Carrier 48NLT User Manual

48NLT, NMT, NET, NHT AND NVT 018-060

HEATING & COOLING

Packaged Heating/Cooling Units

Installation, Start-Up and Service Instructions

CONTENTS

Page

SAFETY CONSIDERATIONS General

Job Data ..................................

RECEIVING AND INSTALLATION Step 1 — Check Equipment

• IDENTIFY MACHINE

• INSPECT SHIPMENT

Step 2 — Provide Unit Support

• ROOF CURB

• SLAB MOUNT

Step 3 — Provide Ciearances .................................4

Step 4 — Rig and Place Unit....................................4

Step 5 — Connect Condensate Drain Step 6 - instali Venting Step 7 - Instail Gas Piping Step 8 — Instail Duct Connections Step 9 - Instail Electrical Connections

• HIGH VOLTAGE CONNECTIONS

• SPECIAL PROCEDURES FOR 208-V

• CONTROL VOLTAGE CONNECTIONS

• HEAT ANTICIPATOR SETTING

• TRANSFORMER CIRCUIT PROTECTION

PRE-START-UP START-UP MAINTENANCE

NOTE TO INSTALLER — Before the installation, READ THESE INSTRUCTIONS CAREFULLY AND COM

PLETELY. Also, make sure the User’s Manual and Re placement Guide are left with the unit after installation.

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OPERATION

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SAFETY CONSIDERATIONS

Installation and servicing of air conditioning equipment can be hazardous due to system pressure and electrical com ponents. Only trained and qualified personnel should in stall, repair or service air conditioning equipment.

Untrained personnel can perform basic maintenance func tions of cleaning coils and filters. All other operations should be performed by trained service personnel. When working on air conditioning equipment, observe precautions in the literature, tags and labels attached to the unit and other safety precautions that may apply.

Follow all safety codes. Wear safety glasses and work gloves. Use quenching cloth for unbrazing operations. Have fire extinguisher available for all brazing operations.

A WARNING

Improper installation, adjustment, alteration, service, main

tenance or use can cause carbon monoxide poisoning, fire

or an explosion which can result in personal injury or

unit damage. Consult a qualified installer, service agency

or gas supplier for information or assistance. The quali

fied installer or agency must use only factory-authorized

kits or accessories when modifying this product.

. 1 . 1 . 1

1-10

. 1

6 6

7 8

10,11 11-20

20-26

________

Fig. 1 - Model 48NLT, NMT, NET, NHT and NVT

A WARNING

Before performing service or maintenance operations on unit, turn off unit main power switch. Electrical shock could cause personal injury.

General - The 48NLT, NMT, NET, NHT and NVT

units are fully self-contained, combination gas heating/ cooling units designed for outdoor installation. See Fig. 1. The units are shipped in a vertical configuration and may be installed either on a rooftop or converted to horizontal configuration when placed on a ground-level cement slab.

Job Data — Necessary information consists of:

machine location drawings, piping drawings, field wiring diagrams and rigging guide.

RECEIVING AND INSTALLATION

Step 1 — Check Equipment

IDENTIFY MACHINE — The machine model number and serial number are stamped on machine identification plate. Check this information against shipping papers and job data.

INSPECT SHIPMENT — Inspect for shipping damage while machine is still on shipping pallet. If machine appears to be damaged or is torn loose from its anchorage, have it exam ined by transportation inspectors before removal. Forward claim papers directly to transportation company. Manufac turer is not responsible for any damage incurred in transit.

Check all items against shipping list. Immediately notify the nearest Carrier Air Conditioning office if any item is missing.

To prevent loss or damage, leave all parts in original pack ages until installation.

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

Book|1 |4 PC 111 Catalog No 564-920 Printed in U.S,A. Form 48NT-20SI Pg 1 11-91 Replaces: 48NT-19SI

Tab la la

RIGHT SIDE VIEW

LEFT SIDE VIEW

Fig. 2 — 48 Dimensional Drawing, Sizes NLT018 — NET042

UNIT

48NHT036 48NVT036 48NHT042 48NVT042 48NLT048 48NMT048 48NHT048 48NVT048 48NLT060 48NMT060 48NHT060 48NVT060

ELECTRICAL CHARACTERISTICS

208/230/1/60, 208/230/3/60, 460/3/60 208/230/1/60, 208/230/3/60, 460/3/60 208/230/1/60, 208/230/3/60, 460/3/60 550 208/230/1/60, 208/230/3/60. 460/3/60 208/230/1/60, 208/230/3/60, 460/3/60 208/230/1/60, 208/230/3/60, 460/3/60 208/230/1/60, 208/230/3/60, 460/3/60

208/230/1/60, 208/230/3/60, 460/3/60,

208/230/1/60, 208/230/3/60, 460/3/60 208/230/1/60, 208/230/3/60, 460/3/60 208/230/1/60, 208/230/3/60, 460/3/60 616 280 139/63 208/230/1/60, 208/230/3/60, 460/3/60 616

NOTE. Clearances must be maintained to prevent recirculation of air from condenser-fan discharge.

REQUIRED CLEARANCES TO COMBUSTIBLE MATERIAL - in. (mm) Maximum Extension of Overhang 48(1219.2)

Unit Top ........................... ■ .36(914.4)

Duct Side of Unit . .... 6 Min. (152.4 Min.)

Side Opposite Ducts .30 (762.0)

Bottom of Unit. .... .0

REQUIRED CLEARANCES FOR SERVICING - in. (mm)

Blower Access Panel Side ... . 30 (762.0)

Control Box Access Side . . 30 (762.0)

UNIT WT LB

530 536 243 119/54 148/67

556 574 580 263 130/59 586 265 131/59 161/73 586 604 610

A B

241 117/53 147/67

249 122/55 152/69 252

124/56 153/69

261 128/58

265

131/59

274

136/62 165/75

277

138/63 166/75

280

139/63

CORNER WT LB/KG

158/72 159/72

161/73

168/76 168/76

148/67 118/54 149/68 120/54 153/69 154/70 125/57 159/72

160/73 162/73 162/73 166/75 167/76 169/77 169/77

123/56

129/59 131/59 132/60 132/60 137/62 139/63 140/64

140/64

Fig. 3 — 48 Dimensional Drawing, Sizes NHT036 — NVT060

Table 1 — Physical Data

UNIT SIZE 48 NOMINAL CAPACITY (ton) OPERATING WEIGHT (lb) COMPRESSORS

Quantity REFRIGERANT* REFRIGERANT METERING DEVICE CONDENSER COIL

Rows

FIns/in. CONDENSER FAN

Nominal Airflow (Cfm)

Nominal Speed (Rpm)

Quantlty...Dlameter (in.)

Motor Hp (single-phase)

EVAPORATOR COIL

Rows

Fins/ln.

EVAPORATOR FAN

Nominal Cfm Nominal Speed (Rpm) Diameter x Width (in.) Motor Hp (single-phase)

FURNACE SECTION

Burner Orifice No. (Qty...drlll size) Burner Orifice No. (Qty...drlll size)

Pilot Orifice Diameter (in. ...drill size)

Pilot Orifice Diameter (In.)

RETURN-AIR FILTERS (sq ln.)t

Disposable Cleanable

•Operating charge is iisted on unit namepiate tRequired fieid-suppiied fliter areas are based on the iarger of the ARi-rated (Air Conditioning & Refrigeration institute) cooling airflow or the heating

airflow at a velocity of 300 ft/min for disposable type or 450 ft/min for high-capacity type Air filter pressure drop must not exceed 0.08 in wg

••Single-phase units

ttThree-phase units

(three-phase)

Natural Gas Propane Gas Natural Gas Propane Gas

NLT018 NLT024

IV2

450

1 20 20

600 800

2 44

2. 55 2 55

288 192

NHT024

454

10 X 8

2 44 3 44 2. 44 3 44

NLT030

460 470 476

2000

825

V10

'/3

3 55 2 55 3 55

NMT030 NHT030

2V2

Reciprocating Hermetic. 3500 Rpm

1000

528 352 416

AcouRater® Piston

niR 77

NLT036

480

R-22

1 20

1100

4 44 4 55 3 .55 4 55

NMT036

486

2500 1100

V4 1/4

1200

V2 V2

3 44 4 44 4 42 5.44

624 720

NET036 NHT036

490

10 X 10

490

4 54 5 55 6 55

530

Vio

3/4

480

2500** 3000tt

825** lioott

1200

NVT036

536

6 .44

Step 2 - Provide Unit Support

ROOF CURB — Install accessory roof curb in accordance with instructions shipped with curb. Install insulation, cant strips, roofing and flashing. Ductwork must be attached to curb.

IMPORTANT: The gasketing of the unit to the roof curb is critical for water integrity. Install gasketing material supplied with the roof curb. Improperly ap plied gasketing also can result in air leaks and poor unit performance.

Curb should be level to within */4 inch. This is necessary

for unit drain to function properly. Refer to Accessory Roof Curb Installation Instructions for additional information as required.

SLAB MOUNT — Place the unit on a solid, level concrete pad that is a minimum of 4-in. thick with 2-in. above grade. The slab should extend approximately 2-in. beyond the cas ing on all 4 sides of the unit. Install a gravel apron in front of condenser-air inlets to prevent obstruction of airflow by grass or shrubs. Do not secure the unit to the slab except when required by local codes.

Step 3 — Provide Clearances — The required min

imum operating and service clearances are shown in Fig. 2

and 3. Adequate combustion, ventilation and condenser air must be provided.

The condenser fan discharges through the top of the unit.

Be sure that the fan discharge does not recirculate to the condenser coil. Do not locate the unit in either a corner or under an overhead obstruction. The minimum clearance

under a partial overhang (such as a normal house overhang) is 48-in. above the unit top. The maximum horizontal ex tension of a partial overhang must not exceed 48 inches.

A CAUTION

Do not restrict condenser airflow. An air restriction at either the outdoor-air inlet (the entire surface of the out door coil) or the fan discharge can be detrimental to compressor life.

Do not place the unit where water, ice or snow from an overhang or roof will damage or flood the unit. Do not in stall the unit on carpeting, tile or other combustible mate

rials. The unit may be installed on wood flooring or on Class

A, B or C roof covering materials.

Step 4 — Rig and Place Unit — Use spreader bars

and crate top when rigging the unit. The units must be rigged for lifting as shown in Fig. 4. Refer to Fig. 4 for rigging weight and Table 1 for operating weight. Use extreme cau

tion to prevent damage when moving the unit. Unit must remain in an upright position during all rigging and mov ing operations. The unit must be level for proper conden

sate drainage; therefore, the ground-level pad or accessory roof-mounting curb must be level before setting the unit in place. When a field-fabricated support is used, be sure that the support is level and properly supports the unit.

A CAUTION

When installing the unit on a rooftop, be sure the roof will support the additional weight. Refer to Fig. 4 for corner weight information.

Table 1 — Physical Data (cent)

NLT

UNIT SIZE 48 NOMINAL CAPACITY (ton)

OPERATING WEIGHT (lb) 496 500 500 COMPRESSORS

Quantity______

REFRIGERANT* REFRIGERANT METERING

DEVICE

CONDENSER COIL

Rows FIns/ln.

CONDENSER FAN

Nominal Airflow (Cfm) Nominal Speed (Rpm) Quantlty...Dlameter (In.) Motor Hp (single-phase)

EVAPORATOR COIL

Rows Fins/ln.

EVAPORATOR FAN

Nominal Cfm Nominal Speed (Rpm) Diameter x Width (In.)

Motor Hp (single-phase)

FURNACE SECTION

Burner Orifice No. Burner Orifice No. Pilot Orifice Diameter Pilot Orifice Diameter (In.)

RETURN-AIR FILTERS (sq ln.)t

Disposable 720 Cleanable 480

•Operating charge is iisted on unit namepiate tRequired fieid-suppiied fiiter areas are based on the iarger of the ARi-rated (Air Conditioning & Refrigeration institute) cooling airflow or the heating airflow at a velocity of 300 ft/min

for disposable type or 450 ft/min for high-capacity type. Air filter pressure drop must not exceed 0 08 in wg

(three-phase)

_________

(three-phase)

(Qty...drlll size) Natural Gas (Qty...drill size) Propane Gas

(In. ...drill size) Natural Gas

Propane Gas

3 44 3 55

NMT

042

2500 3000 3500

V2 3/4 ’/2 3/4

4. 44 4 55 4 54 5 55

042

NET 042

3Vz

4 42 5 44

NHT

NVT

042

550

6 44

6. 55 3 .55 4 55 5 55 6 54 3 55

NLT

042

556 574 580

Reciprocating Hermetic, 3500 Rpm

3 44 4 44 5 44 6 42 3 44

NMT

048

R-22

AocuRater® Piston

018 77

NHT 048

048

586 586

009

816 544 640

NVT

048

NLT

060

604

NMT

4 44 5 44 4 55 5 55

060

610

2000

960

NHT

060

616

NVT 060

616

I 3450

6 42 6 54

Step 5 — Connect Condensate Drain

NOTE: When installing condensate drain connection be sure to comply with local codes and restrictions.

The unit disposes of condensate water through a %-in.

NPT drain fitting. See Fig. 2 and 3 for location.

Install a 2-in. trap at the drain fitting to ensure proper drainage. See Fig. 5. Make sure the outlet of the trap is at least one-in. lower than the unit drain pan connection to

Fig. 4 - Suggested Rigging

prevent the pan from overflowing. Prime the trap with

water.

If the installation requires draining the condensate water away from the unit, connect a drain tube using a minimum of %-in. OD copper tubing, y4-in. galvanized pipe or %-in. plastic pipe. Do not undersize the tube. Pitch the drain tube

downward at a slope of at least one inch in every 10 ft of

horizontal run. Be sure to check the drain tube for leaks.

UNIT 48 NLT018

NLT024 100 NHT024 NLT030 103 132 132 103 NMT030 105 133 133 105 NHT030 106 134 134 106 NLT036 NMT036 108 NET036 108 137 137 108 NHT036 117 147 148 118 NVT036 119 148 149 120 NLT042 109 139 139 109 NMT042 NET042 110 140 140 110 NHT042 117 NVT042 NLT048 128 NMT048 NHT048 NVT048

NLT060 NMT060 NHT060

NVT060

101

107

110 140

124

130 159 160 131 131 131

136 165 166 137 138 166 167

139 168 169

139 168 169 140

CORNER WT (LB)

B C D

126 126 99 127 129 129 101

136 136 137 137

147 147 117 153 158 159 129

161 161

127

140

154

162 162

100

107 108

110

125

132 132

139 140

r MIN

Condensate water can be drained directly onto the roof in rooftop installations (where permitted) or onto a gravel apron in ground-level installations. When using a gravel apron,

make sure it slopes away from the unit.

Step 6 — Install Venting — The vent cap assembly

is shipped in the burner compartment. Remove the access door to locate the assembly.

A CAUTION

The venting system is designed to ensure proper vent

ing. The vent cap assembly must be installed as indi

cated in this section of the unit Installation Instructions.

NOTE; Screw holes in the flue assembly and the unit flue panel are not symmetrically located. Make sure they are oriented properly when installing these components.

Refer to Fig. 6 and install the vent cap as follows:

1. Place vent cap assembly over flue panel. Orient screw holes in vent cap with holes in flue panel.

2. Secure vent cap in place by inserting the single screw on the right side of vent cap.

3. Place the vent cap guard over the vent cap. Orient holes in vent cap guard with holes in vent cap and flue panel.

4. Secure the entire assembly with the remaining 2 screws on the left side of vent cap and vent-cap guard assembly.

Step 7 — Install Gas Piping — The gas supply pipe

enters the unit through the access hole provided. The gas connection to the unit is made to the Vi-in. FPT gas inlet on the manual shutoff or gas valve.

Install a separate gas supply line that runs directly from

the meter to the heating section. Refer to Table 2 and the National Fuel Gas Code (NFGC) for gas pipe sizing. Do

not use cast-iron pipe. It is recommended that black iron

pipe is used. Check the local utility for recommendations concerning existing lines. Choose a supply pipe that is large

enough to keep the pressure loss as low as practical. Never

use pipe smaller than the ‘A-in. FPT gas inlet on the unit

gas valve.

For natural gas applications, the gas pressure at unit gas

connection must not be less than 5 in. wg or greater than

13 in. wg while the unit is operating. For propane applica tions, the gas pressure must not be less than 11 in. wg or greater than 13 in. wg at the unit connection.

When installing the gas supply line, observe local codes pertaining to gas pipe installations. Refer to the NFGC ANSI (American National Standards Institute) Z223.1-1988 NFPA (National Fire Protection Association) 54-1988 (in Canada, CAN/CGA [Canadian Gas Association] B 149.1, (2)-M86). In the absence of local building codes, adhere to the fol lowing pertinent recommendations:

1. Avoid low spots in long runs of pipe. Grade all pipe

V4 inch in every 15 ft to prevent traps. Grade all hori

zontal runs downward to risers. Use risers to connect to

heating section and to meter.

2. Protect all segments of piping system against physical

and thermal damage. Support all piping with appropri ate straps, hangers, etc. Use a minimum of one hanger every 6 ft. For pipe sizes larger than Уг in., follow rec ommendations of national codes.

3. Apply joint compound (pipe dope) sparingly and only to male threads of joint when making pipe connections. Use only pipe dope that is resistant to action of liquefied petroleum gases as specified by local and/or national codes.

Never use Teflon tape.

4. Install sediment trap in riser leading to heating section. This drip leg functions as a trap for dirt and condensate. Install trap where condensate cannot freeze. Install this

sediment trap by connecting a piping tee to riser leading to heating section, so that straight-through section of tee is vertical. See Fig. 7. Then, connect capped nipple into

lower end of tee. Extend capped nipple below level of

gas controls.

Table 2 — Maximum Gas Glow Capacity*

NOMINAL

IRON PIPE,

SIZE

(in.)

1 1.049

VA 1.380 VA

‘Capacity of pipe in cu ft of gas per hr for gas pressure of 0 5 psig or less. Pressure drop of 0.5 in. wg

(based on a 0.60 specific gravity gas) Refer to Table C-4, NFPA 54-1984

fThls length includes an ordinary number of fittings

INTERNAL

DIAMETER

(In.)

.622 175 120 .824 360 250

1.610

10 20 30 40 50

680 1400 950 2100

465 375 320 285 260 240

1460

200

770 600 580

1180 990

82 73

170

151

900 810

LENGTH OF PIPE, FTf

60 70 80

61 57 53 50

125 118

138

530 490 460 430

220

750 690 650 620

90 100 125 150

110 103 93 205 195 175

400 360 325

160 145

550 500

175

—

40 84 77

300 460

200

—

72 135 280 430

testing of the piping systems when test pressure in excess of 0.5 psig. Pressure test the gas supply piping system at pressures equal to or less than 0.5 psig. The unit heating section must be isolated from the gas piping system by clos ing the external main manual shutoff valve and slightly open ing the ground-joint union.

A CAUTION

Unstable operation may occur when the gas valve and manifold assembly are forced out of position while con necting improperly-routed rigid gas piping to the gas valve. Use a backup wrench when making connection to avoid strain on, or distortion of, the gas control piping.

A CAUTION

If a flexible conductor is required or allowed by the au thority having jurisdiction, black iron pipe shall be in stalled at the gas valve and shall extend a minimum of 2 in. outside the unit casing.

A WARNING

Never use a match or other open flame when checking for gas leaks. Never purge gas line into combustion chamber. Failure to follow this warning could result in an explosion causing personal injury or death.

Size Small Cabinet Large Cabinet NHT036-NVT060 25V2 in.

NLT018-NET042 20V2 in.

"A"

Fig. 8 — Location of Coii Area Not to be Drilled

5. Install an accessible, external, manual main shutoff valve in gas supply pipe within 6 ft of heating section.

6. Install ground-joint union close to heating section be tween unit manual shutoff and external manual main shut off valve.

7. Pressure-test all gas piping in accordance with local and national plumbing and gas codes before connecting pip ing to unit.

NOTE; Pressure test the gas supply system after the gas supply piping is connected to the gas valve. The supply piping must be disconnected from the gas valve during the

8. Check for gas leaks at the field-installed and factoryinstalled gas lines after all piping connections have been completed. Use soap-and-water solution (or method spec

ified by local codes and/or regulations).

Step 8 — Install Duct Connections — The unit

has duct flanges on the supply- and return-air openings on the side and bottom of the unit. See Fig. 2 and 3 for con nection sizes and locations.

NOTE: The design and installation of the duct system must be in accordance with the standards of the NFPA for instal lation of nonresidence-type air conditioning and ventilating systems, NFPA No. 90A orresidence-type, NFPA No. 90B; and/or local codes and residence-type, NFPA No. 90B; and/ or local codes and ordinances.

Adhere to the following criteria when selecting, sizing

and installing the duct system;

1. The unit is shipped in vertical configuration. To convert unit to horizontal application, remove side duct covers, save screws and install the covers on bottom duct openings.

2. Select and size ductwork, supply-air registers and returnair grilles according to ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers) recommendations.

A CAUTION

When drilling the duct-system fastening holes into the side of the unit instead of the unit duct flanges, use ex treme care to avoid puncturing the coil or coil tubes. See Fig. 8.

3. Use flexible transition between rigid ductwork and unit to prevent transmission of vibration. The transition may be screwed or bolted to duct flanges. Use suitable gas kets to ensure weather- and airtight seal.

4. Install external, field-supplied air filter(s) in return-air ductwork where it is easily accessible for service. Rec ommended filter sizes are shown in Table 1,

5. Size all ductwork for maximum required airflow (either heating or cooling) for unit being installed. Avoid abrupt duct size increases or decreases.

6. Adequately insulate and weatherproof all ductwork lo cated outdoors. Insulate ducts passing through uncondi tioned space, and use vapor barrier in accordance with latest issue of SMACNA (Sheet Metal and Air Condi tioning Contractors National Association) and ACCA (Air Conditioning Contractors of America) minimum instal lation standards for heating and air conditioning sys tems. Secure all ducts to building structure,

7. Flash, weatherproof and vibration-isolate all openings in building structure in accordance with local codes and good building practices.

Step 9 — Install Electrical Connections

A WARNING

The unit cabinet must have an uninterrupted, unbroken electrical ground to minimize the possibility of per

sonal injury if an electrical fault should occur. This ground may consist of an electrical wire connected to the unit ground lug in the control compartment, or conduit ap proved for electrical ground when installed in accor dance with NEC (National Electrical Code) ANSI/ NFPA (latest edition) (in Canada, Canadian Electrical

Code CSA C22.1) and local electrical codes. Do not

use gas piping as an electrical ground. Failure to ad

here to this warning could result in personal injury or

death.

A CAUTION

Failure to follow these precautions could result in dam

age to the unit being installed:

1. Make all electrical connections in accordance with NEC ANSI/NFPA (latest edition) and local electrical codes governing such wiring. In Canada, all electrical connec tions must be in accordance with CSA Standard C22.1 Canadian Electrical Code Part 1 and applicable local codes. Refer to unit wiring diagram.

2. Use only copper conductor for connections between field-

supplied electrical disconnect switch and unit. DO NOT

USE ALUMINUM WIRE.

3. Be sure that high-voltage power to unit is within oper ating voltage range indicated on unit rating plate. On 3phase units, ensure that phases are balanced within 2%. Consult local power company for correction of im proper voltage and/or phase balance.

4. Insulate low-voltage wires for highest voltage contained within conduit when low-voltage control wires are run in same conduit as high-voltage wires.

5. Do not damage internal components when drilling through any panel to mount electrical hardware, conduit, etc.

HIGH-VOLTAGE CONNECTIONS - The unit must have a separate electrical service with a field-supplied, water proof, fused disconnect switch mounted at, or within sight from, the unit. Refer to the unit rating plate for maximum fuse/circuit breaker size and minimum circuit amps (ampac ity) for wire sizing. See Table 3 for electrical data.

The field-supplied disconnect switch box may be mounted on the unit over the high-voltage inlet hole in the control corner panel. See Fig. 2 and 3.

Proceed as follows to complete the high-voltage connec tions to the unit;

1. Connect ground lead to chassis ground connection when using separate ground wire.

2. Run high-voltage leads into unit control box and con nect to contactor. See unit wiring label, and Fig. 9.

A CAUTION

TRANSFORMER CONTAINS AUTO RESET OVERCURRENT PROTECTOR.

IT MAY RESET WITHOUT WARNING STARTING HEATING OR COOLING SECTION OF THIS PRODUCT.

DISCONNECT POWER PRIOR TO SERVICING.

THIS COMPARTMENT MUST BE CLOSED EXCEPT WHEN SERVICING.

316056-201 REV A

Fig. 9 — Transformer Label

Table 3 — Electrical Data

UNIT

SIZE 01B

024

030

036

042

048

060

AWG FLA LRA MCA MOCP NEC RLA

NOTES: 1

In compliance with NEC requirements for multimotor and combination load and equipment (refer to NEC Articles 430 and 440), the overcurrent pro tective device for the unit shall be fuse or HACR breaker

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

_ y max voltage deviation from average voltage

NOMINAL

V-PH-HZ

208/230-1-60 208/230-1-60

208/230-1-60

208/230-3-60

460-3-60

208/230-1-60

208/230-3-60

460-3-60

208/230-1-60

208/230-3-60

460-3-60

208/230-1-60

208/230-3-60

460-3-60

American Wire Gage Full Load Amps Locked Rotor Amps Minimum Circuit Amps Maximum Overcurrent Protection National Electrical Code Rated Load Amps

Example: Supply voltage is 460-3-60

MODEL NO.

NLT018 187 253 82 49 0 NLT024

NHT024 NLT030

NMT030 NHT030

NLT036 NMT036 NET036 NHT036 NVT036

NLT042 NMT042 NET042 NHT042 NVT042

NLT048 NMT048 NHT048 NVT048

NLT048 NMT048 NHT048

NVT048

NLT060 NMT060 NHT060 NVT060

average voltage

AB = 452 volts BC = 464 volts AC = 455 volts

Average Voltage

VOLTAGE

RANGE

Min Max RLA

187 253

187 253 14.3

187

414

187

414 506 77 41 0 1 2

187 253 26 5

187 253 16.8

187

187 253 30 7

187

414 506 104 55 0 1 2

452 + 464 -r 455

1371

—JT— =457

11.6

253 21 1

14.7

253

506 7 1

23.9 95.4 1 5

253

15.3

253

21 4

COMPR

LRA

61 0

61.0

86.0 08

100 0 1 5

67.0

34 0

82 0

1140

84 0

42 0 1 2

135 0

130 0 22

CONDENSER-

FAN MOTOR

FLA

08 08

1 9

1.9

1.9 22 22

1.2

1.9 1 9 1 9

2.2

2.1

2 1

Determine maximum deviation from average voltage. (AB) 457 - 452 =5 volts (BC) 464 - 457 =7 volts (AC) 457 - 455 =2 volts

Maximum deviation is 7 volts.

Determine % voltage imbalance

% Voltage Imbalance =100 x

This amount of phase imbalance is satisfactory as it is below the maximum

allowable 2%

IMPORTANT: If the supply voltage phase imbalance is more than 2%,

contact your local electric utility company immediately

EVAPORATOR-

FAN MOTOR

FLA

2.5

2.5 12 17 1 25 25

3.0 30

3.0 45 45 45

30 30 45 45 45

1 5 1 5 23 23 23

3.0

45 45

4.5

3.0

4.5

4.5 1 5

1 5 23 23

2.3

4.5 45

4.5

62 45

4.5

62 23

2.3

62 6 46 7

6.2

32 12 17.4 25

AWG MIN

WIRE SIZE

"457

8 6

= 1.53%

POWER SUPPLY

MCA

13 6 20

21 2

21.2 21 7

30.9 30 9

32.4 32 4

32.4

23.3 23 3 24 8 25 1 25 1

11 6 11 6 124 124

12.4 34 3

34 3 35 9

35.9 35 9

24 0

24.0 25 5

25.8 25 8

123

12.3 13 1

13.1 13 1

39 7 39 7

39.7 41 4

27.7 27 7 27 7 29 4

13.8 138 138 147

35 5 50

MOCP

35 35 40 40 40

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