Rig and Mount the Unit . . . . . . . . . . . . . . . . . . 7 Step 5 – Complete Refrigerant Piping Connections . . . 7 Step 6 – Install Accessories. . . . . . . . . . . . . . . . . . . . . . 10 Step 7 – Complete Electrical Connections . . . . . . . . . 10 PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Turn On Crankcase Heater . . . . . . . . . . . . . . . . . . . . . . 15 Preliminary Charge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 START-UP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 -18 38AUQ Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 OPERATING SEQUENCE. . . . . . . . . . . . . . . . . . . . . . . . . . 19 Indoor (Supply) Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Cooling Unit Without Economizer. . . . . . . . . . . . . . . . . 19 Cooling, Unit With Economizer . . . . . . . . . . . . . . . . . . . 19 Heating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Supplemental Heating/Emergency Heating . . . . . . . . 19 Defrost Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Cooling and Heating Shutdown. . . . . . . . . . . . . . . . . 19 ROUTINE SYSTEM MAINTENANCE. . . . . . . . . . . . . . . 20 Quarterly Inspection (and 30 days after initial start). . 20 SERVICE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 - 31 Refrigeration System . . . . . . . . . . . . . . . . . . . . . . . . . 20 Compressor Oil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Servicing Systems on Roofs with

Synthetic Materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Liquid Line Filter Drier . . . . . . . . . . . . . . . . . . . . . . . . . 21 Filed Refrigerant Access Ports . . . . . . . . . . . . . . . . . 21 Outdoor Coil Metering Devices. . . . . . . . . . . . . . . . . 21 Refrigerant System Pressure Access Ports . . . . . . . . 21 Heat Pump Controls. . . . . . . . . . . . . . . . . . . . . . . . . . 22 Commercial Defrost Board . . . . . . . . . . . . . . . . . . . . . . 22 Crankcase Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Compressor Protection. . . . . . . . . . . . . . . . . . . . . . . . . . 22 Low-Pressure Switches . . . . . . . . . . . . . . . . . . . . . . . . . 33

Comfort Alert Diagnostic Module . . . . . . . . . . . . . . 28 Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Outdoor Coil Maintenance and Cleaning Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Service Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Fastener Torque Values . . . . . . . . . . . . . . . . . . . . . . . 31 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

APPENDIX A

Air Conditioner and Heat Pump with Puron® –

Quick Reference Guide . . . . . . . . . . . . . . . . . . . . . . . 33 APPENDIX B

Wiring Diagram List. . . . . . . . . . . . . . . . . . . . . . . . . 33 APPENDIX C

Motormaster Sensor Locations. . . . . . . . . . . . . . . . . 34 START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . .CL-1, CL-2

SAFETY CONSIDERATIONS

Improper installation, adjustment, alteration, service, maintenance, or use can cause explosion, fire, electrical shock or other conditions which may cause 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 must use factory-authorized kits or accessories when modifying this product. Refer to the individual instructions package

Follow all safety codes. Wear safety glasses and work gloves. Use quenching cloths for brazing operations and have a fire extinguisher available. Read these instructions thoroughly and follow all warnings or cautions attached to the unit. Consult local building codes and appropriate national electrical codes (in USA, ANSI/NFPA70, National Electrical Code (NEC); in Canada, CSA C22.1) for special requirements.

It is important to recognize safety information. This is the safety-alert symbol . When you see this symbol on the unit and in instructions or manuals, be alert to the potential for personal injury.

Understand the signal words DANGER, WARNING, CAUTION, and NOTE. These words are used with the safetyalert 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 may result in minor personal injury or product and property damage. NOTE is used to highlight suggestions which will result in enhanced installation, reliability, or operation.

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could cause personal injury or death.

Before performing service or maintenance operations on unit, always turn off main power switch to unit and install lockout tag. Unit may have more than one power switch.

UNIT OPERATION AND SAFETY HAZARD

Failure to follow this warning could cause personal injury, death and/or equipment damage.

Puron® (R-410A) refrigerant systems operate at higher pressures than standard R-22 systems. Do not use R-22 service equipment or components on Puron refrigerant equipment.

PERSONAL INJURY AND ENVIRONMENTAL HAZARD

Failure to follow this warning could cause personal injury or death.

Relieve pressure and recover all refrigerant before system repair or final unit disposal.

Wear safety glasses and gloves when handling refrigerants. Keep torches and other ignition sources away from refrigerants and oils.

CUT HAZARD

Failure to follow this caution may result in personal injury.

Sheet metal parts may have sharp edges or burrs. Use care and wear appropriate protective clothing, safety glasses and gloves when handling parts and servicing 38AUQ units.

INSTALLATION GUIDELINE

Replacement /Retrofit – R22 to Puron®

Split system heat pumps are intended to be installed with matching indoor sections only. The 38AUQ heat pump outdoor units are matched only with same-size 40RUQ indoor sections. Existing R-22 indoor coils cannot be converted to R-410A heat pump duty. Only the existing refrigerant piping is a candidate for retrofit use.

Acid test – If the existing system is being replaced because of a compressor electrical failure, assume acid is in system. If system is being replaced for any other reason, use an approved acid test kit to determine acid level. If even low levels of acid are detected, install a 100 percent activated alumina suction line filter drier in addition to the replacement liquid-line filter drier. Operate this system in COOLING ONLY. Remove the suction line filter drier as soon as possible, with a maximum of 72 hr of operation.

Recommendation: Install a ball valve in the liquid line at the filter drier location when installing a suction filter in the suction line.

Installation –

1.Remove the existing evaporator coil or fan coil and install the replacement coil.

2.Drain oil from low points and traps in suction line tubing if they were not replaced.

3.Remove the existing outdoor unit. Install the new outdoor unit according to these installation instructions.

4.Install the factory-supplied liquid-line filter drier at the indoor coil just upstream of the TXV.

UNIT DAMAGE HAZARD

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

Never install suction-line filter drier in the liquid-line of a Puron® system.

5.If required, install a 100% activated alumina suction line filter drier at the outdoor unit.

6.Evacuate and charge the system according to the instructions in this installation manual.

7.Operate the system for 10 hr. Monitor the pressure drop across the suction line filter drier. If pressure drop exceeds 3 psig (21kPa), replace suction-line and liquid-line filter driers. Be sure to purge system with dry nitrogen and evacuate when replacing filter driers. Continue to monitor the pressure drop across suction-line filter drier. Repeat filter changes is necessary. Never leave suctionline filter drier in system longer than 72 hr (actual time).

2

	Standard		Corner			Corner			Corner			Corner				Center of Gravity				Unit Height
UNIT	Weight			A			B			C			D
	lbs.	kg.	lbs.		kg.	lbs.		kg.	lbs.		kg.	lbs.		kg.	X		Y		Z	H
38AUQ*07	444	201	134		61	97		44	90		41	123		56	23		26		13	42-3/8
															[584]		[660]		[330]	[1076]
38AUQ*08	483	219	162		74	110		50	85		39	125		57	20		24		13	42-3/8
															[508]		[610]		[330]	[1076]
38AUQ*12	575	261	186		84	126		57	106		48	157		71	21		24		23	50-3/8
															[533]		[610]		[584]	[1280]

Fig. 1 — 38AUQ*07-12 Unit Dimensions

3

Table 1A — Physical Data — 38AUQ*07-12 Units — 60 Hz English

UNIT SIZE 38AUQ		*07		*08		*12
NOMINAL CAPACITY (tons)		6		7.5		10
OPERATING WEIGHTS (lb)
	Aluminum-Fin Coils	444		483		575
REFRIGERANT TYPE‡				R-410A
	Operating Charge, Typical (lb)†	18.0		21.0		27.0
	Shipping Charge (lb)	10.0		12.0		15.0
COMPRESSOR
	Qty...Type	1...Scroll		1...Scroll		1...Scroll
OUTDOOR FANS
	Qty...Rpm	2...1100		2...1100		2...1100
	Motor Hp	1/4		1/4		1/4
	Diameter (in)	22		22		22
	Nominal Airflow (Cfm Total)	6,000		6,000		6,000
	Watts (Total)	610		610		610
OUTDOOR COIL (Qty)		1...Round		Tube/Plate Fin (RTPF)
	Face Area (sq ft total)	17.5		23.0		28.1
	Rows/Fins per inch (FPI)	2/17		2/17		2/17
CONTROLS
	Pressurestat Settings (psig)
	High Cutout	630 ±10		630 ±10		630 ±10
	Cut-in	505 ±20		505 ±20		505 ±20
	Low Cutout	27 ±3		27 ±3		27 ±3
	Cut-in	44 ±5		44 ±5		44 ±5
PIPING CONNECTIONS (in. ODS)		1...11/8		1...11/8		1...13/8
	Qty...Vapor
	Qty...Liquid	1...3/8		1...1/2		1...1/2
LEGEND
ODS — Outside Diameter Sweat (socket)
‡	Unit is factory-supplied with partial charge only.
†	Typical operating charge with 25 ft of interconnecting piping.

4

Table 1B — Physical Data — 38AUQ*07-12 Units — 60 Hz SI

UNIT SIZE 38AUQ	*07		*08		*12
NOMINAL CAPACITY (kW)	21.1		26.4		35.1
OPERATING WEIGHT (kg)
Aluminum-Fin Coils	201		219		261
REFRIGERANT TYPE‡			R-410A
Operating Charge, Typical (kg)†	8.2		9.5		12.2
Shipping Charge (kg)	4.5		5.9		6.8
COMPRESSOR
Qty...Type	1...Scroll		1...Scroll		1...Scroll
CONDENSER FANS
Qty...r/s	2...18		2...18		2...18
Motor Hp NEMA	1/4		1/4		1/4
Diameter (mm)	560		560		560
Nominal Airflow (L/s)	2832		2832		2832
Watts (Total)	610		610		610
CONDENSER COIL (Qty)	1...Round		Tube/Plate Fin (RTPF)
Face Area (sq m total)	1.6		2.1		2.6
Rows/Fins per Meter (Fins/m)	2/670		2/670		2/670
CONTROLS
Pressurestat Settings (kPa)
High Cutout	4344 ±70		4344 ±70		4344 ±70
Cut-in	3482 ±138		3482 ±138		3482 ±138
Low Cutout	186 ±21		186 ±21		186 ±21
Cut-in	303 ±35		303 ±35		303 ±35
PIPING CONNECTIONS (in. ODS)	1...11/8		1...11/8		1...13/8
Qty...Vapor
Qty...Liquid	1...3/8		1...1/2		1...1/2

LEGEND

NEMA — National Electrical Manufacturers Association

ODS — Outside Diameter Sweat (socket)

‡ Unit is factory-supplied with partial charge only.

† Typical operating charge with 7.62 m of interconnecting piping.

5

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

3 8 A U Q A 1 2 A 0 C 6 – 0 A 0 A 0

_____________ ____

Model Type

38AU= Carrier Condensing Unit Puronr R---410A Refrigerant

Type of Coil

Q = Heat Pump Scroll Compressor

Refrigerant Options

A = None

B = Low Ambient

Nominal Tonnage

07 = 6 Tons

08 = 7.5 Tons

12 = 10 Tons

Not Used

A = Not Used

Not Used

0 = Not Used

Coil Options

A= Al/Cu

B = Precoat Al/Cu

C = E-Coat Al/Cu

E= Cu/Cu

M= Al/Cu with Hail Guard

N = Precoat Al/Cu with Hail Guard

P = E-Coat Al/Cu with Hail Guard

R = Cu/Cu with Hail Guard

Packaging

0 = Standard

1 = LTL

Electrical Options

A = None

C = Non-Fused Disconnect

Service Options

0 = None

1 = Un-powered Convenience Outlet

2 = Powered Convenience Outlet

Not Used

A = Place Holder

Base Unit Controls

0 = Electro-Mechanical Controls

Design Revision

A= Initial Rev (Discrete Model Number)

Voltage

1 = 575/3/60

5 = 208/230/3/60

6 = 460/3/60

Fig. 2 — Model Number Nomenclature

POSITION NUMBER		1		2	3	4		5		6		7		8	9	10
TYPICAL		4		8	0	9		G		1		2		3	4	5
	POSITION								DESIGNATES
		1−2					Week of manufacture (fiscal calendar)
		3−4					Year of manufacture (Ó09Ó = 2009)
	5					Manufacturing location (G = ETP, Texas, USA)
		6−10						Sequential number

Fig. 3 — Serial Number Nomenclature

6

.INSTALLATION

Jobsite Survey

Complete the following checks before installation.

1.Consult local building codes and the NEC (National Electrical Code) ANSI/NFPA 70 for special installation requirements.

2.Determine unit location (from project plans) or select unit location.

3.Check for possible overhead obstructions which may interfere with unit lifting or rigging.

Step 1 — Plan for Unit Location

Select a location for the unit and its support system (pad, rails or other) that provides for the minimum clearances required for safety. This includes the clearance to combustible surfaces, unit performance and service access below, around and above unit as specified in unit drawings. See Fig. 4.

Select a unit mounting system that provides adequate height to allow for removal and disposal of frost and ice that will form during the heating-defrost mode.

NOTE: Consider also the effect of adjacent units on airflow performance and control box safety clearance.

Do not install the outdoor unit in an area where fresh air supply to the outdoor coil may be restricted or when recirculation from the condenser fan discharge is possible. Do not locate the unit in a well or next to high walls.

Evaluate the path and required line length for interconnecting refrigeration piping, including suction riser requirements (outdoor unit above indoor unit), liquid line lift (outdoor unit below indoor unit) and hot gas bypass line. Relocate sections to minimize the length of interconnecting tubing.

DO NOT BURY REFRIGERATION LINES.

Although unit is weatherproof, avoid locations that permit water from higher level runoff and overhangs to fall onto the unit.

		RIGHT:
	REAR:	Min 18” (457 mm)
		requried for service
	Min 18” (457 mm)
	requried for service
	LEFT:
	Min 18” (457 mm)	FRONT:
	requried for service
		42” (1067 mm)
	Note: Observe requirements for 39” (914 mm) operating clearance

on either Left or Rear coil opening.

Fig. 4 — Service Clearance Dimensional Drawing

Step 2 — Complete Pre-Installation Checks

CHECK UNIT ELECTRICAL CHARACTERISTIC — Confirm before installation of unit that voltage, amperage and circuit protection requirements listed on unit data plate agree with power supply provided.

UNCRATE UNIT — Remove unit packaging except for the top skid assembly, which should be left in place until after the unit is rigged into its final location.

INSPECT SHIPMENT — File a claim with shipping company if the shipment is damaged or incomplete.

CONSIDER SYSTEM REQUIREMENTS

•Consult local building codes and National Electrical Code (NEC, U.S.A.) for special installation requirements.

•Allow sufficient space for airflow clearance, wiring, refrigerant piping, and servicing unit. See Fig.1 for unit dimensions and weight distribution data.

•Locate the unit so that the outdoor coil (condenser) airflow is unrestricted on all sides and above.

•The unit may be mounted on a level pad directly on the base channels or mounted on raised pads at support points. See Tables 1A and 1B for unit operating weights. See Fig. 1 for weight distribution based on recommended support points.

NOTE: If vibration isolators are required for a particular installation, use the data in Fig. 1 to make the proper selection.

Step 3 — Prepare Unit Mounting Support

Slab Mount

Provide a level concrete slab that extends a minimum of 6 in. (150 mm) beyond unit cabinet. Install a gravel apron in front of condenser coil air inlet to prevent grass and foliage from obstructing airflow.

Step 4 — Rig and Mount the Unit

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment damage.

All panels must be in place when rigging. Unit is not designed for handling by fork truck.

.

RIGGING — These units are designed for overhead rigging. Refer to the rigging label for preferred rigging method. Spreader bars are not required if top crating is left on the unit. All panels must be in place when rigging. As further protection for coil faces, plywood sheets may be placed against the sides of the unit, behind cables. Run cables to a central suspension point so that the angle from the horizontal is not less than 45 degrees. Raise and set the unit down carefully.

If it is necessary to roll the unit into position, mount the unit on longitudinal rails, using a minimum of 3 rollers. Apply force to the rails, not the unit. If the unit is to be skidded into position, place it on a large pad and drag it by the pad. Do not apply any force to the unit.

Raise from above to lift the unit from the rails or pad when unit is in its final position.

After the unit is in position, remove all shipping materials and top crating.

Step 5 — Complete Refrigerant Piping Connections

Refrigerant lines must be carefully designed and constructed to ensure equipment reliability and efficiency. Line length, pressure drop, compressor oil return, and vertical separation are several of the design criteria that must be evaluated. See Table 2.

IMPORTANT: Do not bury refrigerant piping underground.

IMPORTANT: A refrigerant receiver is not provided with the unit. Do not install a receiver.

7

Table 2 — 38AUQ*07-12 Piping Recommendations (Single-Circuit Unit)

R-410A				Equivalent Length
	Ft	0-38		38-75		75-113		113-150
Model	Length Linear	0-25		25-50		50-75		75-100
Nominal Capacity	Length Equiiv	0-38		38-75		75-113		113-115
38AUQ*07	Liquid Line	3/8		3/8		3/8	1/2	3/8	1/2
	Max Lift	25		50		48	75	39	100
	Cool
	Heat	25		50		46	60	31	60
	Suction Line	7/8		7/8		1-1/8		1-1/8
	Charge (lbs)	17.8		18.8		20.3	22.6	21.4	24.5
38AUQ*08	Liquid Line	1/2		1/2		1/2		1/2
	Max Lift	25		50		75		100
	Cool
	Heat	25		50		60		60
	Suction Line	7/8	1-1/8	1-1/8		1-1/8		1-1/8
	Charge (lbs)	20.9		23.0		24.9		26.8
38AUQ*12	Liquid Line	1/2		1/2		1/2		1/2	5/8
	Max Lift	25		50		75		85	100
	Cool
	Heat	25		50		60		60	60
	Suction Line	7/8	1-1/8	1-1/8		1-1/8		1-1/8	1-3/8
	Charge (lbs)	26.8		28.8		30.7		33.4	37.2
Legend:
Length Equiv	Equivalent tubing length, including effects of refrigeration specialties devices
Liquid Line	Tubing size, inches OD.
Max Lift	Maximum liquid lift at maximum permitted liquid line pressure drop
Cooling	• Indoor unit ABOVE outdoor unit
Heating	• Indoor unit BELOW outdoor unit
Suction Line	Tube size, inches OD
Charge	Charge Quantity, lbs. Calculated for both liquid line sizes (where applicable), but only with larger
	suction line size (where applicable)
NOTE:	For applications with linear length greater than 100 ft (30.5 m), contact your local Carrier representative.

CHECK VERTICAL SEPARATION — If there is any vertical separation between the indoor and outdoor units, check to ensure that the separation is within allowable limits. Relocate equipment if necessary.

PROVIDE SAFETY RELIEF — If local codes dictate an additional safety relief device, purchase locally and install locally. Installation will require the recovery of the factory shipping charge before the factory tubing can be cut and the supplemental relief device is installed.

REFRIGERANT LINE SIZING — Consider the length of the piping required between the outdoor and indoor units. The maximum allowable line length is 100 ft (30.5 m). See Table 2. Refrigerant vapor piping should be insulated.

IMPORTANT: A refrigerant receiver is not provided with the unit. Do not install a receiver.

INSTALL FILTER DRIER(S) AND MOISTURE INDICATOR(S) — Every unit MUST have a bi-directional filter drier in the liquid line. Locate the filter drier at the indoor unit, close to the evaporator coil’s thermal expansion valve (TXV) inlets.

38AUQ units include one Puron-duty filter drier, shipped in cartons attached to the unit basepan. Remove the filter drier and prepare to install in the liquid line at the evaporator coil. Do not remove connection fitting plugs until ready to connect and braze the filter drier into the liquid line position.

Table 4 — Puron-duty Filter Drier(s)

	Model-Size	Qty	Liquid	Desiccant	Part
			Line OD	Volume	Number Ref
	38AUQ*07	1	3/8-in	8 cu. in.	KH43LG091
	38AUQ*08	1	1/2-in	16 cu. in.	KH43LG085
	38AUQ*12	1	1/2-in	16 cu. in.	KH43LG085

Table 3 — Maximum Vertical Separation*

UNIT 38AUQ	UNIT 40RUQ	DISTANCE FT (M)
		Unit 38AUQ
		Above Unit 40RMQ
07	07	50 (15.2)
08	08	60 (18.3)
12	12	60 (18.3)

*Vertical distance between indoor and outdoor units.

Installation of liquid line moisture indicating sightglass in each circuit is recommended. Locate the sightglass(es) between the outlet of the filter drier and the TXV inlet.

Refer to Table 5 for recommendations on refrigeration specialties.

Select the filter drier for maximum unit capacity and minimum pressure drop. Complete the refrigerant piping from the indoor unit to the outdoor unit before opening the liquid and suction lines at the outdoor unit.

8

Table 5 — Refrigerant Specialties Part Numbers.

	LIQUID LINE		LIQUID LINE	LLSV	SIGHT	FILTER
	SIZE (in.)		SOLENOID VALVE (LLSV)	COIL	GLASS	DRIER
	3/8		ALC-066208	AMG-24/50-60	HMI-1TT3	Provided with unit
	1/	2	ALC-066209†	AMG-24/50-60	HMI-1TT4
						See Table 4
	5/8		ALC-066212	AMG-24/50-60	HMI-1TT5
	† 38AUD units require TWO sets of parts.

INSTALL LIQUID LINE SOLENOID VALVE —

It is recommended that a bi-directional solenoid valve be placed in the main liquid line (see Figs. 5 & 6) between the outdoor unit and the indoor coil. Locate the solenoid valve at the end of the liquid line, near the outdoor unit connections, with flow direction arrow pointed at the outdoor unit. Refer to Table 5. (A liquid line solenoid valve is required when the liquid line length exceeds 75 ft [23 m].) This valve prevents refrigerant migration (which causes oil dilution) to the compressor during the off cycle, at low outdoor ambient temperatures. Wire the solenoid according to the unit label diagram.

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment damage.

Failure to use a solenoid valve relay (SUR) accessory may cause overload of Comfort Alert Diagnostic Module (CADM) and compressor alarm lock out.

CAPACITY CONTROL LIQUID LINE SOLENOID VALVE Evaporator capacity control via liquid solenoid valve is not recommended for use with 38AUQ models.

	TXV		EQUALIZER LINE
INDOOR
	SENSING		SIGHT GLASS
COIL CKT	BULB
			A LOCATION
			FILTER DRIER
			A LOCATION
AIRFLOW	15 DIAMS		TXV
		10
	MIN
		DIAMS
		8 DIAMS	FLOW
		MIN
			LIQUID
			LINE
			SOLENOID
			VALVE

LEGEND

TXV — Thermostatic Expansion Valve

Fig.5 — Location of Sight Glass(es) and Filter Driers (typical 38AUQ/40RUQ size 07 & 08 systems)

	TXV		EQUALIZER LINE
INDOOR
	SENSING
COIL CKT 2	BULB
				SIGHT GLASS
			TXV	LOCATION
AIRFLOW	15 DIAMS			FILTER DRIER
		10	CKT 2	LOCATION
	MIN
		DIAMS	8 DIAMS
			MIN
	TXV			FLOW
INDOOR	SENSING			LIQUID
COIL CKT 1	BULB			LINE
				SOLENOID
				VALVE
AIRFLOW	15 DIAMS		TXV
		10	CKT 1
	MIN
		DIAMS
			8 DIAMS
			MIN

LEGEND

TXV — Thermostatic Expansion Valve

Fig.6 — Location of Sight Glass(es) and Filter Driers (typical 38AUQ/40RUQ size 12 system)

Table 6 — Minimum Outdoor Air Operating Temperature

	%	MINIMUM OUTDOOR
		TEMP — F (C)*
UNIT	COMPRESSOR
	CAPACITY	Standard Unit	Head Pressure
			Control†
38AUQ07		35 (1.7)	–20 (–28.9)
38AUQ08	100	35 (1.7)	–20 (–28.9)
38AUQ12		35 (1.7)	–20 (–28.9)

*Applies to Cooling mode of operation only.

†Wind baffles (field-supplied and field-installed) are recommended for all units with low ambient head pressure control. Refer to Low Ambient Control Installation Instructions (shipped with accessory) for details.

Table 7 — Insulation for Vapor Line Exposed to Outdoor Conditions

	LENGTH OF EXPOSED		INSULATION THICKNESS†
	VAPOR LINE*
	ft	m	in.	mm
	10	3	3/8	10
	25	8	1/2	13
	35	11	3/4	19
	50	15	3/4	19

*Recommended vapor line insulation for piping exposed to outdoor conditions to prevent loss of heating during heating cycle. When vapor line goes through interior spaces, insulation should be selected to prevent condensation on cooling cycle. Heating capacity should be reduced 1000 Btuh (295 W) if over 35 ft (11 m) of vapor line with 3/4 in. (19 mm) insulation is exposed to outdoor conditions.

†Closed cell foam insulation with a thermal conductivity of: 0.28 Btu

• in./ft2 • h • °F (0.04 W/m • °C).

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MAKE PIPING CONNECTIONS — Piping connections at the 38AUQ unit are ball valves with stub tube extensions. Do not open the unit service valves until all interconnecting tube brazing as been completed.

The stub tube connections include ¼-in SAE service fittings with Schrader valve cores (see Fig. 7). Before making any brazed connections to the unit service valves, remove both Schrader valve caps and cores and save for re-installation. Connect a source for nitrogen to one of these service fittings during tube brazing to prevent the formation of copper oxides inside the tubes at brazed joints.

		Field Service
	Factory	Access Port
		(Schrader core)
	High-Flow
	Access Port
	Service Valve
	with Stem Cap	Sweat
		Connection

Fig. 7 — Typical Piping Connection Assembly

When connecting the field tubing to the 38AUQ service valves, wrap the valves in wet rags to prevent overheating

Pressure-test all joints from outdoor unit connections over to the indoor coil, using nitrogen as pressure and with soap-and- bubbles.

When pressure-testing is completed, remove the nitrogen source at the outdoor unit service valves and re-install the two Schrader valve cores. Torque the cores to 2-3 in-lbs (23-34 N-cm).

Where vapor line is exposed to outdoor air, line must be insulated. See Table 7 for insulation requirements.

EVACUATION/DEHYDRATION — Evacuate and dehydrate the connected refrigeration system(s) (excluding the 38AUQ unit) to 500 microns using a two-stage vacuum pump attached to the service ports outside the 38AUQ service valves, following description in GTAC II, Module 4, System Dehydration.

UNIT OPERATION AND SAFETY HAZARD

Failure to follow this warning could cause personal injury, death and/or equipment damage.

Puron® (R-410A) refrigerant systems operate at higher pressures than standard R-22 systems. Do not use R-22 service equipment or components on Puron refrigerant equipment.

IMPORTANT: Charge in Cooling mode only!

PRELIMINARY CHARGE — Before starting the unit, charge R-410A liquid refrigerant into the high side of each 38AUQ circuit through the liquid service valve(s). The amount of refrigerant added must be at least 80% of the operating charge listed in Table 2 for LINEAR line length LESS the factory charge quantity (if factory shipping charge has not been removed). See the following example.

Allow high and low side pressures to equalize. If pressures do not equalize readily, charge R-410A vapor (using special service manifold with expansion device) into the suction line service port for the low side of system to assure charge in the evaporator. Refer to GTAC II, Module 5, Charging, Recover, Recycling, and Reclamation for liquid charging procedures.

Example:

38AUQ*08

60-ft (18.3 m) linear line length Equivalent line length 90-ft (27.4 m) Liquid Lift: 20-ft (6.1 m)

Select line sizes from Table 2 (38AUQ): Liquid 1/2 in

Suction 1-1/8 in.

Charge 23.0 lbs (at 75-ft linear length) 80% of Operating Charge:

0.80 x 23.0 = 17.6 lbs

Factory Shipping Charge: 12 lbs

Field-charge quantity: 17.6 lbs –12.0 lbs = 5.6 lbs

For linear line lengths longer than 100 ft (30.5 m), contact your local Carrier representative for system charge value.

Step 6 — Install Accessories

Accessories requiring modifications to unit wiring should be completed now. These accessories may include Winter Start controls, Low Ambient controls, phase monitor, Compressor LOCout. Refer to the instructions shipped with the accessory.

Step 7 — Complete Electrical Connections

ELECTRICAL SHOCK HAZARD

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

Do not use gas piping as an electrical ground. Unit cabinet must have an uninterrupted, unbroken electrical ground to minimize the possibility of personal injury if an electrical fault should occur. This ground may consist of electrical wire connected to unit ground lug in control compartment, or conduit approved for electrical ground when installed in accordance with NEC (National Electrical Code); ANSI/ NFPA 70, latest edition (in Canada, Canadian Electrical Code CSA [Canadian Standards Association] C22.1), and local electrical codes.

NOTE: Check all factory and field electrical connections for tightness. Field-supplied wiring shall conform with the limitations of 63°F (33°C) rise.

Field Power Supply —

If equipped with optional Powered Convenience Outlet: The power source leads to the convenience outlet's transformer primary are not factory connected. Installer must connect these leads according to required operation of the convenience outlet. If an always-energized convenience outlet operation is desired, connect the source leads to the line side of the unit-mounted disconnect. (Check with local codes to ensure this method is acceptable in your area.) If a de-energize via unit disconnect switch operation of the convenience outlet is desired, connect the source leads to the load side of the unit disconnect. On a unit without a unit-mounted disconnect, connect the source leads to compressor contactor C and indoor fan contactor IFC pressure lugs with unit field power leads.

All units except 208/230-v units are factory wired for the voltage shown on the nameplate. If the 208/230-v unit is to be connected to a 208-v power supply, the control transformer must be rewired by moving the black wire with the 1/4-in. female spade connector from the 230-v connection and moving it to the 208-v 1/4-in. male terminal on the primary side of the transformer. Refer to unit label diagram for additional information.

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Field power wires are connected to the unit at line-side pressure lugs on compressor contactor C and TB1 (see wiring diagram label for control box component arrangement) or at facto- ry-installed option non-fused disconnect switch. Max wire size is #4 AWG (copper only).

NOTE: TEST LEADS - Unit may be equipped with short leads (pigtails) on the field line connection points on contactor C or optional disconnect switch. These leads are for factory run-test purposes only; remove and discard before connecting field power wires to unit connection points. Make field power connections directly to line connection pressure lugs only.

FIRE HAZARD

Failure to follow this warning could result in intermittent operation or performance satisfaction.

Do not connect aluminum wire between disconnect switch and condensing unit. Use only copper wire.

(See Fig. 8.)

ELECTRIC

DISCONNECT

SWITCH

COPPER

WIRE ONLY

ALUMINUM

WIRE

Fig. 8 — Disconnect Switch and Unit

Units Without Factory-Installed Disconnect —

When installing units, provide a disconnect switch per NEC (National Electrical Code) of adequate size. Disconnect sizing data is provided on the unit informative plate. Locate on unit cabinet or within sight of the unit per national or local codes. Do not cover unit informative plate if mounting the disconnect on the unit cabinet.

Units with Factory-Installed Disconnect —

The factory-installed option disconnect switch is located in a weatherproof enclosure located under the main control box. The manual switch handle is accessible through an opening in the access panel.

All units -

All field wiring must comply with NEC and all local codes. Size wire based on MCA (Minimum Circuit Amps) on the unit informative plate. See Fig. 9 for power wiring connections to the unit power terminal block and equipment ground. Maximum wire size is #4 ga AWG per pole.

Provide a ground-fault and short-circuit over-current protection device (fuse or breaker) per NEC Article 440 (or local codes). Refer to unit informative data plate for MOCP (Maximum Over-current Protection) device size.

Units Without Disconnect Option

C TB1

11 13

Disconnect per NEC

L1 L2 L3

208/230-3-60 460-3-60 575-3-60

Units With Disconnect Option

	L1	2		1
			Optional		Factory
	L2	4	Disconnect	3
					Wiring
			Switch
	L3	6		5

Disconnect factory test leads; discard.

Fig. 9 — Power Wiring Connections

All field wiring must comply with the NEC and local requirements.

Voltage and Current Balance -

Voltage to compressor terminals during operation must be within voltage range indicated on unit nameplate. See Table 10. On 3-phase units, voltages between phases must be balanced within 2% and the current within 10%. Use the formula shown in the legend for Table 8, Note 5 (see page 14) to determine the percent of voltage imbalance. Operation on improper line voltage or excessive phase imbalance constitutes abuse and may cause damage to electrical components. Such operation would invalidate any applicable Carrier warranty.

Convenience Outlets

ELECTRICAL OPERATION HAZARD

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

Units with convenience outlet circuits may use multiple disconnects. Check convenience outlet for power status before opening unit for service. Locate its disconnect switch, if appropriate, and open it. Tag-out this switch, if necessary.

Two types of convenience outlets are offered on 38AUQ models: Non-powered and unit-powered. Both types provide a 125-volt GFCI (ground-fault circuit-interrupter) duplex receptacle rated at 15-A behind a hinged waterproof access cover, located on the end panel of the unit. See Fig. 10.

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