Delta Star mobile transformers and mobile substations provide the capabilities to quickly restore electrical service following an outage caused by a storm or other disaster, provide temporary new service while permanent facilities are being constructed, or replace existing equipment during regularly scheduled maintenance. Delta Star engineers determine specific customer needs and exact equipment integration requirements prior to the design and manufacture of each quality mobile unit. Custom designed and built to order, each unit also has a wide variety of accessories and equipment options available to provide even greater capability and operating flexibility. Quick response installation time and equipment reliability are just two of the reasons why Delta Star units place far ahead of the competition.
Delta Star mobile transformers and mobile substations are specifically designed and built for maximum mobility and safety. Mobile transformers are designed to withstand the additional road travel requirements and are welded to a trailer with air-ride suspension for maximum stability and protection for safe movement over uneven pavement or off-the-road travel. Mobile units are also designed to meet state and federal highway requirements.
A mobile substation is formed by adding other equipment, such as high voltage circuit breaker or circuit switchers, low voltage switch gear, fuses, and other special applications requirements to the mobile transformer. The major engineering objective is to design and build a mobile Delta Star substation to meet all customer requirements and still provide ease of installation and operation after being transported to the site. A Delta Star mobile substation can be put into service within hours.
Features
Core
Each Delta Star power transformer core is designed to provide the accuracy and consistency necessary for high efficiency and superior performance.
Only the highest quality grain-oriented silicon steel is used to make step-lap laminations cut to engineering design specifications. After the laminations have been precisely cut and assembled on a building jig for accurate positions, experienced personnel assemble the core clamping structure so that the mass of steel is supported in a cradle-like method. The structure eliminates undue stress on the laminations while providing maximum strength to withstand the forces of shipping and short circuit.
Coil
Delta Star engineers custom design coils with the optimum winding configuration to meet the specific requirements of each application. Advanced engineering ensures high reliability, mechanical, and electrical integrity. Specific requirements such as non-standard loading conditions or low-impedance are accommodated in design.
All Delta Star windings are designed and built with the inherent strength to withstand the axial and radial components of short circuit stress. The design calculations have been developed and proven by short circuit test results. Only the best grade electrical conductors and materials are used to make the coils of Delta Star power transformers.
Tank
Because long-term tank integrity is absolutely essential for the reliability and long life of a transformer, Delta Star fabricates transformer tanks to meet the highest standards of quality and craftsmanship. All tanks and covers are fabricated of high quality plate steel to withstand full vacuum. Tank corners are bent instead of welded to assure strength, reliability, and eliminate stress leaks. Welding is accomplished in a double shielded "mig" process that provides continuous welds. All corners are radius ground to allow complete paint adhesion.
A leading paint manufacturer, after many years of research and development, has developed a special transformer paint formulated to withstand exposure to extreme weather conditions. Prior to painting, the metal surface is shot-blasted to provide superior cleanliness and paint bonding.
Control
At Delta Star, the control panel is given special emphasis in design and construction as the critical part to monitor, control, and protect the whole power transformer unit. Delta Star produces a superior control panel that enables the user to accurately monitor and adjust the operation of the transformer.
Sensors are located at various points in the transformer to accurately monitor temperature, fluid levels, and other conditions of the unit at all times. Alarms and visual instruments alert personnel in the event of an abnormal condition for correction or further troubleshooting. Remote monitoring is also available.
Testing
Delta Star engineers conduct all routine tests, in accordance with ANSI/IEEE on every transformer manufactured. In addition to these routine tests, the Quality Control team can perform all ANSI/IEEE impulse tests, switching surge tests, partial discharge, temperature rise, and power factor tests. Knowing that load and no-load losses over time can be a primary cost consideration, Delta Star provides certified test reports on every transformer and supports it with an instrument calibration program traceable to standards (NIST).
Service
Delta Star provides a full range of power transformer services through a highly qualified force of readily available field service engineers and technicians. Troubleshooting, technical assistance, and emergency repairs are prime examples of these services. Complete Delta Star services translate into cost savings, equipment compatibility, one source service responsibility, requirements coordination, and availability of computerized replacement parts inventory. Delta Star enables customers to conduct business with confidence and without interruption.
LTC/DETC
Tap changing equipment used on Delta Star transformers is available for off-load (manual) or on-load (automatic) applications. Both type units have been developed and improved to exceed the highest industry standards to provide long service life with minimum maintenance requirements.
Manual DETC units feature silver plated contacts and operate under spring-pressure to ensure positive contact. The tap changing control lever is operated externally. It clearly indicates the tap position and can be pad locked in the locked position.
Automatic LTC units maintain the voltage at the load to the required level, automatically utilizing advanced technical design, and the most durable high efficiency, long contact life, and maintenance-free operation (vacuum-reactor or resistor types are available).
Mobile Transformers