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r< ATTACHMENT 2 Instructions for Handling InerteenInsulating Fluid P.D.S. 54201 CM and Installation and Maintenance of Inerteen Transformers Westinghouse Electric Corporation SMALL POWER TRANSFORMER OlViSION, SOUTH BO STO N. VIRG IN IA SHARON TRANSFORMER OlViSION, SHARON. PENNSYLVANIA I B. 43-063-99E Ettccmc June. 1976 Supervenes 1 B 45-063-9*0. F e b r.jrx . 1976 " ^ I N P jC D :0026514 _ \ 753851 I\ CONTENTS Page PART ONE - INERTEEN INSULATING F L U ID ............................................... 3 Characteristics ................................................................................................................. Environmental Considerations........................................................................................ Handling .......................................................................................................................... Sampling and Inspection ................................................................................................ Testing Methods ............................................................................................................. Reconditioning ............................................................................................................... D is p o s a l............................................................................................................................ 3 3 -I 5 6 8 9 PART TWO - INSTALLATION AND MAINTENANCE OF INERTEENT R A N S F O R M E R S .......................................................... Installation ...................................................................................................................... Inspection ........................................................................................................................ Accessories and Fittings ................................................................................................ Finish .............................................................................................................................. Filling .............................................................................................................................. Filling Under Vacuum ........................................................................................ Placing in Service............................................................................................................. Pressure T esting....................................................................................................... High Altitude ................. 2 .................................................................................... Grounding Transformer Tank ............................................................................... Grounding Low VoltageWinding .......................................................................... Making Connections ....................................................................................................... Voltage Application .............................................................................................. Inspection ........................................................................................................................ 10 10 10 II 12 12 12 13 13* 13 13 13 14 14 ~ -- --NPC0002 651 5 753852 c( Part I - Inerteen Insulating Fluid Sec American National Standards Institute Guidelines C 107.1-1974 for complete information on handling and disposal of Askarels. Copies are available from: ANSI. 1430 Broadway. New York. N.Y.-10018 CHARACTERISTICS Inerteen is a highly pure, synthetic noninflammable and non-explosive insulating and cooling liquid. Chemically stable and nearly water white in color, Inerteen is not affected by reaction with other materials regularly used in the manufacture of Inerteen apparatus. It is non oxidizing and non-corrosive at temperature con siderably above those normally obtained in Iner teen apparatus. Inerteen will not sludge under any operating condition. Water is the main enemy of Inerteen and keeping it dry will insure long service life. The dielectric strength of Inerteen will com pare favorably with that of insulating oil when tested under the same conditions. Quality samples of Inerteen tested under laboratory conditions may show a dielectric strength in excess of 40KV. Care must be exercised in handling and testing Inerteen. Inerteen must be kept in clean, sealed containers to prevent loss by evaporation or contamination by moisture or dirt. Inerteen exerts a strong solvent action on most varnishes, gums, and paints. Such materials are not used in the construction of Inerteen apparatus. No materials should be used in Iner teen apparatus except those approved by the Westinghouse Electric Corporation. Inerteen has an irritating effect upon the skin. If il is necesiary to handle it. see the precautions under "Handling*. It should be remembered that mineral oil is completely miscible with Inerteen; in fact, it is impossible to separate mineral oil and Inerteen. 3. Color: (Maximum) 100 A.P.H. 4. Condition: Clear 5. Dielectric constant: At 1000 hertz 77F (25C). 5.7 to 5.9 At 1000 hertz 212F(100C). 4.8 to 5.0 6. Dielectric strength: (Minimum) 77F (25C) At point of shipment, 3SKV At point of receipt, 30KV 7. Electrical Resistivity: (Minimum) '500 x 10* ohms/cmJ (212F (I00C) at 500 volts DC) 8. Power factor At 60 hertz. 77F(25"C) 2% At 60 hertz. 2I2F ( )00*C) 25% 9. Fixed chlorine content: (Minimum) 42 perccnjt 10. Free chlorides: Less than 0.10 ppm 11. Neutralization number: Less than 0.014 mg of KOH cram 12. Pour Point: (Maximum) plus 7F (minus 14*C) 13. Refractive index: At 77 F (2 5 * 0 , 1.624 to 1.626 14. Specific gravity: At 6 0 ^ 6 0 ^ (15.5C/IS.5C). 1.381 to 1.392 15. Density : 11.5 pounds per gallon 16. Viscosity: At I00F (37.8C), 82-92 seconds 17. Moisture: (Maximum) 35 ppm SPECIFIC CHARACTERISTICS OF INERTEEN As outlined in "Method of Testing Askarels A.S.T.M. D901," the specific characteristics of Ineneen are: 1. Bum point: None 2. Chemical stability: No generation of free chlorides under normal operating conditions. ENVIRONMENTAL CONSIDERATIONS Inerteen is a sy nthetic Insulating fluid made.by the chturir.alion of a relatively common chemical, biphenyl. The chlorination is necessary to impart nonflammable properties to the Inerteen. The resulting polychlorinated biphenyls (PCB's) are relatively insoluble in water but soluble in fat, 753853 ~ HPC00026516 V 4 and extremely persistent in the environment. It has been shown by several laboratories that measurable amounts of the PCB's, particularly those with more than 50% chlorination, are present in our general environment and are a threat to certain species of wildlife. While Inerteen is generally regarded as being non-toxic to humans, very high standards of control in the overall program against pollution must be exer cised. Electrical apparatus (such as transformers and capacitors) using Inerteen are normally sealed to prevent escape of Inerteen into the environment. However, a carefully planned program of waste disposal must be followed at every step of the equipment life. This includes manufacture, repair and final disposition of the fluid and the Inerteen contaminated parts. To date the only acceptable destruction of the PCB's is by incineration at 2250C or higher under carefully controlled conditions. At this temperature Inerteen will breakdown into HC1. CO2 and water vapor. An alkaline scrubber is necessary to neutralize the HC1 and the final products released to the atmosphere are CO2 and steam. To be sure that the Inerteen and Inerteen contaminated materials do not contaminate the environment they must be incinerated in approved equipment. HANDLING short duration, it can be absorbed through the skin. Repeated contact over prolonged peri ods may result in severe dermatitis which may persist for many months after removal from exposure. Protective Equipment. When necessary, und er emergency conditions, to enter a space containing very high concentrations of Inerteen fumes or vapor, cither an approved gas mask or self-contained breathing equipment, should be worn. For lower, but still signifi cant concentrations, cartridge type chemical respirator should be worn. If the odor of Inerteen is noticed while wearing respiratory equipment, the wearer should go immediately into fresh air. Neoprene coated aprons and neoprene coated gloves may be used where necessary to protect the skin. Hand cream designed to protect against oils and petroleum solvents, (such as Ply 9 Gel made by Milbum Co. of Detroit) may be of some value where the use of gloves is not practical. When handling Inerteen. wash hands often with warm soapy water and in case of spillage onto clothing, remove the clothing as soon as - possible. The clothing must then be laundered prior to use. I. Sorely Precautions Breathing. The odor of Inerteen is noticeable at concentrations below the Mix'tmum Ac ceptable Concentration. Concentrations which exceed this may cause irritation of the eyes, nose, throat and upper respiratory tract. Much higher concentrations could cause in ternal reactions. Swallowing. Inerteen is highly toxic if taken internally. Swallowing of an ounce or two could cause severe irritation of the digestive tract and serious internal reactions. Skin Irritation. Although Inerteen is only a moderate skin irritant when contact is for 2. Storage Inerteen is shipped in tank cars, dm ms or cans. Inerteen in dmms or cans should be stored in a covered area and when stored out-of-doors the bungs should be down to prevent collection of water around the bung. A storage tank should be mounted on piers above the ground and accessible to all points for inspection for leakage. There should be a curb on the ground around the tank to UMitain any spillage or leakage. It is desirable, if possible, to keep Inerteen in storage at a temperature slightly above ambient to prevent moisture condensation. T\_ri*P C 00026517 \ 753854 Cl ) SAMPLING AND INSPECTION Sampling. Each container o f Inerteen must be sampled and tested prior to being added to a transformer and then should be added only if the dielectric strength is 30KV or above. It is desirable that periodic inspection of Inerteen apparatus be made and that samples of Incrteen be taken from each compartment and tested. Initially a sample should be taken after about 3 months o f operation and then, where operating conditions permit, at inter* vals of 6 months to 1 year. Accurate records should be maintained and if dielectric strength drops below 22KV it should be reconditioned. If facilities are not available for testing Incrtccn. see "Westinghouse Inertecn Testing Service*' below. Westinghouse Incrteen Testing Service. Many users of Inertecn do not have the necessary facilities for testing. In order that tho>e users may be able to make the periodic tests recommended. Westinghouse Electric Corp oration has established an Inertecn testing service to provide careful tests by experienced engineer, and provide a prompt report on the test results. Two special 16 oz. sample bottles per mailing con tain er Westinghouse Sj^24B1743b02. as well as necessary packing and printed matter, may be obtained by con tacting the nearest Westinghouse Office. (The bottle and the container will not be returned to the customer.) After drawing the sample o f Inertecn. the customer should seal the bottle and mail it to the WcstinehoiiM: Electric Corporation. Ma terials Engineering Laboratory, Sharon, lfa. 16146. To simplify these details, an instruc tion and order >hect and a printed return label have been included in the carton container. The instructions cover the taking of the sample and its proper preparation for mailing. The order sheet must be sent to the nearest Westinghouse office. In addition to dielectric tests. Westinghouse is also prepared to make a physical and chemical examination if so requested. (The customer should plainly indicate the type of service desired.) The physical and chemical examination consists of an examination o f the Inertecn by a competent chemist. Recommendations will be made as to the suitability of the Inerteen for continued use, whether it would be desirable and economical to clean it, and in a general way, the preferred method of clean ing. In submitting samples for this service, the history of the Inertecn represented should be given as completely as possible. (For details refer to the nearest Westinghouse Office). SAMPLING INERTEEN The dielectric strength of Inerteen is affected by the most minute traces of certain impurities, particularly water. It is important that the great est care be taken in obtaining the samples and in handling them to avoid contamination. There have been low dielectric test results reported from (he Held which, upon investigation, have been found to he largely a matter o f poor sampling. All sampling and testing equipment used Tor handling Inerteen and servicing Inerteen should be used for no other purpose. Care must be used in taking samples of Inerteen and sealing them prior to testing. It is desirable that samples o f Inertecn be removed from any container on clear da\ s only, and when the temperature of the Inerteen is at least as high as the temperature of the sur rounding air. Use only -tin containers with screwed metal caps or glass bottles with Inerteen resistant lids to hold Inerteen samples. If it becomes necessary to use other Hun factory sampling com aiders, they should be ringed with clean naptha, washed with detergent and water, and rinsed thorough)) in hot water, and then dried at approximately 110C for four hours with neck down in circulating air oven. If the containers are not used immediately after cleaning. thc> should be scaled tightly and stored in a dry, c'.mii pLce. An aluminum foil liner diould be put in the lid. 753855 e f t Provision is made on alt Inerteen transformers to obtain a top sample of the Inerteen, however on a transformer that is in operation, a sample may be taken from either the top or bottom since any moisture present wOI be mixed in, due to circulation of Inerteen. In sampling, allow at least one quart of Inerteen to run out to flush the sampling connection before collecting the sample. This flush material must be collected in a suitable container for disposition as per the section on Tiierteen Disposal" page 6. The Inerteen should be put into the sample containers immediately and the caps screwed on tightly. The label for each container should be marked clearly with the serial number of the transformer or compartment from which the Inerteen was taken. Before taking samples from a storage tank, the Inerteen should be allowed to settle for approximately twelve hours so that if there is any moisture present, it, having a lower specific gravity, will rise to the lop where the sample is to be taken. A clean sneak-thief should be used to obtain the samples. Essentially, the same precau tions to prevent moisture and dirt contamination should be used as outlined above. It is recommended that one 16 oz. bottle of Inerteen be taken as a sample for testing. At least one sample should be taken from a tank car of Inerteen. One sample may be taken from each drum, or if desired, a composite sample may be made from Inerteen from live drums, provided all of the drums are airtight. When the bung is first loosened, a hissing sound should be heard, which indicates that the drum has been airtight. When the composite type of testing is used and a sample is found to be unsatisfactory, a sample from each of the drums represented must be tested. When drums have been stored exposed to the weather, a sample from each drum must be tested to determine r it is suitable for use. DISPOSITION OF SAMPLE & CON TAINER. All samples must be collected in sealed, labelled containers for disposition as described in section on "Inerteen Disposal" page 9. All soltent rinses or test containers must be handled in a like manner. All containers, rags, and other solid materials involved in testing must be collected for proper disposition. TESTING METHODS Instruction for all tests listed correspond in general to the recommendations of the American Society for Testing Materials. 1. Dielectric Strength Test The testing transformer and the source of supply of energy shall not be less than 1/2 KVA, and the frequency shall not exceed 100 Hertz per second. Regulation shall be so controlled that the high tension testing voltage taken from the secondary or the testing transformer can be raided gradually without opening either primary or secondary circuit. The rate o r rise shall approximate 3000 volts per second. The voltage may be measured by an approved method which gives rooMneansquarc values. Some protection is desirable to prevent ex cessive flow of current when breakdown of the Inerteen takes place. This protection preferably should be in the primary or low ic'tage side of the testing transformer. It is not especially im portant for transformers of S KVA or less, as the current is limited by the impedance of the transformer. The standard test cup for holdir; the sample of Inerteen shall be made o f a ma:trial having a suitable dielectric strength. It must be insoluble in and unattacked by Inerteen or benzme and nonabsorbent as far as moisture, Inertcc.-.. or gasoline are concerned. The electrodes in the test cup between which the sample is tested shall be circular discs of polished brass or copper, I in. in d meter, with square- (90*) edges. The e l e c t s h a l l be mounted in the test cup with th.-r axes hori zontal and coincident, with a gap of 0.100 in. between their adjacent faces, and with tops of electrodes about 1-1/4 in. below tr. - top of Hie * if ~ ------- ^ ^ ^ 0 0 0 2 6 5 1 9 \ 753856 I( cup. (A suitable test cup is shown in Fig. 1. and portable testing outfits in Fig. 2.) a. Procedure Voltages shall be applied and increased uniformly at a rale of approximately 3000 volts (rms) per second until breakdown occurs as indicated by a continuous discharge across The spacing of electrodes shall be checked with a standard round gauge having a diam eter of 0.100 in., and the electrodes then locked in position. The electrodes and the test cup shaO be wiped dean with dry. calendered tissue paper or with a clean, dry chamois skin and thor- , oughty rinsed with Inerteen-free, dry benzine until they are entirely free from fibers. The test cup shall be filled with dry benzine, and voltage applied with uniform increase at the rate of approximately 3000 volts (rms) per second until breakdown oc curs. If the dielectric strength is not less than 25KV, the cup shall be considered in suitable condition for testing the Inertcen. If a lower test value is obtained the cup shall be cleaned with benzine and the lest repeated. The temperature of the test cup and of the Inerteen when tested shall be the same as that of the room, which should be between 68F and 86*F. C0*C and 30C) Testing at ; lower temperatures is likely to give variable results which may be misleading. Fig. /. FltiJ Ti?t Otpfur Dielectric Test The sample in the container shall be S ta te d with a swirling motion (to avoid introducing air) so as to mix the Inerteen thoroughly before filling the test cup. This is eten more important with used Inerteen than with new Inerteen as the impurities may be precipitated and the test may be misleading. The cup shall be filled with Inerteen to a height of no less than 0.79 in. (20 mm) above the (op of the electrodes. The Inerteen sh^ll be gently agitated by rocking the cup and allowing it to stand in the cup for three minutes before the first and one minute before each succeeding puncture. This u ill allow air bubbles lo escape. Fig. 1 /V-.vWe <VJ fruit:; Set. / 2 KVA. 35.000 V,>Jt$ 00026520 \ 753B57 c I i (he gap. (Occasional momentary discharges which do not result in a permanent arc may occur; these should be disregarded). b. Number of Tests I. Except as specified in (11) one breakdown test shad be made on each of five Fillings of the test cup. if the average deviation from the mean exceeds 10 percent or if any individual test deviates more than 25 percent from the average, additional tests shall be made. The dielec tric strength shall be determined by aver aging the first live tests that conform to the allowable variations. II. When Inerteen is tested in consider able quantity, so that the time required for testing is excessive and when it is merely desired to determine whether the breakdown safely exceeds the limit speci fied. or in those cases where the amount of Inerteen available for test may be very limited, one breakdow n test shall be made on each of two fillings of the test cup. If neither breakdown is below this value, the Inerteen may be considered satisfactory and no further tests shall be required. If either of the breakdowns is less than the specified value a breakdown shall be made on each of three additional fillings and test results analyzed in accordance with (I). c. Report The report shall include the volts (rms value) at each breakdown and the overage of the two or five breakdowns and the temperature of the Inerteen at the time o f the test. 2. Neutralization Test The Neutralization number is the number of milligrams of potassium hydroxide required to neutralize the acid in one gram o f Inerteen. Solutions Required a. Standard Potassium Hydroxide Solution (alcoholic. O.IN) - add 6 g. o f c.p.' solid KOII to 1 lifer of c.p. anhydrous isopropyl alcohol. Boil, add 2 g. of c.p. Ba (OH)2 and boil again. Cool filter and store in a chemically resistant bottle protected by a guard tube containing soda lime and soda asbestos (Ascarile). Stand ardize against pure potassium acid phthalate using phcnolphthalein as an indicator. b. Titration Solvent - Add 500 m l of c.p. benzene and 5 ml. of water to 495 ml. of c.p. anhydrous isopropyl alcohol Procedure. Into a 2S0 ml.Erlenmeyer flask intro duce 40 g. of Inerteen weighed accurately. Add 100 ml. of the titration solvent and 3 ml.of the indicator solution. Titrate immediately at a temperature below 30C. Consider the end point definite if the color change to green persists for 15 seconds. A blank shall be determined on the solvent. # Calculations. The neutralization number or mg. KOH per g. o f Inerteen * -- * S6j? A = m l KOH solution required for sample. B = m l KOH solution required for blank. N * normality of KOH solution. W = grams of sample used. RECONDITIONING Reconditioning will be necessary to remove water, foreign material and hydrogen chloride which may he present and contaminating Iner teen. The blotter filter .press, cartridge filter and the Inerteen conditioner will remove water and dirt which may he present. Various models of each of these types of apparatus are available. The Inerteen conditioner is the most effective for removing moisture, dirt, and other contaminating materials. It basically consists of a clay contziner. a clay filter, pump, attendant valves, gauges and fittings. Water cannot be effectively removed from either clay or litter material once they have become saturated with Inerteen therefore care *V *= ^,N P C 00026521 \ 753858 (( 9 should be taken to see that these materials are thoroughly dry prior to use. Any equipment used for conditioning Inerteen should first be thor oughly cleaned with benzine or naphtha to remove all traces of material foreign to Inerteen. If at all possible, separate equipment should be used for filtering Inerteen only. Hydrogen chloride, caused by arcing, may be eliminated by vigorously bubbling dry nitrogen through Inerteen. This should be done as quickly as possible following the failure to prevent the attack of HC1 on the cellulose insulation. The nitrogen should be passed in through the drain valve at the bottom and allowed to escape through a vent at the top. The nitrogen should be discharged through a pressure regulator attached to a stand pipe above the level of the Inerteen in the transformer to prevent the Inerteen from flowing into the regulator. The nitrogen shoutd be bubbled through the Inerteen at a rate of one to three cubic feet per minute for a period of 4 to 6 hours. This may require two to eight cylinders (220 cu. f t each) depending on the size of the apparatus. DISPOSAL Inerteen Liquid. Collect all scrap Inerteen liquid in a suitable metal container which can be satisfactorily sealed. Once the Inerteen is col lected it may be returned in sealed drums or tank cars to Monsanto .or other certified disposal companies as listed below. Ship prepaid to: otunlo Manna) Chamialj Com;jpi/ Nocan Corein* tOOfortl IMtargb Imlrvir* Oupotil Ottilien St loait. Ifircufi ( lif t ShafTuW. ttlrtxm 41361 CbraTial VdhrtionSenket, toe. 1550 Bita* toit Noca) Cj, Ra f o t 14107 Was Cefl. (ne. 405 Shoihoi Stritt Sul! M3, loi 564 Twin fat. Idaho 13301 tottiM Iniftftrwtit be. ro ia im lrd|fpsrt I J . 0X011 M . So 409 Dear Tim ' 77536 11351 SttmtH-'ffM/ latn laut*. U. 70107 A charge will be made for all returned Inerteen. Solvent-Rinses Contaminated with Inerteen. Sol vent rinses or other liquids contaminated with Inerteen should also be collected in scaled drums or tank cars and sent either to Monsanto or other certified disposal company. Solids Contaminated with Inerteen. All solids materials contaminated with Inerteen must be stored in impervious containers until disposal. This includes all glass, metals, papers, insulation, clay rags, filter cartridges, etc. These materials may be incinerated if suitable arrangements can be made for it to be done at a temperature sufficient to breakdown the Iner teen. Or they may be purged by cleaning with a proper fluid and the resultant fluid then may be incinerated using on approved procedure and temperature. The following disposition is recommended for various materials. Material Disposition Ab'Ofhinc die. filter paper, cartridns sawdiiM and rags Incinerate Coils Solvent clean or incinerate Cores Solvent clean Tanks A Tranes Solvent dean Copper or Aluminum Solvent clean Insula! un Incinerate Incineration. Incineration, whether o f liquids or contaminated solid materials, must be done at a temperature of at least 2250C and the stack must be equipped with "a suitable scrubber to remove 1ICI. Cleaning Contaminated Drums. The cleaning of drums which have contained used Inerteen re quires great core in order to insure a thoroughly clean drum. It is preferable to return such dnuns to the supplier where aJcquate cleaning facilities are available, rather than to attempt to clean them. If it is necessity to clean such dnims. :he follow ing procedure is recommended: Rinse the drum thoroughly with gasoline or petroleum distillate, using about one gallon each time, until the solvent shows no discolor ation after using. Allow it to drain, ihen pump out the last traces of solvent w in a vacuum pump, using a brass pipe flattened at r`^JJP C 00026522 I 753859 C 10 V. the lower end to exploit the comers of the drum. Collect all solvent rinse material for disposition as described above. dry air to remove any lingering explosive vapors. Screw the bung on tightly before removing the drum from the oven. Use a new washer with the bung to insure a tight seal. CAUTION: Do not use 8 steel pipe because of the danger of a spark igniting the gasoline or petroleum distillate vapor. Next, heat the drum with bunghole down in a ventilated oven at a temperature of at least 88C. (190F) for sixteen hours. (A simple oven for this purpose may be made from sheet metal and heated with steam or an electric heater.) Blow out the drum with diy nitrogen or CAUTION: Open flames must always be kept away from the oven to prevent igniting inflammable gases which might be remaining in drum when placed in the oven. The practice of refilling drums with lnerteen is undesirable and should be avoided whenever possible, for unless the utmost precautions are taken, the lnerteen is likely to become con taminated. Part II - Installation and Maintenance of lnerteen Transformers INSTALLATION For convenience in handling, all transformers are equipped with lugs or eyes for lifting and mov ing the complete assembly filled with lnerteen by use of a crane. Additional means are pro vided for the heavier parts such as covers, core and coils, radiators and terminal chambers. Jack ing lugs are also supplied on either the base or comers of the tank. A transformer should only be lifted or moved by jacks placed against these lugs and not against the cooling tubes, radiator valves, or other fittings. An indoor installation requires that the room in which the transformers are placed must be well ventilated so that the heated air can readily escape and be replaced by cooler air from the outside. If the room is poorly ventilated, this exchange of air takes place too slowly and the temperature of the air in the room may become excessively high. At any given load the tempera ture rise of a self-cooled transformer will be a fixed number o f degrees above the. temperature of the surrounding air. The temperature of the transformer is the sum of this rise and the air temperature: therefore, care must be taken to provide a room sufficiently ventilated to permit operation of transformers at a reasonable temp erature. Area of the air inlets should be such that the ambient temperature never exceeds 40C 1 104 Ft with an average over twenty-four hours not exceeding JOSC (86F): 50 lo oO square feet per IOCS) kva of transformer capacity has been satisfactory. Outlet openings with the same total area should be provided. Self-cooled transformers should always be well separated from one another and from ad jacent walls, partitions, etc., in order to permit free air circulation about the cases. This separa tion should not be less than 24 to 36 inches depend;." on ike sire o f the, units. INSPECTION AH lnerteen transformers are carefully inspected and tested at the factory and they are in good ^=^N PC 00026523 \ 753860 (( II condition when shipped; but it is desirable to inspect each transformer thoroughly before plac ing it in service. When a transformer is shipped complete and filled with Inerteen, this inspection should in clude a check of the Inerteen level, the tightening or adjustment of any parts that may have become loose or out of place, and determining the extent to which moisture may have entered the trans former. The latter can best be determined from the dielectric strength of the Inerteen. Inerteen used for filling transformers should have a dielec tric strength of 30KV or higher. When it tests less than this the Inerteen should be filtered. If the dielectric strength is very low or if there is any other evidence of moisture, it is necessary to dry the transformer. Inerteen transformers should be dried by the short circuit method with the transformer im mersed in the Inerteen and with the tank sealed tightly. During the drying out operation, the Inerteen should be circulated through a filter press or preferably through an Inerteen condi tioner. A filter press will remove dirt and most of the moisture, but the conditioner will remove these and other contaminating material* as well. The loading should be carefully watched and when the top Inerteen reaches a temperature of 60*C, the load should be reduced to obtain an approximately constant top Inerteen temperature based on the following table; SKortCircuit Amperes Maximum Temperature in Percent of Load of the Top Inerteen 50% 85C 75% 80 C 85% 75C While the windings of the transformer heat up, do not permit the temperature of the top Inerteen to exceed the value specified fora given percentage of load. This precaution is necessary because the windings will heat up more quickly and operate at a higher temperature than the Inerteen. If the windings are allowed to reach too high a temperature, the insulation will be dam aged. The drying of a transformer should be continued until the dielectric strength of samples of Inerteen taken from the transformer test at 30KV or hither. The desired load current should be obtained by short circuiting one winding and impressing the proper impedance voltage on the other binding. The full load impedance may usually be found on the instruction plate for the trans formers; if the impedance of the transformer is not known, it should be requested from the Westinghouse Electric Corporation, Sharon, Pennsyhania, by identifying the transformer with its serial number. If the transformer is at or lower tlun room temperature at the start of the drying process, circulation of 125 to 1505 of full load current will hasten the heating, and a higher top Inerteen temperature can be obtained more quickly by bbnketing the coolers uhen tubular coolers are used or by shutting off the radiator valves when radiators are used. The cover should be lagged to prevent condensation. The cover should be kept tightlv sealed during the temperature run, and until the transformer has cooled down to room temperature to prevent condensation. This also prevents the release of hot Inerteen vapors which are quite objection able. particularly if the ventilation is poor. CAUTION: It is not safe to attempt the drying out of transformers unless constant attention is given to the job. ACCESSORIES AND FITTINGS Bushings, fittings, and accessories when boxed ar.d shipped separately should be mounted as shown on the outline drawing. Proper installation ----- --------- ^ = r ^ N P C 0 0 0 2 6 5 2 4 753861 12 $ instructions when necessary are included in the instruction leaflets for component parts. Care must be exercised when these components are fitted to eliminate the accidental introduction of moisture in any form inside the transformer. Where blind flanges are removed before fittings art mounted, the level of the Inerteen must be lowered below the openings that will be made. FINISH Any portion of the paint film damaged during shipment or installation must be repaired as quickly as possible. To do this, clean the damaged portion by means of a scraper or sandpaper, wipe thoroughly with a solvent dampened cloth, apply Westinghouse primer paint and allow it to dry for at least 24 hours, then apply a coat o f Westinghouse finish paint FILLING When putting new apparatus into service, see that the apparatus tank is free from moisture and foreign material. t---------------------------------------- " IMPORTANT: Extreme precautions must be taken to insure the absolute dryness and cleanliness of the apparatus before filling it with Inerteen. and to prevent the entrance of water and dirt during the transfer of the Inerteen to the apparatuv The preparation and filling of outdoor appa ratus should preferably be done or. a clear, dry d j> : if this is not possible, protection against moisture must be provided. All vessels used for transferring the Inerteen should be carefully inspected to see hit they are absolutely dry and free from contamination. Use onI> un-metal ho<c or pipe when filling, since the lining of most other types of hose may be soluble in Inerteen and will contaminate it in a short time'. All joints should Ik* tight; where practical, fill through the drain valve to keep aeration to a minimum and vent the lop of the tank to allow the air to escape. Be sure that valves and pipe connections between the main tank and any Inerteen filled compartments arc open for free circubtion of gas and liquid. Otherwise, trapped air or cas may cause the Inerteen level in some parts of the transformer to be below the safe operating level. If it is necessary to fill a transformer out-of doors. particularly on a damp day. care should be taken to prevent the entrance of moisture. In order to avoid condensation the temperature ina'de the unit should be kept several degrees above the outside air temperature. The tank and compartments, if any. should be filled at ambient temperature to the point on the gauges marked M25* - Liquid Level." If the ambient varies greatly from 25C (77F) when filled, the Inerteen level should be checked when the average fluid temperature is 25*C. sufficient Inerteen should be added to or drained from the tank to bring the level to the proper height. The transformer should never be operated or left standing, even out of service without the Inerteen level being indicated on the gauge. Filling Under Vacuum. Lntrapped air is a po tential source of trouble in all liquid filled irar.stcrmers. Therefore, n is desirable to fill all Inerteen transformers under a full v.uuwm. This is dor.e for the transformers shipped from the factory and should be done where practicable when transformers are filled in the field, provid ing the transformer cases have been so designed. If the eases have not been designed for full vacuum and it is imperative to get the maximum winding impulse strength inunediatelv. the trans formers should be filled with Inerteen under full vir.u.T. by placing them m an au\di.:r> vacuum Where purchaser does not have an established technic .ie for vacuum filling, the foK.swing proced-ref may be used whether vaemnr. i applied 1THFC00026525 - "\ " 753862 I ]) directly to the transformer or the complete transformer is placed in an auxiliary vacuum tank. 1. Apply and maintain continuously a vac* uum of at least 28 inches of mercury for at least one-half hour to units rated 25KV and below, or for four hours to units above 25KV. 2. While retaining the vacuum, slowly fill with Inerteen to the normal 25C level or with approximately 90% of the required amount where it is impossible to gauge properly. 3. Maintain the specified vacuum for at least one-halfhour after filling. 4. Adjust Inerteen to normal level and seal the transformer tank. Do not reopen until the temperature at the top of the fluid is equal to or higher than the ambient temperature in order to avoid condensation on the surface of the Inerteen. In those cases where the transformers are not filled under vacuum, full voltage should not be applied to the windings for at least 24 hours after the Inerteen has been put into the case. This time is necessary to allow the air bubbles to escape. PtACINC IN SERVICE Pressure Testing. All Inerteen transformers are pressure-tested at the factory and shipped free of leaks. After installations and before voltage is applied, it is desirable to pressure-test each transformer, especially if any fittings or covers have been removed and replaced during installa tion. Compressed dry nitrogen or dry air may be used for the purpose. It is recommended that the space above the Inerteen be blown out with dry nitrogen, then close all vents and apply a pressuretest of five pounds per square inch for a period of six to eight hours. The lest pressure can best be limited by the use of a pressure regulator attached to the nitrogen c\ limier. A check for leaks of joints above the Inerteen level may be made by painting them with a solution of soap and glycerin and watching for gas bubbles. At the conclusion of the test the internal pressure should be returned to normal by momentarily venting the gas space. High Altitude. Where transformers are to be used at a high altitude (more than 3000 feet above sea level) a fitting above the liquid level should be opened to equalize the internal and external pressures at a temperature of approximately IS* C before placing the transformer in service. Grounding Transformer Tank. Regardless of the type of foundation or floor on which a trans former is to rest, the tank should be definitely and permanently grounded to eliminate the possi bility of obtaining static shocks or being injured by accidental grounding of a winding to the case. A ground pad or lug is always provided near the bottom of the tank for the purpose of connecting the ground :d lead. CAUTION: A good low-resistance ground is necessary for adequate protection --a poor ground may be worse than none at alt. Grounding Low Voltage Winding. Every effort is made in insulating transformers to guard against any dunce of breakdown between high voltage and low voltage windings: however, in order to be absolutely safe, it is advisable that low voltage circuits with which persons may come in contact be grounded. The maximum voltage that can lc obtained to ground is then limited to the normal voltage that exists between the grounded point and the line: this is true c u n though the high voltage and low voltage windings become con nected electrically. In grounding the winding, the neutral point should be used if it is available. When trans formers operate on single phase circuits with the middle point of the low volt.ige, the maximum voltage that can exist between any part of the low voltage circuit and ground is one-half of the low voltages. MAKING CONNECTIONS A diagram, usually on the metal instruction plate attached to the side of the case, shows the pn|vr v -r-fi^SCOOO 26526 753863 : V 14 power terminal connections to be made for various voltages. Care should be taken to see that all connections and only those shown are prop erly made, for a wrong connection may cause severe djmage. Some installations require an auxiliary source of power or control leads to be wired to terminals at the transformer; a wiring diagram, either a separate drawing or included as part of the outline drawing, shows the connections to be nude. Voltage Application. When voltage is first applied to the transformer, it should, if possi ble, be brought up slowly to its full value so that any wrong connection or other trouble may be disclosed before damage can result. After full voltage has been applied successfully, the transformer should be operated without load for a few hours. It should be kept under close observation during this time and also dur ing the first few hours while loaded. should be taken out of service and given a thorough inspection. Any symptoms, such as unusual noises, high or low Incrtccn levels, operation of re lief device, etc., should be investigated at once. Transformers which have been subjected to unusually severe operating conditions, such as overloads, frequent short circuits, or special units should be inspected at least once a year. This can usually be done adequately by lowering the Inerteen level and inspecting *ith a light through the manhole. Before this inspection is made, the Inerteen should be allowed to cool to reduce the amount of Inerteen fumes given off which arc quite objectionable and should not be inhaled. During periodic inspection, all accessories . should be inspected to see if they are operating properly. INSPECTION It is desirable that periodic inspections of lnerteen apparatus be made and that samples of Inertecn be taken from each and from all com partments of any apparatus and tested after a short period of service. See section on Sampling and Inspection. Any increase in operating temperature d normal load should be investigated and if the cause cannot be determined, the transformer CAUTION; Never enter a vault or any other confined area in which a transformer relief device has been known to operate or in which a transformer has failed, until the area has been thoroughly ventilated. Then enter cautiously, with another person in attend ance. The pungent, some* hat irritating fumes of hydrogen chloride are easily de tected and can serve as a gi. *de in entering the enclosure. s * NT - NPC00026527 753864 * # Memorandum ( -i NPC00026528 753865 t c Westinghouse THE IEAOER OF THE TRANSFORMER INDUSTRY b *9 \ ( NPC00026529 753866