Carrier 38AK024-044 User Manual

5 (1)

HEATING A COOLING

38AK024-044 Air-Cooled Condensing Units

Installation, Start-Up and Service Instructions

50and 60-Hertz Air-Cooled Packages

CONTENTS

 

Page

SAFETY CONSIDERATIONS .........................................

1

BEFORE INSTALLATION.............................................

1-3

Rigging ...........................................................................

l

Placing Unit ..................................................................

3

Mounting Unit...............................................................

3

Compressor Mounting .................................................

3

INSTALLATION ..........................................................

3-10

Refrigerant Piping Connections ..................................

3

Single Pumpout Control...............................................

3

Filter Drier and Moisture Indicator...............................

3

Receiver .........................................................................

3

Piping Procedure ...........................................................

3

Power Supply .................................................................

5

Power Wiring..................................................................

5

START-UP ................................................................

11-16

Initial Check...................................................................

11

Leak Test and Dehydration .........................................

11

Preliminary Charge ......................................................

11

Start Unit .......................................................................

11

SAFETY CONSIDERATIONS

Installing, starting up and servicing air conditioning equipment can be hazardous due to system pressures, electrical components and equipment location (roofs, ele­ vated structures, etc.)

Only trained, qualified installers and service mechanics should install, start-up and service this equipment (Fig. 1).

Untrained personnel can perform basic maintenance functions such as cleaning coils. All other operations should be performed by trained service personnel.

When working on the equipment, observe precautions in the literature and on tags, stickers and labels attached to the equipment.

Follow all safety codes.

Wear safety glasses and work gloves.

Keep quenching cloth and fire extinguisher nearby when brazing.

Use care in handling, rigging and setting bulky equipment.

See Table 1 for Physical Data.

Cm

ELECTRIC SHOCK HAZARD

Open all remote disconnects before

tr

servicing this equipment.

 

 

 

 

Page

Charge System .........................................................

11

Operation ..................................................................

11

Timer Functions ........................................................

16

Sequence of Operation.............................................

16

Complete Unit Stoppage .........................................

16

SERVICE ..............................................................

17-19

Access for Servicing ................................................

17

Fan Adjustment ........................................................

18

Oil Charge .................................................................

18

Liquid Shutoff/Charging Valve ...............................

18

Capacity Control .......................................................

18

Oil Pressure Safety Switch (OPS) ..........................

19

Compressor Protection............................................

19

High-Pressure Switch ..............................................

19

Low-Pressure Switch ...............................................

19

Winter Start Control .................................................

19

Head Pressure Control............................................

19

TROUBLESHOOTING

.20

BEFORE INSTALLATION

Rigging — Preferred method is with spreader bars from above the unit. Use 2-in. (50 mm) OD pipe or hooks in lifting holes. Rig with 4 cables and spreader bars. All panels must be in place when rigging. See rigging label on unit for details concerning shipping weights, distance between lifting holes, center of gravity and spreader bar dimensions. See Fig. 2.

If overhead rigging is not possible, place chiller on skid or pad for rolling or dragging. When rolling, use minimum 3 rollers. When dragging, pull the pad. Do not apply force to the unit When in final position, raise from above to lift unit off pad.

A CAUTION

All panels must be in place when rigging. Do not fork units if no skid is supplied. If unit has skid, truck from sides only.

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obiigations.

Book 1

PC111

Catalog No 563-915

Printed in U S A

Form 38AK-1SIM

Pgi

11-89

Replaces: New

Tab I 3a

 

 

 

 

 

 

 

3/4-IN (19mm) NOTCHES

IN END OR SPREADERS

Fig. 1 - Model 38AK (024 shown)

Fig. 2 — Rigging with Spreader Bars (Field Supplied)

Table 1A — Physical Data — 60 Hertz

UNIT 38AK

024

028

034

044

 

COMPRESSOR

 

 

Reciprocating Semi-Hermetic

 

 

 

 

No. ...Type

1 06E4250

 

1 06E9265

 

 

1 06E9275

 

 

1 06E9299

No. Cyls (ea) ...Speed, Rpm (r/s)

4 1750(29)

 

 

6 1750(29)

 

 

 

 

Capacity Steps

2

 

 

3

 

 

 

 

Oil Charge*, Pt (L)

14(66)

 

 

19(9)

 

 

 

 

Oil Pressure Switch Setting (psid)

 

 

 

180

 

 

 

 

Crankcase Heater (watts)

 

 

 

 

 

 

 

Protection

 

 

 

See Note

 

 

 

 

Capacity Control

 

 

Suction Pressure Unloader(s)

 

 

 

 

No. 1

76

 

Unloader Settings (psig)

76

 

Load

76

76

 

Unload

58

58

58

58

 

No. 2

 

 

Unloader Settings (psig)

 

 

 

 

Load

78

 

78

 

78

 

Unload

60

 

60

 

60

 

REFRIGERANT CHG, R-22

28 (12 7)

305(138)

 

435(19.7)

 

65(295)

 

Approximate lb (kg)

 

 

 

CONDENSER FANS, Type

 

 

Propeller Type, Direct Driven

3 ...30 (762)

 

No. ...Diameter, in. (mm)

10,600 (5,000)

2 30(762)

 

 

 

 

Total Airflow, Cfm (L/s)

15,700 (7,400)

23,700(11,200)

 

Speed, Rpm (r/s)

 

 

 

1140(19)

 

 

 

 

CONDENSER COIL, Type

3 ... 17 (1 49)

 

Horizontal, Plate Fin

3 17(149)

 

Rows...Fins/in. (Fin Spacing mm)

2 19(134)

39 2(364)

 

Total Face Area, sq ft (m‘)

235(218)

 

 

584(543)

 

Table IB — Physical Data — 50 Hertz

 

 

 

 

UNIT 38AK

024

 

028

 

 

034

044

 

COMPRESSOR

1 06E4250

 

Reciprocating, Semi-Hermetic

 

 

 

 

No.... Type

 

1 06E9265

 

 

1 06E9275

 

 

1 06E9299

No. Cyls (ea)... Speed, Rpm (r/s)

4 1450(24 2)

 

 

6 1450(24 2)

 

 

 

 

Capacity Steps

2

 

 

3

 

 

 

 

Oil Charge*, Pt (L)

14(66)

 

 

19(9)

 

 

 

 

Oil Pressure Switch Setting (psid)

 

 

 

c

 

 

 

 

Crankcase Heater (watts)

 

 

 

180

 

 

 

 

Protection

 

 

 

See Note

 

 

 

 

Capacity Control

 

 

Suction Pressure Unloader(s)

 

 

 

 

No. 1

76

 

Unloader Settings (psig)

76

 

Load

76

76

 

Unload

58

58

58

58

 

No. 2

 

 

Unloader Settings (psig)

 

 

 

 

Load

 

78

 

78

 

78

 

Unload

 

60

 

60

 

60

 

REFRIGERANT CHG., R-22

28(12 7)

 

305(13.8)

 

 

435(197)

 

 

65(295)

 

Approximate lb (kg)

 

 

 

 

CONDENSER FANS, Type

 

 

Propeller Type, Direct Driven

3... 30 (762)

 

No.... Diameter, in. (mm)

10,600 (5,000)

2 30 (762)

 

 

 

 

Total Airflow, dm (L/s)

15,700 (7,400)

23,700 (11,200)

 

Speed, Rpm (r/s)

 

 

 

950 (15 8)

 

 

 

 

CONDENSER COIL, Type

3... 17 (149)

 

Horizontal, Plate Fin

3. 17(149)

 

Rows ... Fins/in. (Fin Spacing mm)

2 19(134)

39.2(364)

 

Total Face Area, sq ft (m‘)

235(218)

 

 

584(543)

 

*See Service, Oil Charge, for Carrier-approved oil

NOTE: Circuit breaker in main power circuit and discharge gas thermostat in control circuit

Paid - pounds per sq in differential

 

 

 

 

 

 

 

 

 

 

2

Placing Unit — There must be 4 ft (1220 mm) for service and for unrestricted airflow on all sides of unit, and a minimum of 8 ft (2440 mm) clear air space above unit. For multiple units, allow 8 ft separation between units for airflow and service.

Mounting Unit — When unit is in proper location, use of mounting holes in base rails is recommended for securing unit to supporting structure, or for mounting unit on vibration isolators if required. Fasteners for mounting unit are field supplied. Be sure to mount unit level to ensure proper oil return to compressors.

Compressor Mounting — As shipped, compressor is held down by 4 bolts. After unit is installed loosen each bolt until the snubber washer can be moved with finger pressure. See Fig. 3.

INSTALLATION

Refrigerant Piping Connections — Line sizes depend on length of piping required between condensing unit and evaporator. See Table 2. It is important to consider liquid lift and compressor oil return. Refer to Part 3 of Carrier System Design Manual for line sizing information, and Fig. 4 for recommended piping details.

Single Pumpout Control — All units are factory wired to operate on single pumpout control. A factory-supplied liquid line solenoid valve must be installed in the liquid line ahead of the indoor coil. See Fig. 5. Wires from solenoid valve must be in conduit, and a ground wire must be provided to comply with codes.

A WARNING

Failure to properly install liquid line solenoid at the indoor unit as described, without Carrier author­ ization, may VOID warranty.

If unit is used with a chiller, wiring modifications may be required.

Filter Drier And Moisture Indicator — Every unit should have a filter drier and a sight glass (moisture indicator) field installed. Select the filter drier for maximum unit Capacity and minimum pressure drop. Figure 5 shows recommended locations of filter drier(s) and sight glass. Complete the refrigerant piping from the evaporator to the condenser before opening the liquid and suction lines at the condensing unit. One filter drier may be installed at location A in Fig. 5, or 2 filter driers may be installed at locations B.

FACTORY SUPPLIED

FIELD SUPPLIED

SOLENOID VALVE

CAPACITY CONTROL

NOTES:

1Suction line is connected to coil on same side as the entering air.

2For coils having only one section, use upper section piping; for coiis having 2 sections, use upper and middle section piping

3Lower section is first on and last off.

4For more complete piping information, refer to Carrier System Design Manual, Part 3

Fig. 5 — Liquid Line Solenoid Valve,

Filter Drier(s) and Sight Glass Locations

Receiver — No receiver is provided with the unit; it is recommended that one not be used.

Piping Procedure — Do not remove run-around pipe from suction and liquid line stubs until piping connections are ready to be made. Pass nitrogen or other inert gas through piping while brazing, to prevent formation of copper oxide.

Install field-supplied thermostatic expansion valve in liquid line ahead of each evaporator section. For 2-step cooling, the fleld-supplkd solenoid used must be wired to be opened by control from a 2-step thermostat

Fig. 4 — Suction Line Piping to Unit with 3 Section Coil Split

For example: 2 solenoids may be used with 3 TXVs —one of the solenoids serving a liquid line feeding 2 of the TXVs.

Table 2 — Refrigerant Piping Sizes

SINGLE SUCTION RISERS

MODEL

 

 

 

LENGTH OF INTERCONNECTING PIPING (FT)

 

 

 

16-25

 

26-50

 

51-75

 

76-100

 

101-200

38AK

 

 

 

 

 

 

 

 

 

 

L

S

L

S

L

S

L

S

L

S

 

024

5/8

1-5/8

7/8

1-5/8

7/8

2-1/8

7/8

2-1/8

7/8

2-1/8

028

7/8

1-5/8

7/8

2-1 /8

7/8

2-1/8

7/8

2-1/8

7/8

2-1/8

034

7/8

2-1 /8

7/8

2-1/8

7/8

2-1/8

1-1 /8

*

1-1/8

*

044

7/8

2-1/8

7/8

2-1/8

1-1/8

*

1-1/8

*

1-1/8

*

L-Liquid Line

S-Suction Line

 

 

 

 

 

 

 

 

* IMPORTANT — Requires a double suction riser, see below:

NOTE: Liquid and suction iine sizes are OD (in)

 

 

 

 

 

 

MAXIMUM LIQUID LIFT

 

 

 

 

 

 

 

 

UNIT 38AK

 

 

60 Hz

 

 

 

50 Hz

 

 

 

 

 

 

 

 

Ft

 

M

 

 

Ft

 

M

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

024

 

86

 

26

 

 

72

 

21

 

 

 

 

 

 

028

 

76

 

23

 

 

66

 

20

 

 

 

 

 

 

034

 

67

 

20

 

 

60

 

18

 

(A)

- SUCTION RISER WITHOUT TRAP

 

 

044

 

76

 

23

 

 

66

 

20

 

(B)

- SUCTION RISER WITH TRAP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(^- SUCTION LINE TO CONDENSING UNIT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DOUBLE SUCTION RISERS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LENGTH OF INTERCONNECTING PIPING (FT)

 

 

 

 

MODEL

 

51-75

 

 

76-100

 

 

 

 

 

 

101-200

 

 

 

38AK

A

B

C

A

B

 

C

 

A

 

B

 

C

 

034

2-1/8

1-5/8

2-5/8

1-5/8

2-1/8

 

2-5/8

 

1-5/8

 

2-1/8

 

2-5/8

 

044

1-5/8

2-1/8

 

2-5/8

 

1-5/8

 

2-1/8

 

2-5/8

NOTE: A, B, C dimensions relate to reference diagram

SUCTION PIPING AT EVAPORATOR AND TXV BULB LOCATION (See Fig. 5)

The purpose of these recommendations is to achieve good mixing of the refrigerant leaving the evaporator suction header for proper sensing by the TXV bulb.

1.A minimum of two 90° elbows must be installed upstream of the expansion valve bulb location.

2.The TXV sensing bulb should be located on a vertical riser where possible. If a horizontal location is neces­ sary, secure the bulb at approximately the 4 o’clock position.

3.Size the suction line from the evaporator through the riser for high velocity. Enter the suction pipe sizing charts in the Carrier System Design Manual at design tons and equivalent length (for 2 degree F loss). If reading falls between 2 sizes on chart, choose the smaller pipe size.

Suction piping for the high velocity section should be selected for about 0.5 degree F friction loss. If a 2 degree F loss is allowed for the entire suction line, 1.5 degree F is left for the balance of the suction line and it should be sized on that basis. Check that the high-velocity sizing is adequate for oil return up the riser.

If an oil return connection at the bottom of this suction header is supplied with an evaporator, this connection must be teed-in ahead of first mixing elbow. When the compressor is below the evaporator, the riser at the evaporator does not have to extend as high as the top level. After a 15-diameter riser has been provided, the suction line may elbow down immediately.

SAFETY RELIEF — A fusible plug is located on unit liquid line before the liquid valve.

Power Supply — Electrical characteristics of available power supply must agree with unit nameplate rating. Supply voltage must be within limits shown in Table 3.

IMPORTANT: Operating unit on improper supply voltage, or with excessive phase imbalance, constitutes abuse and may affect Carrier warranty. See Unbal­ anced 3-Phase Supply Voltage, page 6.

Power Wiring — All power wiring must comply with applicable local and national codes. Install field-supplied branch circuit fused disconnect(s) per NEC (National Electri­ cal Code) of a type that can be locked OFF or OPEN. Disconnect(s) must be within sight from and readily acces­ sible from unit in compliance with NEC Article 440-14.

GENERAL WIRING NOTES

1.A crankcase heater is wired in the control circuit so it is always operable as long as power supply disconnect is on, even if any safety device is open or unit stop-start switch is off. It is protected by a 5-amp circuit breaker in control power.

2.The power circuit field supply disconnect should never be open except when unit is being serviced or is to be down for a

prolonged period When operation is resumed crankcase heater should be energtedfor 24 hours before start-up. If unit is to be shut down for a prolonged period it is recommended that the suction arid discharge valves be closed to prevent an excessive accumulation of refrigerant in the compressor oil

3. Power entry is at one end only.

Table 3 — Electrical Data

60 HERTZ

MODEL

 

 

UNIT

 

 

 

 

COMPRESSOR

FAN MOTORS!

Volts

SuDolied*

 

 

 

 

 

 

 

 

 

OfiAtr

MCA

 

MOCP

 

ICF

RLA

LRA

FLA (ea)

Qty

 

 

3 Ph, 60 Hz

Min.

Max.

 

 

(Fuse)

 

 

 

 

 

 

 

500

208/230

187

254

92.1

 

150

 

348.6

68

345

3.6

2

024

200

380

342

418

51 1

 

80

 

194.9

346

191

3.9

2

600

460

414

508

46.9

 

80

 

1748

34 7

173

1 8

2

 

100

575

518

632

42.9

 

70

 

123.4

28.9

120

3.4

2

 

500

208/230

187

254

124.6

 

200

 

452.2

89.8

446

6.2

2

028

200

380

342

418

64.7

 

110

 

250.9

45.5

247

3.9

2

600

460

414

508

60 7

 

100

 

226.1

43.6

223

31

2

 

100

575

518

632

52.5

 

80

 

167.4

36.5

164

3.4

2

 

500

208/230

187

254

145 5

 

250

 

512.2

106.5

506

6.2

2

034

200

380

342

418

72.5

 

125

 

283.9

52.6

280

3.9

2

600

460

414

508

687

 

110

 

256.1

50

253

3.1

2

 

100

575

518

632

54.9

 

90

 

179.4

38.5

176

3.4

2

 

500

230

187

254

2030

 

350

 

702.4

147 5

690

62

3

044

200

380

342

418

111 1

 

175

 

3898

79.5

382

39

3

600

460

414

508

91 0

 

150

 

351 2

65.4

345

3.1

3

 

100

575

518

632

81.5

 

125

 

282.8

57.1

276

3.4

3

 

 

 

 

 

 

50 HERTZ

 

 

 

 

 

MODEL

 

 

UNIT

 

 

 

 

COMPRESSOR

FAN MOTORS!

Volts

Supplied*

MCA

 

MOCP

 

ICF

RLA

LRA

FLA (ea)

Qty

38AK

 

 

3 Ph, 50 Hz

Min.

Max.

 

(Fuse)

 

 

 

 

 

 

 

 

 

 

 

024

800

230

198

254

88.1

 

125

 

256.4

60.3

250

6.4

2

300

346

311

380

50.5

 

80

 

2044

333

200

44

2

 

900

400

342

400

49.3

 

80

 

1740

347

173

1.0

2

028

800

230

198

254

109

 

175

 

348.4

76.9

342

64

2

300

346

311

380

64.9

 

100

 

263.4

44.9

259

4.4

2

 

900

400

342

400

605

 

100

 

226.0

436

223

30

2

034

800

230

198

254

1202

 

200

 

372.4

859

366

6.4

2

300

346

311

380

76.1

 

125

 

2984

539

294

4.4

2

 

900

400

342

400

68.5

 

110

 

2560

50.0

253

3.0

2

044

800

230

198

254

1506

 

250

 

5578

105.1

545

6.4

3

300

346

311

380

112.6

 

175

 

408.8

79.5

400

4.4

3

 

900

400

342

400

90.8

 

150

 

351 0

65.4

345

30

3

FLA — Full Load Amps

ICF — Maximum Instantaneous Current Flow during starting (the point in the starting sequence where the sum of the LRAfor the starting compressor, plus the total RLA for all running compressors, plus the total FLA for all running fan motors is maximum).

LRA — Locked Rotor Amps

MCA — Minimum Circuit Amps (complies with National Electrical

Code [NEC], Section 430-24)

MOCP — Maximum Overcurrent Protection

RLA — Rated Load Amps

*Units are suitable for use on electrical systems where voltage supplied to unit terminals is not below or above listed minimum and maximum limits

t All fans are protected by a single circuit breaker.

4.Maximum field wire sizes allowed by lugs on terminal block are:

350 MCM for models 38AK028 (208/230-3-60), 38AK034 (208/230-3-60, 230-3-50), and 38AK044 (208/230-3-60, 230-3-50)

2/0 AWG for all other models.

5.Terminals for field power supply are suitable for copper, copper-clad aluminum or aluminum conduc­ tors. Insulation must be rated 167 F (75 C) minimum.

CONDENSER FANS — The fans must rotate counter­ clockwise when viewed from above. If necessary, correct direction of fan rotation by interchanging any 2 power input wires at disconnect switch. Affix crankcase heater decal (located in installer’s packet) to unit disconnect switch.

FIELD CONNECTIONS

1.Main Power — Bring wires from the fused disconnect switch through hole in bottom rail of unit to control

box (Fig. 6, 7, 8) and connect terminals 1111, [12

13 on line side of terminal block TBl (see Fig. 9).

To comply with NEC Article 440-14, the disconnect must be located within sight from and readily acces­ sible from unit.

■ 2. 24-v Control Power — Units have single point power connections. Control circuit is directly connected inter­ nally to unit. Maximum 24-v control circuit is 3 amps.

NOTE: For wire runs up to 50 ft. use no. 18 AWG insulated wire (35 C min.). For 50 to 75 ft., use no. 16 AWG insulated wire (35 C min.). For over 75 ft. use 14 AWG insulated wire (35 C min.).

3.Control Circuit Interlock — An airflow switch may be installed in the indoor air handler to prevent unit from running when indoor air is not flowing. This switch (no. HR81JE001) is available from Service Parts Center, or equivalent can be field supplied. This should be electri­ cally interlocked in the control circuit, between term­

inals I 1 I and I 6 I (for flow switch) on TB2. See Fig.

9 for field wiring. This is in the 115-v circuit. Wires must be run in conduit with ground wire.

4.Transformer Connections — See unit wiring label dia­ gram, notes 1 and 2, located behind compressor com­ partment end access door.

IMPORTANT: Ensure power to the crankcase heater is always on (except when servicing the unit). If circuit breakers inside unit shut down the com­ pressor and condenser fans, crankcase heater remains on.

UNBALANCED 3-PHASE SUPPLY VOLTAGE — Never operate a motor where a phase imbalance in supply voltage is greater than 2%. Use the following formula to determine the % voltage imbalance:

% Voltage Imbalance I ^

= 100 X

max voltage deviation from average voltage

average voltage

 

Example: Supply voltage is 240-3-60.

AB = 243 volts

BC = 236 volts

AC = 238 volts

Average Voltage = 243 + 236 + 238 = 239 volts

Determine maximum deviation from average voltage:

(AB) 243 - 239 = 4 volts (BC) 239 - 236 = 3 volts (AC) 239 - 238 = 1 volt

Maximum deviation is 4 volts. Determine % voltage imbalance:

% Voltage Imbalance = 100 x —^ = 1.7% 239

This amount of phase imbalance is satisfactory as it is below the maximum allowable 2%.

IMPORTANT: Contact your local electric utility company immediately if the supply voltage phase imbalance is more than 2%.

Carrier 38AK024-044 User Manual

HINGED ACCESS DOOR•

NOTES:

1THERE MUST BE [1220 mm] 4 ft FOR SERVICE AND

FOR UNRESTRICTED AIRFLOW ON ALL SIDES OF UNIT.

THERE MUST BE MINIMUM C2440 mml 8 ft CLEAR AIR SPACE ABOVE UNIT.

3.THE APPROXIMATE OPERATING WEIGHT OF THE UNIT IS:

 

60 HZ

 

 

 

50 HZ

 

 

UNIT

WT LBSWT KG

UNIT

WT LBSWT KG

 

38AK024

1456

661

 

38AK024

1456

661

 

38AK024C 1580

717

 

38AK024C 1580

717

 

CONTROL BOX

- A

'II

NOTE: "C" INDICATES COPPER COIL.

APPROX. OPER. WT. (LB.)

 

2

4

 

 

 

AT SUPPORT POINTS

 

 

 

60 Hz

1

2

3

4

TOT.

 

 

024

411

501

245

299

1456

 

 

024C

448

533

273

326

1580

 

 

50 Hz

 

 

 

 

 

 

 

024

587

433

486

358

1864

 

 

024c

626

462

518

382

1988

 

 

 

 

 

 

 

 

[63.5-92.1] 2 1/2'-: FIELD MAIN POWE

HINGED AC

[1315] 4'-3 3/4'

[61] 2 7/16

[19.1]

3/4' DIA; MOUNTING HOLES (TYP 4 PLACES)

[63.5-92.1]

[22.2]

2 1/2'-3 5/8'DIA.

7/8' DIA.

FIELD POWER

FIELD CONTROL

ENTRY 8 LIFTING

POWER ENTRY

Fig. 6 — Dimensioi

ECimON

PAM No. 2

5/8' DIA.

LY TOP V I E W

[22.2] 7/8' DIA.

FIELD CONTROL CIRCUIT WIRING

10'-7 13/16'

S I D E V I E W

1 Drawing, 38AK024

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