1 / 5

How Auxiliary Contactors mounting may result into Mal-operation & hence tripping of Equipment

Case Study of Auxiliary Contactors mounting may result into Mal-operation & hence tripping of Equipment

systemprotection
Télécharger la présentation

How Auxiliary Contactors mounting may result into Mal-operation & hence tripping of Equipment

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ISO 9001:2015 ISO 45001:2015 (OH & S) Certified Company Case Study How Auxiliary Contactors mounting may result into Mal-operation & hence tripping of Equipment www.systemprotection.in +91-265-2225137

  2. Hello Friends / Sirs, Panelmanufacturermaysay, nothingis wrong, butasamaintenanceengineer, whatwehavenoticeisthatitmaybethe wrongwayinthelongerperiod. Why? ManyofyouhaveseenpositionofAuxiliary contactorinsideyourpanelasshownin BelowPic-1 & 2. Wearegoingtoexplainit. (Tryingitin simpleway) Butisittherightwayofputtingittogether? Pic-1 Pic-2 www.systemprotection.in +91-265-2225137

  3. Obviously, itisnotnecessarythatallthe contactorsareONatsametimeanditwill neverbe. Butyes2-3adjacentcontactors canbeONsimultaneously. Thiscase happenedinMay’2015. HODsir ofthatplantadvisedtocreate somespacebetweenalltheauxiliary contactorsinoneHTMotorpaneland comparethetemperaturewiththosewith nospaceinbetween. Thiswas HODsir past experiencesregardingPower & Auxiliary Contactors. Aboveauxiliarycontactorswereplacedin oneHTPanelwhichwasusedtostartaMill (Motor) inaprocessindustry. After3yearsof commissioningofplantoneHTpanelgot tripped. Andwhatengineerfound, thatcoil ofAuxiliarycontactorwasburntandhence itwasnotpickingupandthatfeedback signalwasnotgoingtocontrolroom, ultimatelyresultingintotrippingofthat MotorandhencethatsectionofthePlant. Andin3-4daysteamfoundtherootcause. ThetemperaturedifferenceonAux contactorsbetween2panelswasaround5- 6degrees. Actually, theminorheatwhich wasgeneratedwhencontactorwas ON, was notabletodissipateproperlyduetono spacebetweenAuxcontactors, anddueto thisheatgeneratedbythecontactorswere accumulatedthereonlyandinthelongrun contactorcoilwasburningorcontactor failing. Maintenanceteamreplaceditwithspare Auxcontactor, that’swhatnormallywedo asamaintenanceengineersothatthe breakdowntimedecreases. Theytryto foundoutwhatcouldhavehappened, but didn’tgetitinfirsttimeexcepttheAux contactorfailedwasheated. (*Note – therecouldbemanyotherreasons fortemperaturedifferenceinpanels) TheycheckedthesamewithOtherHT paneltooandyestemperatureon contactorsinPanelwithsomespaces betweenAuxcontactorswasonlowerside comparedtothosewithnospacebetween AuxContactor. Thesamewasimplemented acrossplant, asperthespaceavailable. Sameproblemoccurs2timesmorewithin 6-7monthsinotherPanelofHTmotorand againplantgottripped, reasonfoundtobe sameasabovecoilfailedandAuxcontactor foundheated, butthistimetheyhaveto findtherootcausestoo. Aftercheckingall thethingsfromlooseconnectionsto earthingtheydidn’tfindanythingwrongin wiringoranyotherabnormalities. Thentheydecidedtochecktemperatureall ofsuchmotor, transformerandfeeder panelswithtemperatureGun. Yes, therewe foundsomedifferences. TemperatureonAuxiliarycontactorwas highersidecomparedtootherpartsof controlcabinetinHTpanel. Andonfurther analysistheyfoundthattemperatureof4-5 contactorswhichwere ON wereonhigher side. Maintenanceteamweregettingcloser tofindtherootcause. www.systemprotection.in +91-265-2225137

  4. Pic-3 Pic-4 Also, everyplanthasitsownspaceproblemsinHTpanels, butwhatweasamaintenance engineerfoundoutthatkeepingasmallspacebetweenAuxcontactorisgoodinthelongrun. Youtoocantryinyourplant. Yes, wewouldliketohaveyourcommentsandsuggestionsonthismodification. www.systemprotection.in +91-265-2225137

  5. CONTACT INFORMATION 301/2/306, SilverlineComplex,OppositeBBC Tower,Sayajigunj,Vadodara - 390005, Gujarat, India. bdm@systemprotection.in www.systemprotection.in +91-265-2225137

More Related