Carrier 50ZHA024-060 Unit Controls, HIGH-PRESSURE Relief Valve, Sequence of Operation

Page 13

Table 7—Dry Coil Air Delivery* Horizontal Discharge

(Deduct 10 percent for 208 Volt Operation)

50ZHA

SPEED TAP

WATTS/C.F.M

 

 

 

EXTERNAL STATIC PRESSURE

 

 

 

0.1

0.2

.03

0.4

0.5

0.6

0.7

0.8

0.9

1.0

 

 

 

 

1

Watts

-

99

100

118

130

142

-

-

-

-

024

C.F.M.

-

848

793

757

698

632

-

-

-

-

 

2

Watts

-

-

-

-

-

222

233

244

257

260

 

 

C.F.M

-

-

-

-

-

970

918

861

795

729

 

 

 

2

Watts

-

155

146

157

170

-

-

-

-

-

030

C.F.M

-

1108

995

951

884

-

-

-

-

-

 

 

 

 

 

 

 

 

 

 

 

 

 

3

Watts

-

-

-

-

-

261

275

286

291

315

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C.F.M.

-

-

-

-

-

1117

1053

1014

980

877

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

Watts

180

166

179

191

204

216

-

-

-

-

 

 

 

 

 

 

 

 

 

 

 

 

036

C.F.M.

1344

1215

1172

1136

1095

1051

-

-

-

-

 

 

 

 

 

 

 

 

 

 

 

 

 

2

Watts

-

-

-

261

276

290

301

316

329

342

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C.F.M.

-

-

-

1343

1304

1272

1234

1190

1148

1100

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

Watts

269

283

305

321

336

349

360

-

-

-

 

 

 

 

 

 

 

 

 

 

 

 

042

C.F.M.

1440

1404

1369

1333

1301

1273

1239

-

-

-

 

 

 

 

 

 

 

 

 

 

 

 

 

4

Watts

-

-

418

432

450

465

480

490

503

518

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C.F.M.

-

-

1572

1543

1504

1475

1441

1418

1380

1332

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

Watts

204

209

216

229

236

249

 

 

 

 

 

 

 

 

 

 

 

 

 

C.F.M.

1129

1087

1027

994

932

881

 

 

 

2

Watts

233

245

254

266

276

289

048

C.F.M.

1164

1122

1066

1025

954

906

 

3

Watts

386

398

409

418

425

435

438

441

451

 

 

C.F.M.

1680

1652

1625

1583

1555

1515

1477

1444

1403

 

 

 

4

Watts

440

448

457

462

469

477

480

485

486

 

C.F.M.

1745

1717

1684

1651

1612

1573

1537

1508

1470

 

 

 

1

Watts

224

235

251

266

277

291

298

-

-

-

 

C.F.M.

1334

1288

1259

1224

1181

1157

1117

-

-

-

 

 

 

2

Watts

-

-

286

301

311

325

333

344

370

-

060

C.F.M.

-

-

1333

1296

1261

1232

1199

1170

1062

-

 

3

Watts

608

626

643

660

668

685

697

-

-

-

 

 

C.F.M.

1931

1900

1878

1844

1817

1789

1755

-

-

-

 

 

 

4

Watts

737

755

770

787

799

817

826

812

782

-

 

C.F.M.

2093

2061

2028

2001

1971

1934

1899

1850

1757

-

 

 

Air delivery values are based on operating voltage of 230-v., dry coil, without filter or electric heater. Deduct wet coil, filter, and electric heater pressure drops to obtain external static pressure availabe for ducting.

Do not operate the unit at a cooling airflow that is less than 350 cfm for each 12,000 Btuh of rated cooling capacity. Evaporator coil frosting may occur at airflows below this point.

Dashes indicate portions of the table that are beyond the blower motor capacity or are not recommended.

 

RATED AIRFLOW

HIGH AIRFLOW

SIZE

Low

High

Low

High

 

Stage

Stage

Stage

Stage

048

Tap 1

Tap 3

Tap 2

Tap 4

060

Tap 1

Tap 3

Tap 2

Tap 4

Step 5—Unit Controls

All compressors have the following internal-protection controls.

HIGH-PRESSURE RELIEF VALVE

This valve opens when the pressure differential between the low and high side becomes excessive.

LOSS OF CHARGE SWITCH

Located on the outdoor liquid line is a low-pressure switch which functions as a loss-of-charge switch. This switch contains a Schrader core depressor. This switch opens at 7 psig and closes at 22 psig. No adjustment is necessary.

COMPRESSOR OVERLOAD

This overload interrupts power to the compressor when either the current or internal temperature become excessive, and automati- cally resets when the internal temperature drops to a safe level.

This overload may require up to 60 minutes (or longer) to reset; therefore, if the internal overload is suspected of being open, disconnect the electrical power to the unit and check the circuit through the overload with an ohmmeter or continuity tester.

Step 6—Sequence of Operation

FAN OPERATION

The FAN switch on the thermostat controls indoor fan operation. When the FAN switch is placed in the ON position, the IFR (indoor-fan relay) is energized through the G terminal on the thermostat. The normally-open contacts close, which then provide power to the indoor (evaporator) fan motor (IFM). The IFM will run continuously when the FAN switch is set to ON.

When the FAN switch is set to AUTO, the thermostat deenergizes the IFR (provided there is not a call for cooling). The contacts open and the IFM is deenergized. The IFM will be energized only when there is a call for cooling, in heat pump heating mode or if the unit is equipped with accessory electric heat, the indoor-fan motor will also run while the accessory electric heat is energized.

NOTE: Some units are equipped with a time-delay relay. On these units, the indoor fan remains on for 30 seconds after G or Y is deenergized.

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Contents Safety Considerations Table of ContentsIntroduction Unit Base Dimensions, 50ZHA024-060 Unit Damage Hazard Unit SpecificationsProvide for Condensate Disposal Physical Data Install Electrical ConnectionsHIGH-VOLTAGE Connections Size PRE-START-UPRequired Subcooling Required Liquid Line TemperatureRequired Subcooling F C START-UP Start-Up Cooling Section and Make AdjustmentsCheck for Refrigerant Leaks Refrigerant ChargeFor 208/230-V Blower Motors Indoor Airflow and Airflow AdjustmentsSize Rated Airflow High Airflow Typical Unit Electrical Diagram Sizes A05200 Accessory Electric Heater Wiring Electrical Data-50ZHA HIGH-PRESSURE Relief Valve Unit ControlsSequence of Operation FAN OperationMaintenance Cooling Charging ChartAir Filter FIRE, EXPLOSION, Electrical SHOCK, CUT HAZ- ARDUnit Top Removal Outdoor-Coil Side Indoor Blower and MotorWet Coil Pressure Drop Accessory Electric Heat Pressure Drop In. wgFilter Pressure Drop in. wg START-UP Checklist TroubleshootingTypical Heat Pump Operation, Heating Mode Symptom Cause Remedy Troubleshooting-Cooling and HeatingII. PRE-START-UP Preliminary InformationIII. START-UP

50ZHA024-060 specifications

The Carrier 50ZHA024-060 is a remarkable rooftop unit designed for commercial applications, providing both cooling and heating solutions in a compact and efficient manner. Known for its reliability and advanced engineering, this model is ideal for businesses seeking to optimize indoor comfort while maintaining energy efficiency.

One of the key features of the 50ZHA unit is its advanced scroll compressor technology. This innovation not only ensures quiet operation but also offers superior efficiency, reducing operational costs. The unit is designed to deliver a wide range of capacity options, from 24,000 to 60,000 BTU/h, making it versatile for various building sizes and requirements.

The 50ZHA series employs a microprocessor-based control system that enhances user convenience and operational efficiency. This smart technology enables precise temperature control, scheduling, and diagnostics. Furthermore, it offers compatibility with advanced building management systems, allowing for seamless integration into modern HVAC setups.

Energy efficiency is a hallmark of the Carrier 50ZHA024-060, which is equipped with environmentally friendly refrigerants that meet current regulatory standards. This commitment to sustainability is further emphasized by its exceptional SEER and EER ratings, indicating lower energy consumption without compromising performance.

In terms of construction, the 50ZHA series features a robust design with corrosion-resistant materials, ensuring durability even in harsh environmental conditions. The unit’s compact rooftop design simplifies installation and reduces the footprint, making it an excellent choice for urban areas where space is limited.

Moreover, the Carrier 50ZHA models are equipped with advanced filtration systems that improve indoor air quality by minimizing airborne contaminants. This is particularly beneficial for commercial spaces, where maintaining a healthy environment is crucial for employee productivity and wellbeing.

The 50ZHA024-060 also offers various customizable options, including economizers for increased fresh air intake and enhanced humidity control features. These options allow businesses to tailor their HVAC solutions to specific operational needs, ensuring optimal comfort year-round.

In summary, the Carrier 50ZHA024-060 is an exceptional rooftop unit that combines advanced technology, energy efficiency, and user-friendly controls. Its sturdy construction, along with a range of customizable features, makes it a leading choice for commercial HVAC applications, ensuring sustained performance and comfort in diverse settings.