Document 2.4.
Document 2.4.54 Revision 0 July 2006 Small Power Substation Transformers ! IMPORTANT SAFETY INFORMATION ! Read these instructions carefully before proceeding with installation, operation, or maintenance of this equipment. Small power transformers contain extremely hazardous voltages. To prevent death, serious personal injury, or property damage, all information in these instructions should be read and observed.
TABLE OF CONTENTS IMPORTANT SAFETY INFORMATION .................................................................................................................................................................. 2 IMPORTANT INFORMATION ABOUT THESE INSTRUCTIONS ............................................................................................................................. 2 RECEIVING INSPECTION ........................................................................................................
Document 2.4.54 Revision 0 July 2006 Small Power Substation Transformers RECEIVING INSPECTION These instructions apply to substation transformers manufactured by Howard Industries. It is important to read the safety information on page 2 before attempting any installation, operation, or maintenance activities.
Document 2.4.54 Revision 0 July 2006 Small Power Substation Transformers HANDLING Lifting Lifting hooks are provided near the top of the transformer tank for lifting. All four lifting hooks must be used simultaneously. The transformer must not be lifted from any points other than the provided lifting hooks. It is recommended that spreader bars be used to keep the lifting cables nearly vertical, reducing the likelihood of tank deformation or damage to painted surfaces.
Document 2.4.54 Revision 0 July 2006 Small Power Substation Transformers STORAGE Transformer Storage Transformers can be stored if properly prepared. It is recommended that stored transformers be completely assembled. Prior to storage, transformers should be pressure tested according to the instructions on page 9 (Pre-energization Tests and Checklist). The gas space above the insulating fluid should be pressurized with dry nitrogen to a pressure between two and three PSIG.
Document 2.4.54 Revision 0 July 2006 Small Power Substation Transformers INSTALLATION Location and Mounting The transformer should be mounted on a level concrete foundation of sufficient strength to support the weight of the completely assembled transformer. If the transformer is not level, insulating fluid may not circulate properly through the cooling assembly, possibly causing overheating and reduced transformer life.
Document 2.4.54 Revision 0 July 2006 3. Pressurize the headspace to 4 PSIG and check for fluid leaks. This pressure should be maintained for at least four hours. When the internal inspection is complete, reseal the tank and refill with fluid (if any was removed prior to inspection). The gas space should be filled with dry air or dry nitrogen to 2 PSIG. Contact the Howard Substation Transformer Division if any internal damage is found during the internal inspection.
Small Power Substation Transformers Installation of Surge Arresters Surge arresters should be installed according to the following instructions and the outline drawing. ! WARNING: FAILURE TO FOLLOW THESE INSTRUCTIONS COULD RESULT IN SEVERE PERSONAL INJURY, DEATH, OR EQUIPMENT DAMAGE. 1. Carefully unpack and inspect surge arresters for damage. 2. When installing arresters, all mounting feet must be flush with the mounting surface before tightening bolts. Use shims if necessary. 3.
Document 2.4.54 Revision 0 July 2006 8. Delta/Wye and Series/Multiple Switch Settings. Check delta/wye and series/multiple switch settings to make sure they are set correctly. If these connections are made using an internal terminal board, check to ensure that these connections are made properly according to the chart on the transformer nameplate. If the transformer is equipped with an internal terminal board, refer to page 7 for instructions and warnings prior to opening tank. 9. Grounding.
Document 2.4.54 Revision 0 July 2006 Small Power Substation Transformers COMPONENTS AND ACCESSORIES Refer to the outline drawing for a list of accessories furnished with the transformer. Transformer Nameplate A nameplate is supplied on each transformer according to ANSI standard C57.12.00. The nameplate provides certain physical and electrical information about the transformer. Control Cabinet Refer to the wiring diagram for a description of electrical circuits inside the control cabinet.
Document 2.4.54 Revision 0 July 2006 PRDs can be supplied with an optional alarm/signal switch. Refer to the schematic wiring diagram furnished with the transformer. Fluid Level Gauge The fluid level gauge indicates the fluid level inside the tank. The transformer tank is filled with fluid at the factory to the normal level at a reference temperature of 25°C. Fluid Temperature Gauge The fluid temperature gauge indicates the fluid temperature at the top of the fluid column.
Document 2.4.54 Revision 0 July 2006 Small Power Substation Transformers ! DANGER: ALWAYS DE-ENERGIZE THE FAN CIRCUIT WHEN INSTALLING OR PERFORMING MAINTENANCE ON FANS. IN ADDITION, DE-ENERGIZE THE TRANSFORMER WHEN IT IS POSSIBLE TO COME CLOSE TO LIVE PARTS. FAILURE TO DO SO COULD RESULT IN SEVERE PERSONAL INJURY OR DEATH. FAN GUARDS ARE FURNISHED AND INSTALLED AT THE FACTORY TO PREVENT ACCIDENTAL CONTACT WITH ROTATING FAN BLADES. DO NOT REMOVE FAN GUARDS OR ALLOW PERSONNEL TO REACH INSIDE A GUARD.
Document 2.4.54 Revision 0 July 2006 High-Voltage Bushings High-voltage bushings are typically shipped installed in the unit. If the bushings were removed for shipment, install the bushings per the manufacturer’s guidelines. ! WARNING: DO NOT EXCEED THE CANTILEVER LOAD RATING OF THE BUSHING. GREATER LOADS MAY CAUSE BUSHING DAMAGE THAT COULD RESULT IN SEVERE PERSONAL INJURY, DEATH, OR PROPERTY DAMAGE. Draw-lead bushings usually require no maintenance except as described on page 15.
Document 2.4.54 Revision 0 July 2006 Small Power Substation Transformers MAINTENANCE ! DANGER: THE TRANSFORMER MUST BE DE-ENERGIZED BEFORE BEGINNING ANY MAINTENANCE WORK. FAILURE TO DO SO COULD RESULT IN SEVERE PERSONAL INJURY, DEATH, OR PROPERTY DAMAGE. It is the responsibility of the owner to inspect, maintain, and keep the transformer in proper operating condition. Report all issues during the warranty period to the Howard Substation Transformer Division.
Document 2.4.54 Revision 0 July 2006 Gaskets Visually check all gaskets for cracking or other signs of deterioration. Replace as necessary. When replacing a gasket carefully clean mating surfaces to remove any rust, dirt, transformer fluid, old gasket material, or other contamination that might prevent a good seal. Use an appropriate gasket cement when installing new gaskets. Do not reuse old gaskets. Six months after replacing a gasket, check and retighten if necessary.
Document 2.4.
Instructions for Installation, Operation, and Maintenance of Substation Transformers Through 10,000 kVA Document 2.4.54, Revision 0 (July 2006) Copyright © 2005, Howard Industries, Inc. Laurel, Mississippi Telephone: 601-425-3151 Fax: 601-649-8090 Web: howardtransformers.
