Centrifugal Chillers

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Product Manual PM STARTER-3

Group: Chiller

Date: October 2000

Supersedes: PM-STARTER-2

2000 McQuay International

Starters and Variable Frequency Drives

For Centrifugal Chillers


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2 PM Starter-3

Table of Contents

Introduction.............................................................................................. 3

Low Voltage Starters (200 through 600 volts)........................................... 4

General Specifications............................................................................................................4

Types ........................................................................................................................................4

Standard Components ............................................................................................................5

Options.....................................................................................................................................6

McQuay Starter Model Codes ..............................................................................................7

General Arrangement..............................................................................................................8

Selection Procedure ................................................................................................................9

Specifications ........................................................................................................................11

Illustrations ............................................................................................................................11

Dimensions ............................................................................................................................13

Medium & High Voltage Starters (2300 to 6900 Volts)........................... 16

Starter Types ..........................................................................................................................16

Standard Components ..........................................................................................................17

Options...................................................................................................................................18

McQuay Starter Model Codes ............................................................................................19

Selection Procedure ..............................................................................................................19

Specification ..........................................................................................................................19

Dimensions ............................................................................................................................20

Variable Frequency Drives....................................................................... 23

General....................................................................................................................................23

Standard Components ..........................................................................................................23Options...................................................................................................................................25

General Arrangement............................................................................................................25

VFD Dimensions ...................................................................................................................26

Power Factor Correction........................................................................ 27

Initial Issue October 1998

"McQuay "is registered trademarks of McQuay International1996 McQuay International

"Illustrations and data represent the McQuay International products at the time of publication and we reserve

the right to make changes in design and construction at anytime without notice"

Our facility is ISO Certified


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PM Starter-3 3

Introduction

McQuay offers a wide selection of conventional motor starting equipment as well as Variable Frequency

Drives (VFD) that are starters with the additional capability of regulating compressor motor speed.

Starters For low voltage (200 through 600 volts) there are wye-delta closed transition, autotransformer

and solid state starters. Medium voltage (2300 through 6900 volts) starters are across-the-line full voltage,

autotransformer reduced voltage, and primary reactor reduced voltage starters. Starters can be mounted

and wired on the unit for most chiller sizes or they can be free-standing with wiring between the chiller andstarter provided by the installer. A line-up of medium voltage starters can also be accommodated. A wide

range of options is available for individual job requirements.

Motor starters can be furnished by the customer provided they meet McQuay Starter Specifications and

are approved by McQuay.

Variable Frequency Drives While known and specified for their ability to control compressor motor speed

for efficiency enhancement, VFDs also perform starting and motor protection functions. They are

available for only 3/60/460-480 service.

VFDs are available only from McQuay and when purchased as part of the original chiller purchase.

Basic Electrical TermsLocked rotor amps (LRA): The amount of current that a specific motor will draw at start-up when full

voltage is applied across the line. LRA may be 6 to 8 times FLA or possibly higher in some cases.

Inrush current: The amount of current that a specific motor and starter combination will draw during start-

up. Normal inrush current will be substantially less than LRA for all starter types except for across-the-

line starters.

Full load amps (FLA): The maximum amps the motor is designed for.

Rated load amps (RLA): Actual amperage that the motor draws for a specific application. Centrifugal

compressor motors operate at a RLA significantly below their maximum full load amps. RLA is used to

determine electrical component sizing.

Starting torque: Minimum torque required to begin the motors rotation.

Interrupting capacity: The maximum fault current that a circuit breaker or fused disconnect can

successfully interrupt. As the rating increases, the construction becomes heavier duty. For disconnect

switches with fuses, the rating is based on 0 to 600 volts. For circuit breakers, the voltage and amperage

relationship is considered with interrupting capacity decreasing as voltage increases.

Withstand rating: There is a period of time that the short circuit current passes to the shorted circuit

before the protection device can open. This time can be as long as 0.020 seconds (one cycle). The

withstand rating of a starter is the maximum short circuit current that it can pass safely without emitting

sparks or debris.

Bypass contactor: Contactors that bypass auto-transformers, reactors or SCRs and allow full power to

reach the motor.

Phase amps: The current draw inside the delta connection of a wye-delta motor winding, and is equal to

0.577 x RLA of the motor for a specific load.

Open transition: Reduced voltage starter characteristic when the motor is temporarily disconnected from

power at the time the starter changes from the starting mode to the final operating mode. A second smaller

inrush spike will occur. McQuay does not recommend use of this type of starter.

Closed transition: Reduced voltage starter characteristic when the motor is NOT temporarily disconnected

from the line during the transition from starting mode to operating mode. The electrical load is transferred

to resistors during the transition phase and a second inrush spike is suppressed.


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4 PM Starter-3

Low Voltage Starters (200 through 600 volts)

General Specifications

Agency Approvals

All controllers are continuous duty AC magnetic type constructed in accordance with National Electric

Manufacturers Associations (NEMA) Standard for Industrial Controls and Systems (ICS). The lowvoltage starters comply with the requirements of the Canadian Standard Association (CSA) and a CSA

label is offered as an option. Underwriters Laboratory (UL) certification for Standard 508 is included

and a UL label is provided with low voltage starters .. Starters can be modified to meet most federal,

state and local codes.

Contactor Duty

Contactors are capable of carrying the specified current on a continuous basis and also handle locked

rotor amps on a temporary basis without damage.

Storage and Operating Environment

Starters can be stored at temperatures from -40F to 140F (-40C to 60C). Operating range is from 32F

to 104F (0C to 40C) with a maximum relative humidity of 95%.

Enclosure and Cable Penetrations

Unless stated otherwise, the starter enclosures for low voltage starters are NEMA 1 with gaskets.

Standard construction for free standing starters allows main power to enter the top of the starter and

load side connections through the bottom, lower sides, or back near the floor.

As an option, the normal low voltage freestanding starter depth can be increased to 28" deep to allow

space for a bottom power inlet or a top side power connection. Medium and high voltage cabinets are

30 deep and allow various wiring configurations without extended depth. Cabinet dimensions can

also change to accommodate disconnect switches, power factor correction capacitors and other

devices.

Adequate separation of high and low voltage sections and proper mechanical and electrical interlocksare provided to meet all safety and operating codes.

Motors

Type

Semi-hermetic, squirrel cage induction, 3-phase, 50/60 Hertz, 2 pole, single speed. Speed,

3550 rpm at nominal shaft horsepower at 60 Hertz, 2960 rpm at 50 Hertz. Continuous duty at

minimum of 15 years with a maximum number of starts expected of 15,000 and a minimum

delay between starts of 20 minutes.

Leads

Low voltage; 600 volts and below, will have six leads and are suitable for use with wye-delta, across-the-

line, auto-transformer, or solid state starters.

TypesThree types of reduced inrush low voltage starters are offered; wye-delta closed transition,

autotransformer, and solid state starters. The objective of these starters is to reduce the starting inrush

current while allowing the motor to generate enough torque to start. Reduced voltage starters also

allow a soft start which means that the motor gradually accelerates to normal operating speed. The

centrifugal chiller capacity control starts the compressor unloaded to minimize current and torque

requirements.


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PM Starter-3 5

Wye-Delta Closed Transition

This starter (sometimes called star-delta) is the most popular type for centrifugal chiller applications.

It reduces inrush current by first connecting the three motor windings in a wye configuration to

reduce the maximum inrush current to 33.3% of locked rotor amps and producing 33.3% of normal

starting torque. After a brief delay, the electrical load is momentarily transferred to resistors while the

motor windings are changed to the delta configuration. The resistors minimize the second inrush

current when the delta configuration becomes active. Open transition starters (without the resistors) are

not recommended. These starters are excellent for centrifugal compressors because of the wye-deltas

low inrush current, low starting torque and low initial cost.

Autotransformer

This starter type uses a transformer per phase with 50%, 65%, and 80% taps. The taps determine the

initial voltage and resulting inrush amps that will reach the motor. For centrifugal compressors, the 65%

tap is used allowing 42% of normal inrush current and produces 42% of starting torque. The 50% tap

will usually not produce enough starting torque and the 80% tap allows unnecessary inrush (64% of

LRA). After a designated time period, a bypass contactor closes allowing normal current to flow to the

motor and bypasses the transformers.

Solid State Starters

Solid state starters are another excellent type of starter for centrifugal compressors. This starter usessolid state switching devices called SCRs (Silicon Controlled Rectifiers) that control the flow of current

to the motor during start up.

The SCRs control the amount of voltage that reaches the motor which in turn controls the motors

acceleration and current inrush. Eventually, full voltage is applied and a bypass contactor is energized.

The contactor bypasses the SCRs and allows full current to the motor. The compressor size and motor

characteristics determine Setpoints. Starting torque requirements necessitate approximately three times

the rated load amps of the compressor motor.

Solid state starters are generally used in applications where it is desirable to provide precise control of

motor starting characteristics. The inrush current may possibly, but not necessarily, be reduced below

wye-delta starters.

Standard ComponentsThe following components are standard on all types of low voltage starters:

Main Control Relays

Starters are equipped with redundant motor control relays with coils in parallel and contacts in series to

interlock the starter with the chiller. These two relays constitute the only means of energizing the motor

contractors. No other devices (manual or automatic) with the capability of energizing the starter can be

used. The starter is controlled by the unit microprocessor.

Motor Protection and Overloads

Starter includes devices to provide monitoring and protection functions. These controls include: Solid state overload (overcurrent) protection

Phase unbalance protection

Phase reversal and phase loss protection

Under and over voltage protection

Adjustable overload to closely match motor performance


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6 PM Starter-3

Three current transformers to measure motor current and a fourth current transformer for input to

the chiller microprocessor.

Control Voltage Transformer

The starter is provided with a 3KVA control transformer with both secondary and primary fuses to

supply control power to the chiller.

Surge CapacitorsIn wye-delta and autotransformer applications, surge capacitors are provided as standard in low

voltage starters or motor terminal box to protect the compressor motor from voltage spikes.

Surge capacitors are not used with solid state starters.

Terminals

Solderless mechanical connectors to handle wire sizes indicated by the NEC.

OptionsA variety of options are available for low voltage starters and are dependent on the

chiller mounting method. The options are listed below and their availability is shown in

Table 1.

Auxiliary Relay

Two normally open and two normally closed contacts.

Motor Metering Devices

Analog ammeters and voltmeters with 3-phase selector switches.

Deluxe Motor Metering System

The deluxe motor metering system is the IQDP-4130 which includes digital readouts of 3-phase

amps, 3-phase volts, watt-hours, watts, volt-amps, VAR-hours, power factor, and frequency, all in a

single device.

Lightning Arrestors

Ground Fault Protection Relay

Pilot Lights

NEMA Modifications

The standard enclosure is NEMA 1 with additional gasketing.

NEMA 3R -- Rain resistant construction

NEMA 4 -- Rain tight construction

NEMA 12 -- Dust tight construction

Notes:

1. The UL label, and CSA certification are available for NEMA 1 only.

2. If UL/CSA is required for NEMA 3R, 4, 12, contact factory.

3. Motor terminal mounted starters for WSC063, WSC079, WSC087, WDC063, WDC079 and

WDC087 are only available with NEMA 1 enclosures.


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PM Starter-3 7

Lug Size Options

A wide range of lug sizes for field power wire connections are available and are shown on the

starter certified drawings.

Extended Warranty On Parts Only, or Parts & labor

Main Disconnect (with Padlockable Handle)

Non-fused

Fused, 600 volt fuse clips only, fuses by others

Circuit breaker

Power Factor Correction Capacitors

The McQuay chiller selection program prints out the unit power factor and will also

calculate capacitor size for power factor correction.

Table 1, Starter Option Availability

OptionMotor Terminal Mount

063, 079, 087 OnlyFree Standing or

Unit Mount

Ammeter X XVoltmeter X X

IQ-DP-4130 X XLightning Arrestors X

Ground Fault Protection X XIndicating Lights X

4-Pole Auxiliary Relay X XPower Factor Correction

Capacitors X

NEMA 3R XNEMA 4 XNEMA 12 X

California Code X X

Non-Fused Disconnect X XFused Disconnect X

Circuit Breaker X XExtended Warranty X X

McQuay Starter Model CodesThe McQuay starter codes adapt the Cutler Hammer codes for order entry and drawing

identification as follows:

WSR 089 A 5A

Starter

Type:

Wye-Delta=089

Auto Trans=060

Solid State=031

Size

A=Free Standing

E=Motor Terminal Mount


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8 PM Starter-3

General ArrangementLow voltage starters can be supplied in several different mounting arrangements

depending on the chiller size and starter type. See Table 2 for availability.

Motor Terminal Mounted: The starter is mounted on the chiller unit with the back

of the starter against the motor terminal box and wired directly from the starter to

the motor. This arrangement is available only on WSC/WDC 063, 079, or 087 units.

See cover photograph.

Unit Mounted: The starter is factory mounted on the side of the chiller unit and

connected to the motor with conduit and cable. Available on models WSC/WDC

048/050.

Free standing: Floor mounted separate from the chiller unit and field wired to the

compressor motor. This is available on all units and is the only starter arrangement

available for WDC 100 and 126.

Brackets and cable: Starters for WSC 100 and 126 units may be shipped separately

from the chiller unit and furnished with mounting brackets and interconnecting

cables for field mounting and connection by others. This option must be clearly

specified when chillers are ordered since brackets are welded onto the evaporator

during its construction.

Table 2, Starter Mounting Arrangements

Size

Motor Terminal

Mount

(72 in. High)

NOTE (1)

Unit Mount

(72 in. High)

Free Standing

(90 in. High)

Brackets &

Cables

(90 in. High)

WSC/WDC 050 X X

WSC/WDC 063 X X

WSC/WDC 079 X X

WSC/WDC 087 X X

WSC 100, 126 X X

WDC 100, 126 X

NOTE: 888 amp maximum


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PM Starter-3 9

Selection ProcedureUse the following procedure to select the proper starter size:

Step 1. Refer to the McQuay MS-85 selection program to obtain the compressor RLA. Find the LRA-

Delta (LRAD), from the rating side of the MS85 program, by clicking on the "Order Data"

button in the upper right corner. The value can also be found in the Motor Data Table in the

centrifugal product manual.

Step 2. Determine the starter type required and check the mounting arrangement from Table 2.

Step 3. Select the starter size from Table 3 that is above the maximum rated load amps (RLA). If the

initial starter size has a maximum LRAD that is greater than the LRAD of the motor, the initial

selection is acceptable. If the motor LRAD is greater than the starter LRAD, use the next larger

starter. The starter must meet RLA andLRAD requirements.

Table 3, Starter Size Selections

Wye-Delta Starter Auto-Transformer StarterSolid State

Starter

SizeMax

RLA

240/

480V

LRAD

600V

LRAD

Main

Lug

Rating

Siz

e

Max.

RLA

240/

480V

LRAD

600V

LRADSize

Max.

RLA

3A 156 859 859 5kA 3A 90 496 496 13 1353D 207 1385 909 10kA 3D 120 496 496 18 180

4A 233 1880 1880 10kA 4A 135 1080 1080 24 240

4D 365 2728 2196 18ka 4D 211 1575 1268 30 304

5A 467 3637 3117 18kA 5A 270 2100 1800 36 360

5D 623 4018 3291 18kA 5D 361 2320 1900 42 420

6A 935 5785 4625 18kA 6A 540 4000 3240 65 650

6D 1212 7794 7274 18kA 6D 760 4560 4560 85 850

7A 1400 8660 8417 30kA 7A 810 5000 4860

Notes:1. The A designation represents a NEMA rated all-purpose starter that is applicable to any motor application. These

starters have a lower maximum RLA and LRA rating to be suitable for unknown applications. Some owners and designers

desire only NEMA rated starters.

2. The D designation represents a definite purpose starter (such as a centrifugal chiller motor) where the duty and

application is known. The D starters meet the National Electric Code but are not specifically covered by NEMAstandards. It is common for definite purpose starters to be used with centrifugal starters.

3. Main lug rating is main lugs only short circuit rating.

Step 4. Select the disconnect/breaker option (if required) from Table 6

Step 5. With the size and type known, find overall starter dimensions from the table below. Detailed

dimension drawings are in the Dimension Section beginning on page 13.

Table 4, Starter Dimensions

Type Height, in. Width, in. Depth, in.

Wye-Delta, Free-Standing, Size 3A to 6A 90 36 21

Solid State, Free-Standing, Size 13 to 85 90 36 21

Motor Terminal Mount 72 36 15

Low Voltage Disconnect and Circuit Breaker Options

Non-fused disconnect

A molded case switch without an automatic trip, includes a through-the-door handle which can be

used to break all power to the starter and chiller.

Fusible disconnect switch (less fuses)

A fused disconnect switch is identical to the non-fused disconnect except that a fuse block is added.

It is industry practice for the installer to supply the fuses. Fuses are NOT included. The interrupting

capacity for 200 to 600 volts is 100,000 amps. Refer to the chart below for fuse sizes.


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10 PM Starter-3

Table 5, Fuse Sizes

Fuse Class Fuse Range ( amps) RLA Range (amps) C enter line D im. H ol e to Ho le

(in)

Mounting Pattern

220 A, Class J 110A to 200A 81A to 160A 4.375 2 bolt

400A, Class J 225A to 400A 161A to 322A 5.25 2 bolt

600A, Class J 450A to 600A 323A to 480A 6.00 2 bolt

800A, Class L 601A to 899A 481A to 640A 6.25 2 bolt

1220A, Class L 1000A to 1200A 641A to 960A 6.25 (1), 9.375 (2) 4 bolt

2000A, Class L 1350A to 2000A 961A to 1289A 6.25 (1), 9.375 (2) 4 bolt

Notes:1. Inside hole to inside hole

2. Outside hole to outside hole

Thermal-magnetic Circuit Breakers

Thermal-magnetic circuit breakers are available with standard, high and ultra high interrupting

capacity.

Highest interrupting capacity circuit breakers, Tri-Pac

The Tri-Pac is a combination fuse and breaker unit that offers the highest interrupting capacity.

The interrupting capacity for 200 to 600 volts is 200,000 amps. Available only on free-standing

starters.

Table 6, Ratings and Interrupting Capacity (kA) for Circuit Breakers, Wye-Delta, Solid

State, and Autotransformer Starters

Non-Fusible

Disconnect

Fusible Disconnect

(Free-standing Only)Standard Interrupting Circuit Breaker

Interrupting

Capacity(kA)

Max

RLA Fram

eRating

Fram

eRating

Fuse

Clip

Fuse

Clas

s

Fram

eRating

240 V 480 V 600 V

156 K-SW 200 K-SW 200 200 J JD 250 65 25 18

296 K-SW 400 K-SW 400 400 J KD 400 65 35 25

444 K-SW 600 K-SW 600 600 J LD 600 65 35 25

606 K-SW 800 K-SW 800 800 L MDL 800 65 50 25

888 NDK 1200 NDK 1200 1200 L ND 1200 65 50 25

1185 RDK 1600 RDK 1600 2000 L RD 1600 125 65 50

1481 RDK 2000 RDK 2000 2000 L RD 2000 125 65 50

High Interrupting Circuit Breaker Ultra-High Interrupting Circui t Breaker

Interrupting Capacity (kA) Interrupting Capacity (kA)Max

RLAFram

eRating

240 V 480 V 600 VFrame Rating

240 V 480 V 600 V

156 HJD 250 100 65 25 JDC 250 200 100 35

296 HKD 400 100 65 35 KDC 400 200 100 50

444 HLD 600 100 65 35 LDC 600 200 100 50

606 HMDL 800 100 65 35 NDC 800 200 100 50

888 HND 1200 100 65 35 NDC 1200 200 100 50

1185 RD 1600 125 65 50 RDC 1600 200 100 65

1481 RD 2000 125 65 50 RDC 2000 200 100 65

Tri-Pac Circuit Breaker (Freestanding Only)

Max RLA Frame Rating 240 V 480 V 600 V

296 LA 400 200 200 200

606 NB 800 200 200 200

1185 PB 1600 200 200 200


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PM Starter-3 11

SpecificationsDetailed specifications for customers wishing to specify and purchase their own starters are contained

in McQuay Drawing (Specification) 359A999. Contact your local McQuay representative for a current

copy.

Illustrations

Figure 1, Wye-Delta Closed Transition Starter

SurgeCapacitor

Optional

Metering

MotorTerminals

Incoming

Power

I Q 500

Overload

Current

Transformer

Control

Transformer

Main

Contactors

Resistor

Contactor

Transition

Resistors

Motor Control

Relays (MCR)


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12 PM Starter-3

Figure 2, Solid State Starter w/ Disconnect

Incoming

Terminals

Motor

Terminal

Motor

Control

Signal

Silicon

Controlled

Rectifiers

(SCR)

Control

Transformer

Motor

Control

Relays

(MCR)


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PM Starter-3 13

Dimensions

Figure 3, Free-Standing, Wye-Delta, 36 Inch Wide

NOTES:

1. Enclosure height A = 90 in.

2. Enclosures are designed for incoming line cables at

top, outgoing load cables at bottom. Other wiring

practices may result in cable routing difficulties.

3. Use standard incoming lugs table for all

combination and non-combination units.

Note 1: Outgoing lug size applies to all Wye-Delta starters

Incoming LugsMain Lugs

Only

Outgoing Lugs(Note 1)

Max

RLANo. Size No. Size

156 1 #6-350 1 #6 - 2/0

207 1 #6-350 1 #6 - 4/0233 1 #6-350 1 #6 - 4/0365 2 #4-500 1 #6 - 300518 2 #4-500 1 #1/0 - 500623 3 #2-600 2 #1/0 - 500888 3 #2-600 2 #1/0 - 5001212 4 250-600 2 #2-600

Fused & Non-Fused Disconnect Switch

Terminals

MaxRLA

Type FuseType

Incoming Lugs

156 200A K-SW J (1) #6-250

296 400A K-SW J(1) 750 or

(2) 1/0-300

444 600A K-SW J (2) #2-600

606 800A K-SW L (4) 3/0-750

888 1200A NDK MCS L (4) 4/0-500

Series-C Circuit Breaker Standard, High, or Ultra-High Interrupting Capacity

Circuit Breaker Option Terminal InformationMax. RLA

Frame Incoming Lugs

156 J (1) #4-350

296 K (2) 2/0-250 or (1) 2/0-500

365 L (1) 4/0-600

444 L (2) 250-350

606 M (2) #1-500

623 M (3) 3/0-400

888 N (4) 4/0-500


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14 PM Starter-3

1. Enclosures are designed for incoming

line cables at top, outgoing load cables

at bottom. Other wiring practices may

result in cable routing difficulties.2. Use standard incoming lugs table for al

combination and non-combination

units.

Figure 4, Free Standing, Solid State, Sizes 13 - 85, 36 Inch Wide

NOTES:

Outgoing LugsSiz

e

Max

RLA No. Size

13 135 2 #4-500

18 180 2 2/0-300

24 240 2 2/0-300

30 304 2 2/0-300

36 360 2 4/0-500

42 420 2 4/0-500

65 650 4 4/0-500

85 850 4 4/0-500

99 1000 4 4/0-500


Terminals

Max

RLAType

Fuse

Type

Incoming

Lugs

156 200A K-SW J (1) #6-250

296 400A K-SW J(1) 750 or

(2) 1/0-300

444 600A K-SW J (2) #2-600

606 800A K-SW L (4) 3/0-750

888 1200A NDK MCS L (4) 4/0-500

Main Lugs OnlySeries-C Circuit Breaker: Standard, High, or Ultra-High Interrupting

Capacity

Circuit Breaker Option Terminal InformationMax RLA No. IncomingLugs Max. RLA Frame Incoming Lugs

156 1 350 156 J (1) #4-350

207 1 350 296 K (2) 2/0-250 or (1) 2/0-500

233 1 350 365 L (1) 4/0-600

365 2 500 444 L (2) 250-350

518 2 500 606 M (2) #1-500

623 3 600 623 M (3) 3/0-400

888 3 600 888 N (4) 4/0-500

1000 4 600 1000 R (4) 1-600


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PM Starter-3 15

Figure 5, Motor Terminal Mounted, WSC/WDC 063, 079, 087 and

Unit Mounted WSC/WDC 048-050

Notes:

1. Enclosures for top entry only.2. See chiller unit drawings for location of

the starter on the unit.

Incoming Lugs

Main Lugs Only

Outgoing Lugs

(Note 1)Max

RLANo. Size No. Size

156 1 #6-350 1 #6 - 2/0

207 1 #6-350 1 #6 - 4/0

233 1 #6-350 1 #6 - 4/0

365 2 #4-500 1 #6 - 300

518 2 #4-500 1 #1/0 - 500

623 3 #2-600 2 #1/0 - 500

888 3 #2-600 2 #1/0 - 500


Terminals

Max

FLAType

Fuse

Type

Incoming

Lugs

156 200A K-SW J (1) #6-250

296 400A K-SW J(1) 750 or

(2) 1/0-300

444 600A K-SW J (2) #2-600

606 800A K-SW L (4) 3/0-750

888 1200A NDK MCS L (4) 4/0-500

Series-C Circuit Breaker Standard, High, or Ultra-High Interrupting Capacity

Circuit Breaker Option Terminal InformationMax. RLA

Frame Incoming Lugs

156 J (1) #4-350

296 K (2) 2/0-250 or (1) 2/0-500

365 L (1) 4/0-600

444 L (2) 250-350

606 M (2) #1-500

623 M (3) 3/0-400

888 N (4) 4/0-500


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16 PM Starter-3

Medium & High Voltage Starters (2300 to 6900 Volts)

Agency Approvals

All controllers are continuous duty AC magnetic type constructed in accordance with National Electric

Manufacturers Associations (NEMA) Standard for Industrial Controls and Systems (ICS). Medium

voltage starters are rated as NEMA Class E2. Medium voltage starters have UL and CSA labels available

as an option. Starters can be modified to meet most federal, state and local codes.

Contactor Duty

Contactors are capable of carrying the specified current on a continuous basis and also handle locked

rotor amps on a temporary basis without damage.

Storage and Operating Environment

Starters can be stored at temperatures from -40F to 140F (-40C to 60C). Operating range is from 32F to

104F (0C to 40C) with a maximum relative humidity of 95%.

Enclosure and Cable Penetrations

Unless stated otherwise, the starter enclosures for medium and high voltage starters are NEMA 1 with

gaskets. Standard construction for free standing starters allows main power to enter the top of the starter

and load side connections through the bottom, lower sides, or back near the floor.

As an option, the normal low voltage freestanding starter depth can be increased to 28" deep to allow

space for a bottom power inlet or a top side power connection. Medium and high voltage cabinets are

30 deep and allow various wiring configurations without extended depth. Cabinet dimensions can also

change to accommodate disconnect switches, power factor correction capacitors and other devices.

Adequate separation of high and low voltage sections and proper mechanical and electrical interlocks are

provided to meet all safety and operating codes.

Motors

Semi-hermetic, squirrel cage induction, 3-phase, 50/60 Hertz, 2 pole, single speed, 3550 rpm at nominal

shaft horsepower at 60 Hertz, 2960 rpm at 50 Hertz. Continuous dutyat minimum of 15 years with a

maximum number of starts expected of 15,000 and a minimum delay between starts of 20 minutes.

Leads

Medium and high voltage; 2300 to 6900 volts, will have three leads and are suitable for across-the-line,

auto-transformer, and primary reactor starters.

Starter TypesMedium and high voltage starter types are across-the-line, reduced voltage autotransformer, and reduced

voltage primary reactor. They are designed as freestanding only.

Across-the-Line Starter

Across-the-line starters are very simple and consist of a primary contactor that allows locked rotor amps

to reach the motor when energized. These starters are low cost, provide the highest starting torque, and

can be used with any standard motor.

Autotransformer Starter

The autotransformer starter operation was discussed in the low voltage starter section. As with low

voltage starters, they are factory wired at the 65% tap for centrifugal compressors providing 42% starting

torque and 45% inrush current.

Once the starting sequence begins, the motor is not disconnected from the line that prevents a second

inrush spike from occurring. A bypass contactor is provided for across-the-line operation after the start


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PM Starter-3 17

up cycle is completed. Autotransformer starters are a good choice because of their efficiency and

flexibility.

Primary Reactor Starter

Primary reactor starters are a medium voltage starter that uses a reactor in series with the motor to

reduce inrush current. These starters have a higher inrush current for the same starting torque as an

autotransformer starter The starters are factory wired at the 65% tap which produces 42% starting

torque and 65% inrush current. A bypass contactor is provided for across-the-line operation after thestart up cycle is completed.

Standard Components

Across-the Line

Across-the-line starters contain the standard components listed below.

Reduced Voltage Primary Reactor

In addition to the standard components listed below, these starters also contain:

Drawout magnetic, three-pole, vacuum break shorting assembly

Three-phase starting reactor, factory set at the 65% tap

Reduced Voltage Auto-Transformer

In addition to the standard components listed below, these starters contain:

Drawout magnetic, three-pole, vacuum break shorting contactor

Drawout magnetic, two-pole, vacuum break starting contactor

Open delta starting auto-transformer factory set at 65%

Main Control Relays

Starters are equipped with redundant motor control relays with coils in parallel and contacts in series to

interlock the starter with the chiller. These two relays constitute the only means of energizing the motor

contractors. No other devices (manual or automatic) with the capability of energizing the starter can be

used. The starter is controlled by the unit microprocessor.

Motor Protection and Overloads

The starter includes overload protection functions. These controls include:

Solid state overload (overcurrent) protection

Phase unbalance protection

Phase reversal and phase loss protection.

Adjustable overload to closely match motor performance

Three current transformers to measure motor current and a fourth current transformer for input tothe chiller microprocessor.

Undervoltage (UV) Relay

The undervoltage relay is an adjustable three-phase protection system that is activated when the

voltage falls below a predetermined safe value and is factory set at 85% of nominal.

Control Voltage Transformer

The starter is provided with a 3KVA control transformer with both secondary and primary fuses to

supply control power to the chiller.


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18 PM Starter-3

Additional Standard Components

Mechanical type solderless connectors to handle wire sizes indicated by the NEC.

Three isolated vertical line contactors

Three-pole, gang operated non-load break isolating switch

Three vertically mounted current limiting power fuse blocks (fuses included)

Magnetic three-pole, vacuum break contactor

Single phase control circuit transformer Vertically mounted control circuit primary current limiting fuses

Current transformers

Load terminals

Control circuit terminal blocks and secondary fuses

Phase failure and reversal relay

Options

Motor Metering Devices

Analog ammeters and voltmeters with 3-phase selector switches..

Deluxe Motor Metering System

The deluxe motor metering system is the IQDP-4130 which includes digital readouts of 3-phase amps, 3-

phase volts, watt-hours, watts, volt-amps, VAR-hours, power factor, and frequency, all in a single

device.

Protection Devices

Overvoltage relay.

Lightning arrestors.

Ground Fault Protection

Surge Capacitors

Pilot Devices

Indicating lights, additional electrical interlocks and control relays.

NEMA Modifications

NEMA modifications for the NEMA 1-Gasketed standard enclosure include:

NEMA 3R -- Rain resistant construction

NEMA 12 -- Dust tight construction

Certifications and Approvals (Optional Adder)

UL certification for full voltage starters

UL certification for reduced voltage starters

CSA certification for full voltage starters

CSA certification for reduced voltage starters


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PM Starter-3 19

Power Factor Correction Capacitors

See the Power Factor Correction section at the rear of this manual for selection information.

McQuay Starter Model CodesThe McQuay starter codes adapt the Cutler Hammer codes for order entry and drawing

identification as follows:

WSR 202 M 04

Selection ProcedureSelect the correct size from Table 7 and options from the previous page.

Table 7, Starter Size Selection

Size 01 02 03 04 05 06 07

Max. RLA 18 27 32 46 55 65 88

Size 08 09 10 11 12 13

Max. RLA 107 125 148 172 204 255

Notes for medium voltage starters

Full voltage enclosures are 90" tall, 36" wide and 30" deep.

Reduced voltage enclosures are 90" tall, 72"wide and 30" deep.

Add 10" to height if main horizontal bus is required.

All starters are supplied with current limiting fuses and a non-load break isolation switch.

Load-break fused disconnect is available as an option. Consult factory.

IMPORTANT --- ISOLATION SWITCH Medium voltage starters are constructed to allow

components to slide out of the cabinet for servicing and repair. The non-load break isolation switch

disconnects the power to electrical components within the starter for safety of service personnel.

The standard enclosure is designed for the vacuum contactors to slide out. Contact the factory if

optional roll out construction is desired.

Medium voltage starters have a wide range of special options and application flexibility that is not

available with low voltage starters. Contact the factory for special needs.

SpecificationDetailed specification for customers wishing to specify and purchase their own starters are contained in

McQuay Drawing (Specification) 359A999. Contact your local McQuay representative for a current

copy.

Starter

Type:

Across-the-Line=202

Auto Trans=602

Primary Reactor=502

Size: 01 to 13

Voltage:

M=2300V to 4800V

H=5000V to 6900V


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20 PM Starter-3

Dimensions

Figure 6, Free Standing, Full Voltage (see notes on page 23)


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PM Starter-3 21

Figure 7, Free Standing, Reduced Voltage Auto-Transformer and Primary Reactor

(see notes on page 23)


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22 PM Starter-3

Detail Notes:

A - .75 diameter, typical of 4 holes. Mounting studs must extend a minimum of 2.50"

above grade.

B - HV conduit space, line and load for two high starters, upper starter cable should

enter in rear half of conduit space and lower starter should enter in front half of

conduit space (line connection w/o main bus).

B1 - HV conduit space (line w/o main bus).

B2 - HV conduit space (incoming line connection).

C - LV conduit space. For two high starters control wiring for upper starter should enter

in rear half of conduit space and lower starter control wiring should enter in front

half of conduit space.

D - Door dimensions to open doors 90 auxiliary compartment door. Not applicable for

two high starters.

E - HV conduit space, load.

F - HV conduit space, line only.

G - LV conduit space only.

H - For top entry load terminals located 32.50" from bottom of enclosure. For bottom

entry load term located 18.00" from bottom of enclosure.

H1 - For top entry load terminals located 76.00"from bottom of enclosure. For bottom

entry 61.00" from bottom of enclosure.

H2 - For top entry load terminals located 53.00" from bottom of enclosure. For bottom

entry load terminals located 40.50" from bottom of enclosure.

H3 - For top entry load terminals located 62.50" from bottom of enclosure. For bottom

entry load terminals located 48.00" from bottom of enclosure.

J - Load terminals located on left hand side of enclosure.

J1 - Load terminals located in reduced voltage enclosure on left hand side.

K - Maximum sill height 6.00" and maximum sill extension 3.00" for removal of contactor

w/o lifting device.

L - Line terminal for top cable entry.

M - Line terminal for bottom cable entry.

X - Steel bottom w/removable lead plates.

Y - Tolerances -0.0" + .25" per structure.

Z - Conduits to extend a maximum of 2" into structure.


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PM Starter-3 23

Variable Frequency Drives

GeneralWSC and WDC single and dual compressor chillers can be equipped with Variable Frequency Drive

(VFD). A VFD modulates the compressor speed in response to load and evaporator and condenser

pressures as sensed by the microprocessor. Despite the small power penalty attributed to the VFD,

the chiller can achieve outstanding part load efficiency. VFDs really prove their worth when thereis reduced load combined with low compressor lift (lower condenser water temperatures)

dominating the operating hours. The drives provide two important operating benefits.

The traditional method of controlling centrifugal compressor capacity is by inlet guide vanes.

Capacity can also be reduced by slowing down the compressor speed and reducing the impeller tip

speed providing sufficient tip speed is retained to meet the chiller's discharge pressure

requirements. This method is more efficient than guide vanes by themselves.

In actual practice a combination of the two techniques is used. The microprocessor slows the

compressor (to a fixed minimum of full load speed) as much as possible considering the need for

speed to make the required compressor lift. Guide vanes take over to make up the difference. This

methodology provides the optimum efficiency under any circumstances.

Standard Components1) Incoming and outgoing power terminals.

2) Transformer to supply power to the control circuit, oil heaters, and oil pump.

3) Redundant motor control relays with coils in series.

4) The VFD is current rated at 2 kHz carrier frequency for all 2001000 HP drives. The drive is

capable of running at 110% of nameplate current continuously and provides a minimum of 150%

of this rated current for 5 seconds.

5) The VFD will not generate damaging voltage pulses at the motor terminals when applied within

500 feet of each other. Both Drive and Motor comply with NEMA MG1 section 30.40.4.2 which

specifies these limits at a maximum peak voltage of 1600 Volts and a minimum rise time of .1

microseconds.

6) Units drawing 240 amps or less are air-cooled. All others are water-cooled. Factory mounted

water-cooled VFDs are factory piped to chilled water inlet and outlet nozzles. Free-standing

water-cooled units require chilled water supply and return piping for the VFD cooling. VFD has

a liquid-cooled heat sink assembly enabling liquid cooling of the drive through a single inlet

and outlet connection point, dissipating 25,000 BTUs/Hr for 600 HP, 16,000 BTUs/Hr for 350 HP

and 20,000 BTUs/Hr for 450 HP. The cooling circuit maintains water temperature between 60F

and 104F (15C to 40C).

7) The VFD and options are cUL 508 listed. The drive and options are designed to comply with

the applicable requirement of the latest standards of ANSI, NEMA, National Electric Code NEC,

NEPU-70, IEEE 519-1992, FCC Part 15 Subpart J, CE 96.

8) The VFD is functionally tested under motor load. During this load test the VFD is monitored forcorrect phase current, phase voltages, and motor speed. Correct Current Limit operation is

verified by simulating a motor overload. Verification of proper factory presets by scrolling

through all parameters is performed to ensure proper microprocessor settings. The computer

port also verifies that the proper factory settings are loaded correctly in the drive.


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24 PM Starter-3

9) The VFD has the following basic features:

a) An electronic overload circuit designed to protect an A-C motor operated by the VFD

output from extended overload operation on an inverse time basis. This Electronic

overload is UL and NEC recognized as adequate motor protection. No additional

hardware such as motor overload relays or motor thermostats are required.

b) An LED display that digitally indicates:

Frequency output

Voltage output

Current output

Motor RPM

Input kW

Elapsed Time

Time Stamped Fault Indication

DC Bus Volts

a) The capability of riding though power dips up to 10 seconds without a controller trip

depending on load and operating condition. In this extended ride through, the driveuses the energy generated by the rotating fan as a power source for all electronic

circuits.

b) RS232 Port and Windows based software for Configuration, Control, and Monitoring.

c) An isolated 0-20mA, 4-20mA or 0-4, 0-8, 0-10 volt analog speed input follower.

d) An isolated 0-10 V or 4-20 mA output signal proportional to speed or load.

e) Standard I/O Expansion Interface Card with the following features:

PI regulator for set point control

Four Isolated 24 VDC programmable digital inputs

An additional analog input for speed feedback to PI regulator

One Frequency Input (0 to 200 Hz) for digital control of current limit

Four programmable Isolated Digital Outputs (24 VDC rated)

One Form A output relay rated at 250 VAC or 24 VDC

Two NO/NC programmable output relays rated at 250 VAC or 24 VDC

1) The VFD includes the following protective circuits and features:

Motor current exceeds 200% of drive continuous current rating.

Output phase-to-phase short circuit condition.

Total ground fault under any operating condition.

High input line voltage.

Low input line voltage.

Loss of input or output phase.

External fault. (This protective circuit shall permit wiring of remote N.C. safety

contact to shut down the drive).

Metal Oxide Varistors for surge suppression are provided at the VFD input

terminals.


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PM Starter-3 25

VFD Model Sizes

VFD Model Max. Amps Power Cooling

VFD 019 170 3/60/460-480 Air

VFD 025 240 3/60/460-480 Air

VFD 047 414 3/60/460-480 Water

VFD 060 500 3/60/460-480 Water

VFD 072 643 3/60/460-480 Water

VFD 090 890 3/60/460-480 Water

VFD120 1157 3/60/460-480 Water

OptionsReactor

Used for control of line harmonics in some installations.

Incoming Line Termination (Chose one)

Terminal Block

Non-Fused Disconnect with through-the-door handle

Fused Disconnect with TD Fuses with through-the-door handle

Standard Interrupting Circuit Breaker with through-the-door handle

High Interrupting Circuit Breaker with through-the-door handle

Ultra High Circuit Breaker with through-the-door handle

Volts/Amps Meter with 3-phase Switch

Watt Transducer

General Arrangement

VFD Mounting

VFDs can be factory mounted on the same units and in the same location as conventional starters or

can be free-standing as shown below.

Chiller ModelMounted at Factory

(1)

Unit Mounted in Field Free-Standing

(2)

WSC, WDC 050 087 X X

WSC 100-126 X (3) X

WDC 100-126 X

Notes

1. Optional reactor is field mounted and wired to unit mounted VFD.

2. Optional reactor is factory mounted in the VFD enclosure.

3. Brackets and interconnecting cables shipped with unit


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26 PM Starter-3

VFD Line Harmonics

Despite their many benefits, care must be taken when applying VFDs due to the effect of line

harmonics on the electric system. VFDs cause distortion of the AC line because they are

nonlinear loads-that is, they don't draw sinusoidal current from the line. They draw their current

from only the peaks of the AC line, thereby flattening the top of the voltage waveform. Some

other nonlinear loads are electronic ballasts and uninterruptible power supplies.

Line harmonics and their associated distortion may be critical to AC drive users for threereasons:

1. Current harmonics can cause additional heating to transformers, conductors, and

switchgear.

2. Voltage harmonics upset the smooth voltage sinusoidal waveform.

3. High-frequency components of voltage distortion can interfere with signals transmitted on

the AC line for some control systems.

The harmonics of concern are the 5th, 7

th, 11

th, and 13

th. Even harmonics, harmonics divisible by

three, and high magnitude harmonics are usually not a problem.

Current Harmonics

An increase in reactive impedance in front of the VFD helps reduce the harmonic currents.Reactive impedance can be added in the following ways:

1. Mount the drive far from the source transformer.

2. Add line reactors

3. Use an isolation transformer.

Voltage Harmonics

Voltage distortion is caused by the flow of harmonic currents through a source impedance. A

reduction in source impedance to the point of common coupling (PCC) will result in a reduction

in voltage harmonnics. This may be done in the following ways:

1. Keep the PCC as far from the drives (close to the power source) as possible.

2. Increase the size (decrease the impedance) of the source tranformer.

3. Increase the capacity (decrease the impedance) of the busway or cables from the source to

the PCC.

4. Make sure that added reactance is "downstream" (closer to the VFD than the source) from

the PCC.

The IEEE 519-1991 Standard

The Institute of Electrical and Electronics Engineers (IEEE) has developed a

standard that defines acceptable limits of system current and voltage

distortion. A simple form is available from McQuay that allows McQuay to

determine compliance with IEEE 519-1991.

Line reactors, isolation transformers, or phase-shifting transformers may be

required on some installations.

VFD DimensionsDimensions for free-standing VFDs are available as Certified Drawings from the local McQuay

sales office.


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PM Starter-3 27

Power Factor Correction

Many local codes and utility companies require power factor correction to improve the utilization of

power.

Voltage and current in alternating current systems travel through wires in a sine wave pattern

developing positive charges and negative charges. The number of sine waves or cycles per second

is called frequency. The most common frequencies are 50 Hz and 60 Hz (cycles per second).Induction devices such as electric motors and solenoid coils use energy to create magnetic fields to

perform their tasks. This magnetizing energy does not perform usable work and will cause the

current to lag the voltage, traveling in a slightly different sine wave. When electrical measurements

are made, only the mean values for voltage and amperage are measured. These measurements do

not indicate that the voltage and amperage have slipped.

This slippage can be corrected by applying power factor capacitors. These capacitors have the

reverse effect causing voltage to lag current. When capacitors are used with motors, the two

devices offset each other allowing voltage and amperage to travel more consistently. It is good

practice to select capacitors that will correct to a maximum of 95% of total correction. Capacitors are

sized in terms of KVAR (1000 volt amp reactive). Readily available low voltage sizes are 2.5, 5.0, 7.5,

10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 75 and 100 KVAR. For medium voltage applications, available

sizes are 25, 50, 100, 150 and 200 KVAR. Contact the factory for larger sizes.

Power factor correction capacitors should be connected to the load side of contactors except for

solid state starters. If field supplied capacitors are used with solid state starters, they must be

installed upstream of the starter. At least ten feet of wire is required between the capacitors and the

starter. A separate isolation contactor must be supplied to disconnect the capacitors during starter

ramp-up and ramp-down. When the capacitors for solid state starters are supplied by McQuay, the

isolation contactor is furnished and ten feet of wire is coiled within the starter enclosure. Use two

sets of capacitors for WDC dual compressor units.

The McQuay chiller selection program prints out the unit power factor and will also calculate

capacitor size for power factor correction.


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Documents

Centrifugal Chillers