100-25 March 1995 INSTRUCTIONS Liquid Filled Transformers SAFETY INFORMATION IMPORTANT - READ CAREFULLY WARNING - READ ALL INSTRUCTIONS CAREFULLY PROBLEMS ARISE WHICH ARE NOT COVERED BEFORE ATTEMPTING TO HANDLE, INSTALL, USE OR SUFFICIENTLY FOR THE PURCHASER’S PURPOSES, SERVICE THIS EQUIPMENT. FAILURE TO FOLLOW THE MATTER SHOULD BE REFERRED TO THE INSTRUCTIONS COULD RESULT IN SEVERE INJURY, NEAREST SALES OFFICE OF MGM TRANSFORMER DEATH, OR PROPERTY DAMAGE. COMPANY. CAUTION - THE EQUIPMENT COVERED BY THESE ALL APPLICABLE SAFETY PRACTICES INCLUDING, BUT INSTRUCTIONS SHOULD BE INSTALLED, OPERATED, NOT LIMITED TO, OSHA, NFPA, ANSI, REGIONAL AND AND SERVICED ONLY BY COMPETENT TECHNICIANS LOCAL SAFETY CODES, SAFE WORKING PRACTICES FAMILIAR WITH GOOD SAFETY PRACTICES. THESE AND GOOD JUDGMENT, AS THEY MAY BE APPLIED TO INSTRUCTIONS ARE WRITTEN FOR SUCH PERSONNEL THIS TYPE OF EQUIPMENT MUST BE USED AND AND ARE NOT INTENDED AS A SUBSTITUTE FOR OBSERVED BY ALL PERSONNEL WHEN INSTALLING, ADEQUATE TRAINING AND EXPERIENCE IN SAFE OPERATING AND MAINTAINING THIS EQUIPMENT. PROCEDURES FOR THIS TYPE OF EQUIPMENT. DO NOT MAKE ANY CONNECTIONS THAT ARE NOT THESE INSTRUCTIONS DO NOT PURPORT TO COVER AUTHORIZED BY THE NAMEPLATE OR CONNECTION ALL DETAILS OR VARIATIONS IN EQUIPMENT NOR TO DIAGRAMS. PROVIDE FOR EVERY POSSIBLE CONTINGENCY TO BE MET IN CONNECTION WITH INSTALLATION, TRANSFORMER MUST BE PROPERLY GROUNDED OPERATION OR MAINTENANCE. SHOULD FURTHER BEFORE ENERGIZING. INFORMATION BE DESIRED OR SHOULD PARTICULAR MGM TRANSFORMER COMPANY 323-726-0888 5701 SMITHWAY STREET • CITY OF COMMERCE, CA 90040 FAX 323-726-8224 - 1 - Liquid Filled Transformers 100-25 March 1995 ADDITIONAL SAFETY NOTES - READ CAREFULLY 1. KEEP THIS INSTRUCTION BOOK AVAILABLE TO WHILE ENERGIZED WILL RESULT IN INTERNAL ALL PERSONS RESPONSIBLE FOR INSTALLATION, ARCING AND POSSIBLE SEVERE PERSONAL INJURY MAINTENANCE, AND OPERATION OF THE AND/OR DAMAGE TO THE TRANSFORMER. TRANSFORMER. 7. WARNING---THE TRANSFORMER TANK 2. WARNING---ALWAYS DE-ENERGIZE AND CONTAINS INSULATING LIQUID AND THE GAS SPACE LOCK OUT THE POWER SUPPLYING THIS NORMALLY CONTAINS NITROGEN. TO AVOID DEATH EQUIPMENT BEFORE MAKING ANY REPAIRS OR BY SUFFOCATION DO NOT ENTER TANK UNLESS AN PERFORMING ANY MAINTENANCE. FAILURE TO DO ANALYSIS OF THE AIR IN THE TANK SHOWS AT SO COULD RESULT IN PERSONAL INJURY, DEATH, LEAST 19.5% OXYGEN CONTENT. OR PROPERTY DAMAGE. 8. WARNING---THE TRANSFORMER TANK MAY 3. DANGER---WHEN THE TRANSFORMER IS BE UNDER HIGH PRESSURE. DO NOT REMOVE ANY ENERGIZED, THE BUSHINGS AND COMPONENTS BOLTS, PLUGS OR OTHER ACCESSORIES WITHOUT CONNECTED TO THE BUSHINGS, BOTH INTERNALLY FIRST RELIEVING THE INTERNAL TANK PRESSURE. AND EXTERNALLY, ARE AT HIGH VOLTAGES. FAILURE TO RELIEVE THE PRESSURE COULD COMING TOO CLOSE TO LIVE PARTS COULD RESULT RESULT IN THE PART BEING REMOVED BECOMING A IN DEATH BY ELECTROCUTION. HAZARDOUS FLYING OBJECT. PERSONNEL COULD BE INJURED BY THE FLYING OBJECT. INSULATING LIQUID OR VAPOR COULD BE EXPELLED FROM THE TANK CREATING A POSSIBLE FIRE HAZARD. 4. DANGER---THE CONTROL CABINET AND ACCESSORIES CONNECTED TO THE CABINET CONTAIN HIGH VOLTAGES. ALL POWER SOURCES SUPPLYING THE CABINET COMPONENTS MUST BE 9. WARNING---THE TRANSFORMER MUST HAVE DISCONNECTED AND LOCKED OUT BEFORE ANY THE CORRECT AMOUNT OF INSULATING LIQUID INSPECTION, MAINTENANCE OR REPAIRS ARE MADE WHILE ENERGIZED. FAILURE TO MAINTAIN THE ON THE CONTROL CABINET AND IT’S COMPONENTS. INSULATING LIQUID AT THE PROPER LEVEL COULD FAILURE TO DO SO COULD RESULT IN SEVERE RESULT IN PERSONAL INJURY, DEATH, OR PERSONAL INJURY, DEATH, OR PROPERTY PROPERTY DAMAGE. DAMAGE. 10. CAUTION---IF THE PRESSURE-VACUUM 5. WARNING---CURRENT TRANSFORMER GAGE READS ZERO AND DOES NOT CHANGE UNDER SECONDARY TERMINALS MUST BE SHORT DIFFERENT TRANSFORMER LOADING CONDITIONS, CIRCUITED OR CONNECTED TO A LOAD WHILE THE THE TRANSFORMER SHOULD BE CHECKED FOR TRANSFORMER IS ENERGIZED. IF THE SECONDARY POSSIBLE LEAKS. A LEAK WILL ALLOW MOISTURE TERMINALS ARE OPEN CIRCUITED, HIGH VOLTAGES AND AIR TO ENTER THE TRANSFORMER WHICH WILL ARE PRESENT AT THE TERMINALS. FAILURE TO DEGRADE THE INSULATION AND LIQUID. THE LIFE PROPERLY CONNECT THE SECONDARY TERMINALS OF THE TRANSFORMER COULD BE REDUCED IF TO A CLOSED CIRCUIT COULD RESULT IN SEVERE LEAKS ARE NOT REPAIRED. PERSONAL INJURY, DEATH, OR PROPERTY DAMAGE. 6. CAUTION---THE TAP CHANGER MUST ONLY BE OPERATED WHEN ALL POWER SUPPLYING THE TRANSFORMER IS DISCONNECTED AND LOCKED OFF. ATTEMPTING TO OPERATE THE TAP CHANGER - 2 - Liquid Filled Transformers 100-25 March 1995 TABLE OF CONTENTS SECTION DESCRIPTION PAGE 1.0 RECEIVING 4 2.0 HANDLING 4 3.0 STORING 4 4.0 INSTALLATION 5 5.0 VAULT VENTILATION 6 6.0 GASKETS 6 7.0 ACCESSORIES 7 8.0 BUSHINGS 10 9.0 INSULATING LIQUIDS 10 10.0 FILTERING AND DRYING 12 11.0 MAINTENANCE 13 12.0 RENEWAL PARTS 13 13.0 SERVICE 13 14.0 INSULATING FLUID SPECIFICATIONS 14 - 3 - Liquid Filled Transformers 100-25 March 1995 1.0 RECEIVING attention to the tap changer, bushings, electrical connections, leads, insulation, coils, etc. Liquid filled transformers are usually shipped F.O.B. factory and are normally completely assembled, liquid- If any internal damage is found, include it on the damage filled and ready to install. Immediately upon receipt of the claim with the transportation company and notify the equipment, examine the transformer and any separate nearest Sales Office of MGM Transformer Company for parts packages for any damage which may have occurred further instructions. during shipment. If injury or rough handling is evident, file a damage claim with the transportation company and After the internal inspection is complete, replace the notify the nearest Sales Office of MGM Transformer handhole or manhole cover and gasket and purge the gas Company. space with dry nitrogen. Check the tank for leaks-See Section 4.3. Tighten any parts which may have worked loose, such as nuts and leads and check the materials against the 2.0 HANDLING shipping list for possible shortages. Lifting hooks are provided for lifting the complete A notation should be made of the reading of the pressure transformer. In addition, where necessary, additional lifting vacuum gage and the liquid level gage. eyes are supplied for lifting other various parts. Lift the transformer by utilizing all four of the main lifting hooks, An internal inspection is not required unless there is using cables long enough to obtain cable pull angles not evidence of rough handling, tank damage, damaged over 30 degrees from vertical. When lifting the accessories or an inoperative tap changer. transformer, the cover should be securely fastened in place to prevent buckling the tank walls. All four lifting If an internal inspection is required, the following hooks must be used when lifting the complete transformer. instructions should be adhered to: 1) Do not attempt an internal inspection in an area The transformer may be skidded or moved on rollers. unprotected from the weather during precipitation or in an When using rollers, be sure that a sufficient number are area where the air may contain dirt or other particles. Any used to distribute the weight. foreign matter entering the inside of the transformer could cause a failure. Refer to the transformer outline drawing for the location of 2) The liquid temperature should be equal to or greater the jacking provisions. Do not attempt to move the unit by than the outside air temperature. If it is not, moisture placing jacks under drain valves, cooling radiators or other condensation may degrade the dielectric strength of the attachments. insulting fluid. 3) Before attempting to unbolt the handhole or manhole At least two jacks should be used and adjacent corners cover, bleed off any internal pressure to prevent the bolted raised simultaneously to avoid damaging the base cover from becoming a hazardous flying object. assembly. WARNING---The transformer tank may be under high pressure. Do not remove any bolts, plugs or Liquid filled transformers should always be handled in the other accessories without first relieving the normal upright position and in no case tilted more than 15° internal tank pressure. Failure to relieve the from the vertical, unless instructions have been given to the contrary. pressure could result in the part being removed becoming a hazardous flying object. Personnel Bolt-on terminal chambers, when provided, can be could be injured by the flying object. Insulating removed to facilitate moving the transformer. liquid or vapor could be expelled from the tank creating a possible fire hazard. 3.0 STORING Internal pressure may be relieved by manually operating the pressure relief valve or opening the gas sampling Before placing a transformer in storage, make sure the valve and waiting until the internal pressure equalizes. insulating liquid is at its proper level, add dry nitrogen in 4) After removing the handhole or manhole the gas space until the pressure reaches 3 psi (20.7 kPa) cover, ventilate the gas space with dry air to and then seal the unit. Before placing a transformer in purge the nitrogen gas it contains. WARNING--- service after a period of storage, relieve the internal gas The gas space normally contains nitrogen. to avoid pressure by venting to the atmosphere. See paragraph on death by suffocation do not enter tank unless an "Venting". Make a through inspection of the transformer analysis of the air in the tank shows at least 19.5% before energizing. oxygen content. Transformers stored for use as spares should be After removing the handhole check for any internal maintained in the same condition as those in service. damage which might have occurred in shipment. Pay close Make periodic inspections of the liquid level, its dielectric - 4 - Liquid Filled Transformers 100-25 March 1995 strength, and when furnished, fans, alarms, and control Transformers having internal terminal boards are normally circuits. Also check the pressure gauge to make sure the shipped connected for the highest rated voltage.