Generator Maintenance

Excellence in Product Support Sup port

Gen er at o r Mai n t en an c e

Speaker: Aar A aro o n K emp em p f 2011 TC Conference Lafayett e, IN IN Caterpillar Caterpillar Confidential: Yellow

Excellence in Product Support

Ag A g end en d a

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Overview

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Shipping Ma Maintenance

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Startup Maintenance

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Regu Regula lar, r, Peri Period odic ic and and Ann Annua uall Mai Maint nten enan ance ce

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Monitoring Re Recommendations

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Insu Insula lati tion on Test est Rec Recom omm menda endati tion ons s

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Beari earing ng Tempe empera ratu ture re Guid Guidel elin ines es

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Bearing Replacement

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Stato tatorr Tempe empera ratu ture re Guid Guidel elin ine es

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Vibr Vibrat atio ion n Measu easuri ring ng Gui Guideli deline nes s

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Important Updates

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Maintenance Lit Literature

Caterpillar Caterpillar Confidential: Yellow


Overview •

Scheduled Maintenance – Who: • Customers and Dealers! • CAT Warranty Statement states that the User is responsible for performance of the requir ed maintenance. – What: Ap plications • All Applications (Standby, Prime, Continuous, etc.) – Where: • Onsite, before/during/after Storage, before/after Shipping – When: Product Life • Shipping, Storage, Start-up, Regularly, Periodically, Annually – How: Procedures • Cleaning, Drying, Storage, Insulation Resistance, Alignment, Vibration, Bearing Greasing, Bearing Temperature Monitoring, Stator Temperature Monitoring, Controls and Protection Settings – Why: Publ ications (OMMs and SOTAs for SR4,SR4B, and SR5) • SENR5359, SEBU6918, SEBU7270, SENR7968, KENR5284

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Caterpillar Confidential: Yellow


Generator Maintenance - Shipping • What happens when shipping maintenance is not effective?…

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Generator Maintenance - Shipping • Packaging – Proper generator set cover pro tection n eeds to be in pl ace for t he environment generator set is being ship ped in. • Handling – Proper lift ing of generator sets usi ng lif ting eyes and fix tures. – Refer to respectiv e OMM for mor e inform ation . • Shippi ng damages can’t b e claimed as warranty . – These damages sh ould be claimed th rough the shippi ng/freight com pany.

Example of generator foot damage from ship ping

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Example of g rease deterioratio n after improper shipp ing and storage



Generator Maintenance - Storage Below are some photos of adequate and inadequate stor age practices. In these examples, the generators/sets shou ld be properly covered fro m the elements when stored. REFERENCE: SEHS9031 “ Storage Procedure for Caterpillar Products”

BAD BETTER

BAD

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BEST

Tight w rapping is good for shipping and short stor age tim es. If longer stor age is requir ed, make sur e to cov er the package loosely.



Generator Maintenance - Storage •

Dry Location – Cover fo r pr otection – Loo se to allow g enerator to br eathe

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Turn ro tor ten (10) revolut ions every s ixty (60) days

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Maintain win din g temperature – At l east 5 °C h ig her th an the ambi ent t emp eratur e – Space heater

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Insulation test – (reference SEHS9124) – Insulation test mus t be done when generator is

Make sure to c ompl ete when package is no t in stalled and there is no in tention of installing i n the near futu re.

Make every effor t to co mplete when package is i n st orage and make sure to complete when package is being in stalled or is installed and not running (i.e., standby).

received – Insulation test mus t be repeated prior to start-up.

Example taken fro m SEBD0660 showing condensation inside the generator. Example of hot spot created on bearing race after long s torage period without r otor turning.

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Generator Maintenance - Start-up •

Before apply ing b attery and shore power vol tage to the Generator Set – Inspect g enerator for debris, foreign objects, leaks and loose connectio ns, broken fitting s, rubbing or d amaged wiri ng, guards and com ponents. Repair as necessary. • i.e., Lead ch affin g fr om generator st ator to bus. – Check for p roper ground ing. • (Reference REHS4634) – Check space heaters for pro per operation .

Example of lo ose PMG bolts, not n oted before startup

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Generator Maintenance - Start-up • System c heck pri or to Generator Set o peration – –

Must DOCUMENT data on each for future r eference

– Alignment (LEBW4975, SEHS7654, SEHS7259, SEHS7073, REHS0177). – Air gap (main generator, exciter, & PMG) even ar ound circumferenc e – Insulation test – (Reference SEHS9124) – Measure Generator winding resistances (SENR5359 for SR4B, KENR5284 for SR5) • Main Stator /Roto r, Excit er Stator /Roto r, PM Stator /Rotor • Compensate readings for temperature and use micro-ohmmeter • Record for tr end plot ting! – Coordination of s ettings – Generator control and prot ective settings • Factor y default settings not appli cable to every application • Dealer and/or thir d party cons ultant is r esponsibl e for Coordi nation Study at each sit e – Circuit breaker – ECM, EMCP, and CDVR, Droop (KW and K VAR) – Differential Prot ection, Reverse KVAR Prot ection , etc.

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Generator Maintenance - Start-up • System c heck when Generator Set is runni ng – Must DOCUMENT data on each for fut ure reference – Record the following at No Load and Full Load • Bearing temperature (per r espective OMM) • Stator temperature (per respect ive OMM) • Air inlet temperature (and at areas where air recirculation could exist) – Confirm no air recirculation is oc curring – Refer to TMI generator inf orm ation and generator n ameplate • Vibration levels (Reference A&I Guide LEBW4972) • Voltage regulator & excit ation sy stem – Sensing voltage – Excitation v oltage and c urrent (refer t o TMI generator i nfor mation) » Determined by Load and Power Facto r

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Generator Maintenance - Start-up • After stopping the Generator Set – Inspect the generator and report malfu nctions. • Inspect for loose, broken, rubbing or damaged wir ing or components. • Make repairs or adjustments to the generator set as necessary. – Check that generator air i nlet fil ter is clean, if applicable. – Verify generator space heater is operating.

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Generator Maintenance - Regular • During Generator Set operation – Must DOCUMENT and TREND data on each for future reference – Monitor Phase current, Neutral current, Voltage, Frequency, Power Factor, Harmonic content, and Load variation – Monitor Room Temperatures – Monitor Bearing and Stator temperatures (when applicable) – Monitor for Alarm and Shutdown Indicators – Check that generator air inlet filter is clean, if applicable.

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Generator Maintenance - Periodic • After stopping the Gener ator Set for periodic maintenanc e – Periodic Maintenance tim e interval is based on Appli cation • Reference respective OMMs – Must DOCUMENT and TREND data on each f or future referenc e – Inspect g enerator for debris, foreign objects, leaks and l oose conn ectio ns, broken fitt ings, rubbi ng or d amaged wiring , guards and compon ents. Repair as necessary.

– Inspect Main Stator & Rot or, Exciter, and PMG – Clean as needed (Mois ture, Salt, Dirt, Grease, Oil) – Reference SEHS9124 for Generator Cleaning and Drying – Check space heaters for proper operation. – Check Air Gap (main generator , exciter, & PMG) – Insulation Test – (SEHS9124)

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Generator Maintenance - Annual • After Stopping The Gener ator Set – Must DOCUMENT and TREND data on each for future referenc e – Complete Periodi c Maintenance Proc edures – Alignment (LEBW4975, SEHS7654, SEHS7259, SEHS7073, REHS0177). – Measure Generator Winding r esistances (SENR5359 for SR4B, KENR5284 for SR5) • Main Stator /Roto r, Excit er Stator /Roto r, PM Stator /Rotor – Vibration Levels (LEBW4972) – Generator Bearings and Wear Sleeves • Grease Bearin g(s) as r equired – Refer t o REHS4892 for greasing requir ements – Avoid over-greasi ng/mixing greases and use correct grease • Check for good in tegrity of lip seal – Inspect and clean all main curr ent carry ing m echanical cont acts such as circ uit b reakers and tr ansfer swit ches

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Generator Maintenance - Monitoring Recommendations • Trending – Understand the monitored process – Normalized readings •

For all resistance readings, correct for temperature

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Refer to SEHS9124

– Record on chart – Focus on changes occurring over time – Scheduled repairs instead of unplanned downtime

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Generator Maintenance - Monitoring Recommendations Time to schedule downtime and repair of the generator.

Shown above is an example of regular insulation tr ending and the result of not acting ahead of time.

Source: Graph taken and formatted fro m “ Stitch in Time” (Megger, 2006)

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Generator Maintenance - Insulation Test Recommendations (References: OMM & SEHS9124) • When to Test • Safety • Testing Process • Prepare for the Test • Insulation Resistance Test – Perform the standard 30/60sec test at a minimum

• Polarization Index Test – Perform when unit i s in storage and/or moist environment.

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Generator Maintenance - Bearing Temperature Guidelines • Bearing Temperature Set-points – All Applications – Alarm 85 °C – Shutdown 95 °C • Exceptions exist in specific SR5 product using synthetic g rease. – For 1800/3000 frame, set-points are: • Alarm 95 °C • Shutdown 105 °C • Temperature is affected by ambient but m ax settings are not! • Generators shipped with Platinum 100 ohm RTDs – Packages can be ordered with bearing RTDs – RTDs are 2-wire • Track and investigate any change from historical trend

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Generator Maintenance - Bearing Replacement • Removi ng Hub and Bearings – W hen applicable, heat front dr ive hub evenly with two (2) ros ebud torc hes with propylene gas and puller or use destructive method (ie. cutting tool, etc.) to remove hub with care not to damage rotor sh aft. – H eat should be appli ed to the hub fo r approx imately 5-6 minu tes. – Do not attempt to heat hub with one (1) torch, and forci bly pull off shaft. – P uller and ram drive shou ld be capable of su pply ing at least 35 tons of fo rce. – R efer to respective SOTA manual for fur ther bearin g removal inst ructi ons us ing specified tools. • Installing Hub and Bearing s – Use an indu ction heater, etc. to heat the ball b earin gs to recommended temperature and mount t o the shaft. – When applic able, evenly h eat the dri ve hub to specified temperature and moun t the hub to the shaft.

Reference respective generator SOTA manual for more bearing installation and removal information. Page 280



Generator Maintenance - Stator Temperature Guidelines

• Stator Temperature Set-Points – Alarm 180 °C, Shutdown 190 °C (Stan dby) – Alarm 155 °C, Shutdown 165 °C (Prime/Con tinuous) • Exception s exist fo r SR5 product – Alarm 200 °C, Shutdown 215 °C, (Stan dby) – Alarm 175 °C, Shutdown 200 °C, (Prime/Con tinuous) • Based on NEMA standards , it is recomm ended to stay below th e alarm setpoint s to prevent wind ing deterior ation. • Generators with Form Wound Stators ship ped with Platinum 100 ohm RTDs – Random Wound Packages can be ordered wit h stator RTDs – RTDs are 3-wire for com pensation accuracy • Track and Investig ate any Change from hist oric al trend • Output Lim ited by Rotor o r Stator Temp. • Temp. Rise Func tio n of Generator Output • Measurement Method – Embedded Detector – Rise by Resistance The standard, mus t add hot spot allowance • Refer to IEEE 112-1996 (Section 8.3.3)

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Generator Maintenance - Vibration Measuring Guidelines • Measure on package at normal operating temperature • Use monthly readings to establish baseline • Vibration levels are load dependent • Investigate significant changes – New frequencies showing up – Increasing amplitudes of origi nal frequencies • To accurately compare to factory guidelines per LEBW4972, vibr ation tool used must be factory approved. – Alternate tools can be used for site-specific trending purposes, but comparison t o factory guidelines cannot b e relied upon. – New factory to ol is curr ently being validated to replace the previously available CSI Vibration Analyzer Tool.

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Generator Maintenance – Important Updates •

SEHS9124 – Generator Cleanin g and Dry ing – Existing docum ent up dated to impr ove wordi ng and emphasize Polarization Index (PI) test for testing generators i n s torage and/or mo ist environm ents.

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REHS4892 – Generator Bearin g Servic e – Special Instruct ion p ublis hed in early 2010 to up date the latest bearing maintenance recommendations. – Single and Doubl e-shi elded bearings are recom mended for gr easin g at prescr ibed intervals. Research has sho wn gr ease does penetrate the shield when the bearin g bracket cavity i s 50% ful l.

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Bearing Change for 1800/3000 SR5 Generators – In late 2011, these generator s w ill be packaged wi th greaseable (2S-3230 grease) sing le-shielded bearing s i n pl ace of n on-greaseable synth etic grease doubl e-shielded bearing s. – This allow s the end-user to add new grease as the grease breaks down o ver time.

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Generator Maintenance - Literature • SEBD9205 Proper Storage of Generators • SEHS9031 Storage Procedures for Caterpillar Products • SEHS9124 Cleaning and Drying of Generators • LEXE0095 Electric Power Start-up Checklist • LEBW4975 Alignment A&I Guide • SEHS7654 Alignment - General Instructions • SEHS7259 Alignment of Single Bearing Generators • SEHS7073 Alignment of Two Bearing Generators • REHS0177 Alignment of Two Bearing Close-Coupled Generators • LEBW4972 Linear Vibration A&I Guide • SEBU7270 SR4/SR4B High Voltage OMM • SEBU6042 Maintenance for Standby Gensets

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Generator Maintenance – Literature, cont. • SEBU6918 SR4B Generator OMM • SENR7968 SR4 Generator SOTA Manual • KENR5284 SR5 Generator SOTA Manual • SENR5359 SR4B Generator Service Manual • SENR5833 Digital Voltage Regulator Service Manual • RENR2480 VR6 Service Manual • RENR7941 CDVR Service Manual • REHS4892 Generator Bearing Service • REHS4634 Grounding Design Guide for EPG Products

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Generator Maintenance

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