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Kato Engineering (Kato) offers a complete line of precision-engineered, highquality ac generators, motor-generator sets and controls for prime,

standby, and peak shaving power generation.

Kato generators supply power to tap the world’s resources; oil, gas, coal,copper, iron ore and lumber are all extracted from the earth with the help ofKato generators. Kato furnishes the power to keep the world moving. Ships,freighters, locomotives, aircraft and mass transit systems all use Katoequipment. Any place where dependable, controllable electrical power isneeded: hospitals, computer centers and telecommunication stations all rely onKato generators to supply clean power.

The ruggedly-constructed Kato generators survive the harshest environments,and the Kato name has become synonymous with dependable powergeneration worldwide.

Founded in 1926, KatoEngineering has a longtradition of design andmanufacturing excellenceand innovation:

• Kato was an early user of vacuum-pressureimpregnation for coilprotection.

• Kato was a pioneer in the use of split bearings on rotor shafts.

• Kato was an early user of permanent magnet and brushless excitation.

In 1995 Kato Engineering achievedcertification to ISO 9001, a qualityprogram that is recognized worldwide.

Prime, standby, conditioning

More Power to You!

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Superior design and manufacturing capabilityKato Engineering has a superiorstaff of professionals to supportresearch & development, design,manufacturing and service activities.And, as a subsidiary of Emerson,Kato has a broad network of humanresources, technical knowledge andmanufacturing capacity available toaugment our North Mankato, MNmanufacturing facility. All of theseassets allow us to use the latesttechnology to provide a reliableproduct with a competitive price.

From manufacturing existingdesigns to developing new, cutting-edge technology, from providingtechnical information before the saleto design, construction, startup andservice, we are ready to meet theworld’s critical power needs.

Finite element analysis is an integral part of Kato Engineering’s development and design programs.

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RotorsRotor poles are punched or fabricated from high-strength steel. The pole shapeis designed to withstand mechanical stresses caused by rotational forces andprime mover pulsations. The pole contour is optimized to generate lowharmonics in the voltage waveform.

Field coils are machine wound on the poles with high temperature insulatedcopper wires. The coil end and interpolar region are blocked to prevent coilmovement and distortion. Depending upon the application, damper bars areinserted into the pole face and brazed or welded at each end to complete thedamper/amortisseur winding. The purpose of the damper windings is toreduce the generator harmonics and absorb torque pulsations caused by theprime mover or an unbalanced load distribution. The damper windings alsoreduce system oscillations caused during parallel operation. The completerotor is either vacuum-pressure impregnated before the shaft is pressed or wetwound.

The shaft is precision machined from rolled or forged steel. The bearingsurfaces meet stringent tolerance requirements for runout and concentricity.The rotor is dynamically balanced to meet specifications.

Precision-designed andskillfully manufacturedstators and rotors areparamount to generatorperformance and life.

Rotors & Stators

From the laminations to theframes to the windings,stators are precisely designedand constructed for peakperformance and a long operating life.

For long and smooth operation,rotors are precisely made with thehighest quality components.

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StatorsFrames: Sophisticated designsoftware and over 75 years ofexperience ensure that the generatorframe is made with strength andsupport where needed instead of justadding useless size and weight. Statorframes are welded with heavy ringsand bar steel. The frame is reinforcedwith welding plates between bars orwith a heavy wrapper. Heavy gaugesteel is formed and fastened to theframe to provide an ample airflowpath. The endrings are preciselymachined to support the bearingbrackets.

Cores: Stator cores are built fromhigh-grade electrical steellaminations. Each lamination is coreplated on both sides to minimize coreloss and heating. Slots in the cores areskewed to minimize harmonicvoltages.

Random-wound windings: Randomwindings are used for selectedapplications under 1000 volts and forhigh-frequency generators. Thewindings are made with the highestquality round copper wire, which hasa heavy film coating rated at 200° C.

Form-wound windings: Insulatingtapes are precisely layered using stateof the art equipment to ensuremaximum insulation properties andoptimum fit in the coil slot,eliminating discharges that wouldshorten the generator’s operating life.In the stator, coil end windings arebraced and supported with surgeropes to withstand short-circuit faultconditions.

Vacuum-pressure impregnation:Entire stator assemblies are immersedinto liquid thermosetting epoxy resininsulation and vacuum-pressureimpregnated. The vacuum exhaustsair, moisture and other vapors fromthe windings and permits completepenetration of the epoxy resins, fillingvoids and creating a rigid mass withoptimum dielectric strength.

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Ball bearingThe most popular and universallyused bearing. Being permanentlylubricated or equipped with greasefittings, it is suitable for low, mediumor high speeds and single or two-bearing generators. The ball bearingis lowest in cost.

Spherical rollerbearingCapable of heavy thrust and radialloads, it has the additional feature ofbeing self aligning. It is suitable forboth single and two-bearingmachines.

Cylindrical rollerbearingExcellent for heavy radial loads andradial shock, such as railwaygenerators. The cylindrical bearing isalso suitable for low and mediumspeeds. It is used on two-bearingmachines only.

Split roller bearingUsed on large generators of low andmedium speed up to 1800 RPM. It isself aligning and can be replacedwithout moving the generatorsendbracket or shaft, a featuredesirable when the generator isdriven by an engine on each end.Because it is self aligning, this bearingis suitable for single or two-bearingmachines.

Sleeve bearingHas a long life and the ability to runat higher speeds and loads. It is alsocapable of high radial shock. Becauseit is split, it can be easily removedwithout disturbing the shaft andendbracket. It is self aligning and canbe used on single and two-bearinggenerators. It may be self lubricatedor pressure lubricated dependingupon the application.

Oil coolingWith pressure-lubricated systems, anexternal oil cooling system can beprovided to lower oil temperature.

Prime moverconnectionsSingle-bearing units may have eitherSAE flexible disk type couplings orforged flanged shafts for directconnection to engine flywheels.Generators with two bearings haveshaft extensions that are suitable fordirect coupling to prime movers.Close-coupled SAE housing adaptersare also available with both singleand two-bearing designs.

Bearings & Adaptation

Because bearings andadaptation are based uponvarious factors, includingload carrying capacity, speed and type of primemover, Kato Engineeringoffers several options.

Sleeve bearings can beeasily disassembled.

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Voltage regulationKato Engineering offers severalvoltage regulators for variousapplications. Our standard K65-12B(used for 65 Vdc field requirements)& K125-10B (used for 125 Vdc fieldrequirements) models areencapsulated for weather protection.Their solid state analog design is ULrecognized. They have the followingspecifications:

Sensing100 to 120 V +/-10% with standard10K ohm control, 1 phase or 3 phase,50/60 or 400 Hz; 1 VA maximumburden per terminal

Paralleling1 A or 5 A for 6% droop maximum; 10 VA maximum burden; isolated for use in either reactive droop orcross-current method

Regulation accuracy+/- 0.5% maximum over full range of generator loading and +/- 5%frequency variation

Under frequency protection breakpointsAdjustable 45 to 65 Hz (50/60 Hzregulators only)

Regulator responseLess than 4 milliseconds

Field excitationFast voltage response time togenerator load changes with shorttime constant is provided with theKato brushless excitation systems.This allows the voltage regulator toreact to changes in field excitationrequirements. Three-phase high-frequency revolving armatureexcitation current is full waverectified through six silicon typerectifiers mounted in heat sinks andpositioned in the air stream formaximum heat dissipation. Diode PIVrating is at least twice the peakoperating voltage normally required.

PMGA separate permanent magnetrotating exciter can be supplied inaddition to the brushless exciter as anoption. • Reduces the effects of both

conducted and radiatedelectromagnetic interference (EMI).With an EMI filter, the PMG and aKato voltage regulator will meet theemissions requirements of Mil-Std-461C, Part 9, Class C2

• Enhances manual voltage controlregulation as the PMG provides amore stable power source to themanual control

• Provides full exciter power,regardless of alternator voltage, formotor starting and is a separatevoltage source for use external tothe generator set, such as atachometer and relay options

• Provides an economical and simplemeans of reliable, responsive andstable input power to the voltageregulator

• Supplies continuous power to theexciter through the voltageregulator to maintain up to 300%short-circuit current from thealternator during a fault condition

Excitation & Regulation

Exciter with a PMG androtating rectifier

Kato’s solid state,encapsulated voltageregulator

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Standard featuresKato’s standard generators have thefollowing features:

• Open drip-proof and guardedenclosure that conforms to IP21, IP22 or IP23

• Kato three-phase voltage regulatorwith single turn voltage adjust

• Brushless exciter

• Drawings, including dimensional and electrical connection

• Operation and maintenancemanuals with replacement partslist, available as a hardcopy or invarious electronic formats

The Kato Design and Manufacturingteams also have the capability toprovide many other options to meetexact customer requirments:

• Stator temperature detectors (two per phase): embedded RTDs and thermocouples; surface-mounted thermistors

• Bearing RTDs

• Space heaters

• Lightning arrestors and surge capacitors

• Redundant diodes

• Rotor and stator monitoring

• Special enclosures and protection;IP55 outlet box, air filters

• Proximity probes

• Sound attenuation

• Permanent magnet exciter (PMG)

Features & Options

Generator with a standard IP22 enclosure

Certifications &standardsKato Engineering equipment ismanufactured in accordance withNEMA MG-1 and IEEE Std 115. Inaddition, we can comply with manyother certifications and standards:

CertificationsABSBASEEFA (ATEX)DNVBureau VeritasLloydsCSANKKUSCG 259VDEUL

StandardsNEMA MG-1IEEE 115ANSI C50.12BS 4999CSA C22.2NO.100Australian AS 1359IEC 34API-546ISO 9001Mil-Std-705

Optional features

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Testing

Standard testsGenerators are subjected to thefollowing standard commercial testsin accordance with IEEE Std 115,NEMA MG-1, or Mil-Std 705standards (Testing to IEC 60034,marine classification societies orother applicable specifications isavailable upon request):

• Resistance on all windings (cold)

• Insulation resistance on allwindings

• High potential on all windings

• Open-circuit saturation curve

• Voltage and current balance onwindings

• Phase sequence

• Mechanical balance (vibration)

• Circulating current (whenapplicable)

• Three-phase build-up short-circuit(conducted if the generator has aPMG or SBO)

• Voltage transient at rated kVA (voltage regulation, stability, and response)

• Regulator range (voltage adjust) test (if a regulator is provided)

• Tests on optional components (e.g., RTDs, space heaters)

Special testsIn addition to the standard tests, Kato can perform the following tests,which are usually done on the firstunit of a new design or on specialdesigns:

• Open-circuit saturation with slip rings

• Synchronous impedance curve(short-circuit saturation)

• Zero power factor saturation curve

• Summation of losses (efficiency tests)

• Reactances and time constants

• Overspeed

• Voltage waveform (harmonic analysis)

• Voltage modulation tests

• Temperature rise test

• Polarization index (stator)

• Water-immersion and spray tests

Witness testing and test reports arealso available.

Before manufacturing, Kato Engineering tests its designs usingsophisticated analysis software. During manufacturing wemonitor critical processes and test or inspect componentsbefore they move to the next step. Kato’s final test facilityincludes two seismic test bases and precise control and dataacquisition systems.

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Platform AC GeneratorsSimple but with advanced designs, Kato platform generators offer highreliability and easy access for maintenance. Used for a variety of applicationsand engine or turbine driven, they have the following specifications:

Power Rating: 500 - 3000 kW (low voltage), 500 kW - 15 MW (mediumvoltage), 750 kW - 15 MW (high voltage)

Voltage: up to 600 V (low voltage), 601 - 6000 V (medium voltage), 6001 -15,000 V (high voltage)

Power factor: 0.8 standard (other PFs available upon request)

Frequency: 60 Hz or 50 Hz, three phase (six-phase optional)

Speed @ 50/60 Hz: 1500/1800 RPM, 1000/1200 RPM, 750/900 RPM, 600/720 RPM

Efficiency: 88% to 97% based on power rating, operating speed and voltage.All Kato generators have a high grade of electrical steel to yield low core lossesand provide high efficiencies. Depending upon kW rating, premium steel maybe used, resulting in even higher efficiencies. Efficiency data for specificmodels will be furnished upon request.

Temperature rise: For continuous duty applications, generators are typically80° C, 105° C or 125° C rise by resistance per NEMA MG-1. Standby ratings areeither 105° C, 130° C or 150° C rise per NEMA MG-1. Rise is based on anambient temperature of 40° C.

Insulation: All windings are of Class F or Class H insulation using vacuum-pressure impregnation (VPI) cycle. Various types of epoxies are useddepending on the functional requirements of individual components.

Overload: Typical allowable overloads are 50% for 5 minutes and 10% for 2hours during 6 hours of operation. Short-circuit cabability is at least 15 secondsat 300%.

Kato Engineering’s platformac generator line includescustom-designed generatorsand modular generators forparticular applications.

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Voltage balance: With balancedloads, the voltage is held within 1.0%between phases.

Waveform: Generators are specificallydesigned to minimize harmonicdistortion. Typical waveformcharacteristics are as follows:

• Deviation factor is less than 5%

• Crest factor: 1.3 - 1.5

• Harmonic content: any singleharmonic is less than 3% and thetotal harmonic is less than 4%

• Telephone influence factor (TIF):meets or exceeds NEMA MG-1-22.43 standards

• Telephone harmonic factor (THF):meets or exceeds IEC 60034-1, B.9.2requirements

Please refer to the previous sections forstandard and optional features. Otheroptions are available upon request.

High-voltage generator for turbineapplication

Engine-driven low-voltagegenerator

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Packaged Generators

This new Kato Engineeringline is a group of commercialand industrial qualitygenerators that can meetthe broadest range ofstandby or prime powerrequirements. Competitivelypriced, they have theshortest build cycle time in the industry.

Ratings125° C/40° C ambient temperature rise, continuous duty, Class H

kW range Voltage RPM Hertz 210 to 2750 480 1800 60 150 to 2200 400 1500 50

1000 to 2750 4160 1800 60 800 to 2200 3300 1500 50

250 to 2100 480 1200 60 200 to 1775 400 1000 50

505 to 2100 4160 1200 60 400 to 1775 3300 1000 50

Standard featuresRandom-wound stators: multiple dips and bakes with Class H polyestervarnish and epoxy overcoat

Form-wound stators: vacuum-pressure impregnation with Class H polyester

Rotors: Class H epoxy brushed wet on each layer during winding

Enclosure: fully guarded per NEMA MG-1-25.4

Solid-state fully encapsulated voltage regulator and a permanent magnetgenerator

Cast iron end brackets and a fabricated steel frame

Bearings that are pre-lubricated, double shield, ball type, single row Conrad C3 fit with provisions for adding or changing grease. Minimum B-10 bearing life is40,000 hours for single bearing units.

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ConformityThe new line of Kato generatorsconforms to the applicable parts ofIEEE, NEMA, IEC and ISO standards.The generators have CSA listing andare suitable for submission as acomponent of UL 2200 certification.

Marine generators may be certified toAmerican Bureau of Shipping, LloydsRegister of Shipping, Bureau Veritas,DNV, RINA and others.

Quality StandardsThe new Kato line of generators ismanufactured in a plant that iscertified to the new quality standards,TS-16949, which includes ISO 9001.This was the first generatormanufacturing plant to achieve thiscertification.

Options• Digital voltage regulator with

VAR/PF control

• Reactive droop paralleling

• Cross-current compensationparalleling

• EMI filter

• Manual voltage control

• Stator or bearing temperaturedetectors

• Space heaters

• Class F stator epoxy

• IP22 or IP23 protection

Random-wound stators are standard on Kato’s packaged generator line on models below 600 V.

Packaged generator

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Traction Alternators

Built smaller and lighter,Kato’s traction alternatorshelp reduce vehicle payload.But rugged construction andsuperior insulation ensurethey can handle bumpy,grimy conditions as well as the thermal cycling causedby the constant accelerationand deceleration mine haul trucks and locomotivesmust endure.

For every application, Kato Engineering’s design objectives for tractionalternators are to be both mechanically and electrically compatible. Themechanical design ensures structural integrity, minimum vibration, maximumbearing life, a proper fit and accessibility for service. Electrically, the designmust ensure the required power is available for the specified loadrequirements.

Locomotive applicationsFor new or rebuilt 1500 to 3000 hp, 700 to 1250 Vdc and up to 4800 Idclocomotives used in switchyard and short road-haul applications.

A typical locomotive package consists of a traction alternator and a dualauxiliary alternator. The dual auxiliary alternator includes two components:

• A 188 kVA, 1.83 V/Hz 2400 or 1800 RPM companion for ac loads, such aselectric air compressor, radiator cooling fans and cab accessories

• An 18 kW ac rectified to dc 74-volt battery charger.

Different configurations of these locomotive packages are available dependingon the application.

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Off-highway truck applicationsFor ac drive mine trucks in the 260 to400-ton range.

Driven by Detroit Diesel 4000 series16V-4000 or 20V-4000 engines orCummins QSK60 and QSK78 seriesengines in the 2700 hp to 3600 hprange, they have the followingspecifications:

Vac: 1500 to 2000kVA: 1800 to 2700Frequency: 120 HzRPM: 1800 nominal

Kato Engineering has almost 30 yearsof experience in supplying tractionpower for mine-haul trucks. Thesetrucks are used in some of theharshest environments all over theglobe.

Off-highway trucktraction alternator

Locomotive traction alternator

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Motor-Generator Sets & High-Frequency Generators

Precision applications around the world, includinglaboratory testing, aircraftground support, lineconditioning on ships and shore power depend on the superiority of Katomotor-generator sets andhigh-frequency generators.

Motor-generator setsMotor-generator (MG) sets provide line conditioning and load isolation forcomputers and other sophisticated electrical systems. They can also performfrequency conversion. Long life, minimum maintenance costs, low harmonics,high overload capacities and many other features make motor-generator sets aclear choice over solid-state systems.

With input of 50 or 60 Hz, output frequencies of 50, 60, or 400 Hz are availableas standard. For custom designed systems, fixed frequency outputs from 25 Hzto 1200 Hz may be selected, or we can provide continuously variable frequencyusing a VFD on the motor. Power capacities range from 10 kVA to 20,000 kVAand up, depending upon system requirements.

Typically, Kato furnishes a factory-programmed PLC control panel to provide acomplete power conversion or isolation system. The panel is usually unit-mounted but can also be free-standing or wall-mounted. The panel will includethe motor starter, output circuit breaker, metering, protective relaying, avoltage regulator and any other required components. Manual and automaticparalleling are also available.

400-Hz generator foraircraft ground support

Motor-generatorset with aunit-mountedpanel

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High-frequencygeneratorsKato Engineering offers a completeline of high frequency (400 Hz)generators. These units provideeconomical power for groundedaircraft’s navigational equipment,ground power and military supportproducts.

Phase: 3Power factor: 0.8Voltage range: 115/200, 120/208,240/416, 277/480

Pole RPM kVA26 1846 up to 312.5 24 2000 up to 156 20 2400 up to 156(Other designs available upon request)

All units are available in a two-bearing design. Typically, units rated100 kW and lower with 26 or fewerpoles can be supplied in a single-bearing design for direct connectionto the SAE engine drivearrangements. Bearings are doubleshielded regreaseable ball type.

Rotor and stator insulation is Class For Class H with void-free resin.Efficiency is 82% to 94% dependingupon kW rating.

Paralleling panel for a threemotor-generator set system

When portability is a requirement, Katomotor-generator sets can be trailermounted.

Totally-enclosedmotor-generator set

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Special Cooling &Protection

In addition to our standardopen dripproof enclosure,used where there is anabundance of clean air, KatoEngineering offers a varietyof cooling and protectionoptions for gritty, moist orexplosive environments.

Totally enclosed air-to-air cooled (CACA/TEAAC)Air-heat exchanger cooled generators are available from 500 kW to 10 MW.CACA generators are typically used in dusty, salt-laden or corrosiveenvironments.

These units are equipped with one or two internal fans to direct the enclosedair up and through an array of stainless steel tubes, which are mounted on topof the generator. Air from a second external fan is directed through an outersheet metal enclosure to cool the tubes, and air is then exhausted on theopposite side of the generator.

Totally enclosed air-to-water cooled (CACW/TEWAC)Water-heat exchanger cooled units are available from 500 kW to 12 MW. Theseunits are commonly used aboard ship or on off-shore drilling rigs where thereis a confined space, harsh environment or flammable atmosphere and wherethere is an abundance of ocean water for cooling.

The units are equipped with one or two internal fans. Air is forced up andthrough a large air-to-water radiator within the generator enclosure. Air iscontinually re-circulated with the heat created from the generator beingdisplaced by cool water from the radiator coils. The radiator consists of aninner tube of 90-10 copper-nickel for corrosion resistance and an optional outertube to detect water leakage. A separate system to pump a continuous supplyof cooling water throughout the radiator must be supplied.

Totally enclosed air-to-air cooled unit (CACA/TEAAC)with shaft-mounted fan and flow diagram for asimilar unit with radiator-mounted fans

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Weather-protected IIFor generators that must be under anopen sky, Kato Engineering offersweather-protected II enclosures, builtto NEMA standards.

To prevent moisture entry, air intakesand exits have three 90° changes indirection. Air flow velocity is alsokept below 600 feet per minute. A“blow through” allows wind to pass through the unit.

Air filtersFor dusty, gritty applications, Kato Engineering offers air-filteredgenerators. Filters on these machinesremove over 78% of the particles withdiameters over 5 microns.

Air filters and mounting frames are made from stainless steel toprevent rusting and corrosion. Thefilters can be easily removed forcleaning with steam or soapy water.

A differential pressure safety switch is included. If the filter becomesclogged, the switch actuates. Theswitch can be connected to an alarm,indicator lights or shutdown circuitry.

Sealed windingsGenerators with sealed windings canwithstand water and salt spray. Theyare typically used outdoors in marineenvironments. They withstand waterimmersion testing per NEMA andAPI-546.

Totally enclosed air-to-water unit(CACW/TEWAC) and flow diagramfor a similar unit

Weather-protected II unit andair flow diagram

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Kato Engineering, Inc.P.O. Box 8447Mankato, MN 56002 USATelephone: 507-625-4011Fax: 507-345-2798Email: katoengineering@lsusa.comWeb: www.kato-eng.com Photo credits: Page 1: US Navy, Caterpillar,

NASA/JPL/Caltech, Ormat, Waukesha,Liebherr; Pages 10 &11: Waukesha; Page 13:Caterpillar; Page 15: Liebherr; Pages 16 & 17:US Navy.

Parts and ServiceWe at Kato Engineering know how important

your power needs are. That is why we haveexperienced factory field service personnel on call24 hours a day, every day of the year.

As well as repair and on site rebuilding, we canassist you with installation and startup andperform scheduled maintenance or training. We stock a variety of parts for quick delivery.

We provide technical manuals in electronic andhard-copy formats. These manuals includeoperation, maintenance and illustrated partsbreakdown.

Our knowledgeable and friendly staff is alwaysready to answer your questions, send a neededcomponent or arrange a site visit anywhere in the world.

Leroy Somer North America