Federal Pacific Epoxy Shielded Transformers

VPI & Epoxy Shielded Dry-Type Transformers

Vacuum pressure impregnated (VPI) transformers combine a performance proven dry-type transformer design with the environmental protection of a polyester coil encapsulations process. This combination ensures reliable transformer operation in hostile environments containing moisture, dust, dirt, chemicals and other contaminants.

The VPI process fully penetrates and seals the coils into a high strength composite unit for a complete environmental protection. Since the coil protection is created using vacuum pressure impregnation rather than molding, maximum design flexibility is achieved to allow conformance to the most stringent application requirements.

The vacuum impregnation of the varnish eliminates winding voids to reduce essentially to zero any corona generation due to insulation voids. Corona, particularly in conjunction with corrosive environments, accelerates the degradation of the insulation materials and will cause the transformer to fail prematurely.

VPI and Epoxy Shielded transformers are available in sizes from 7.5 KVA to 10,000 KVA and voltages from 600 through 34,500 volts. The most popular standard KVA and voltages are available, as well as custom sizes.

Benefits: Epoxy Shielded vs. Cast Coil”

• Lower initial cost

• Flexibility of design

• Elimination of cracking epoxy

• Higher thermal overload Cast = 17% @ 80/115 degree C rise VPI = 30% @ 80/150 degree C rise

• Less weight for easier handling and installation

• Smaller dimensions to save valuable floor space

• Outstanding environmental protection

The Product
A high quality electrical transformer with excellent resistance to dust, fumes and moisture. Superior resistance to cracking from thermal cycling. Maximum design flexibility. All at less cost than cast coil transformers.

The Material
High performance 100% solid, precatalized, solventless varnish. This varnish, when applied, imparts a clear, tough, high bond strength coating to the coil assemble. It also adds high dielectric strength as well as mechanical bong strength and unparalleled thermal endurance.
Coil Construction
Circular coil construction is used to assure proper ventilation and maximum short circuit strength. Coils are constructed using a 220 degree C Nomex* insulation system that for many years has had proven performance in dielectric strength, temperature stability and long life. This high voltage coils are wound directly over the low voltage coils to form a complete assembly. The coil assembly is completely insulated and mechanically braced to pass all ANSI standard test prior to encapsulation. The coil does not depend on the encapsulation process and its material to provide electrical and mechanical strength. The VPI process provides an additional margin of insulation and strength.

Epoxy Shielded Transformer
The Epoxy Shielded Transformer is a product that is more superior to the more expensive and larger cast coil transformer. The design of the Epoxy Shielded Transformer has the same benefits of unequaled environmental protection, high Basic Impulse Levels, low sound, and superior short circuit strength, as cast coil transformers. The Epoxy Shielded transformers have the added benefits of lower cost, greater design flexibility, elimination of cracking, higher thermal overloads, smaller dimensions and less weight.

The design begins with a quality VPI transformer. To this 2 mils minimum of modified epoxy varnish is added with the result being a premium transformer ready to handle the really tough environments. The Epoxy Shielded Transformer is ideal for environments polluted with chlorides, acids, alkalis, salt water and high humidity.

A high viscosity (40-60) scc. #4 Fordcup) formulated epoxy is used. This specially formulated epoxy is designed for greater film dry thickness than most epoxies in use today. The epoxy used has a high percentage of solids, yet has a relatively low cure weight. This unique combination allows high mechanical bond strength and a low overall unit weight.

Where your environmental concerns are the greatest, specify the best epoxy transformer on the market today.

Specification Guide
The transformer (s) shall be open dry-type with both primary and secondary coils encapsulated with polyester resin using a vacuum pressure impregnation (VPI) process (optional VPI with Epoxy Shield). The transformer shall be fire resistant, and cooled by the natural circulation of air through the windings.

The unit shall be mounted in an indoor (optional outdoor/NEMA 3R) ventilated enclosure, finished in the manufacturer’s standard light gray paint.

The transformer will be designed, manufactured and tested in accordance with applicable ANSI, NEMA and IEEE standards.

Conductor Material
The conductor shall be electrical grade aluminum (copper)

Insulation Material
All insulation materials for the primary and secondary coils shall be rated for continuous 220 degree C operation.

Optional Forced Air Cooling
A complete forced air cooling system shall be provided for automatically increasing the self cooled rating by 33-1/3%. The system shall contain 120 VAC single phase fans and a control panel with indicating lights, temperature indicator, fan position test switch and alarm mode selector switch.

Coil Assembly
The high and low voltage coils shall be round, concentrically wound as an integral assembly. The insulated coil assembly shall be capable of passing all standard ANSI and NEMA tests, including impulse test before the coils are encapsulated.

High Voltage Taps
Taps shall be terminated at the coils and equipped with provisions for changing taps under de-energized conditions.

Encapsulation System
The coil assembly shall be encapsulated using a VPI process. This process shall utilize heat, vacuum and pressure to completely seal and bind the windings. The VPI encapsulating material shall be solventless polyester. (An additional shielding of high viscosity insulating epoxy may be applied after the VPI process for protection against environments containing corrosive elements).

Core Structure
The core structure shall be on non-aging, cold rolled, grain oriented, high permeability silicon steel. All core laminations shall be free of burrs and stacked without gaps. The core framing structure shall be of rigid construction to provide full clamping pressure upon the core and provide support points for the coils.

Cores to be constructed in a butt-lap construction, or as an option, a miter type construction.

Vibration dampening pads shall be provided to isolate the core and coil assembly from the base structure.

The outside surfaces of the core shall be varnish dipped to protect against corrosion.

Enclosure
The enclosure shall be constructed of 12 gauge sheet steel equipped with removable panels for access to the core and coils on the front and rear. Ventilated openings shall meet NEMA and IEEE standards. The enclosure shall include provisions for rolling, skidding, jacking and lifting. Finish to be an electrostatic powder coating using a U.L. approved outdoor polyurethane paint.

Sound Level
The transformer shall be designed to meet or excel the standards for dry-type transformers per ANSI and NEMA standards.

Tests
Each transformer shall be tested in accordance with IEEE C57.12.91.The one stop resource for everything about power transformers. Consider this site your location to get all of your power transformer questions answered.

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• Federal Pacific Unit Substation Transformers
• Federal Pacific VPI  Epoxy Shielded Transformers
• Federal Pacific K-Factor Transformers

 Power Transformer Information:

 Power Transformer Manufacturer

• ACME Transformers - With Acme Electric being in business over 80 years, they have always believed in offering there customers superior service, quality and technical expertise in the transformer market.
• AMVECO Transformers - AMVECO designs and manufactures toroids transformers, current transformers, and auto transformers. Most AMVECO products are custom designed utilizing their state-of-art proprietary CAD programs.  The AMVECO engineers can quickly generate designs in a matter of hours, if needed.
• Federal Pacific Transformers -  Federal Pacific is a division of Electro- Mechanical Corporation, a privately held, American owned company founded in 1958. Federal pacific offers dry-type transformers from .050 KVA through 10,000 KVA single and three phase, up to 34.5 KV, 150 KV BIL with UL approval through 15 KV.
• Marcus Transformer - Ever since they opened their doors for business a half a century ago, they have been a leader in innovative transformer design. As a family-owned company they are proud of the reputation they have earned for making quality-built transformers that deliver exceptional performance and savings.
• Hammond Transformers -  Hammond Manufacturing was founded in 1917 in Guelph, Ontario, Canada. In the last 3 decades it has expanded to the US and the international markets offering many types of power transformers. 
• TEMCo Transformers - TEMCo Transformer, a family-owned business which has been manufacturing and distributing electrical products since 1968. They focus on transformers that significantly reduce power consumption over 30 percent compared to competitive makes.
• GE Transformers - GE has been a key player in the energy industry for more than a century.  Since the installation of their first steam turbine in 1901. They have become number one provider of high-technology power generation and distribution equipment.
• Jefferson Electric Transformers - Jefferson Electric has been a pioneer and innovator of magnetic products since 1915. Jefferson broad line of dry-type transformers are backed by quality assurance systems so stringent that each and every unit gets thoroughly tested before it goes out there door.
• More power transformer brands - Check out more companies by clinking this link.

 Power Transformer Types

• Distribution Transformers - Distribution transformers are generally used in electrical power distribution and transmission power. This class of transformer has the highest power, or volt-ampere ratings. and the highest continuous  voltage rating.
• Substation Transformers - Substation Transformers are large devices which usually weigh tens of thousands of pounds.   They are filled with tens of thousands of gallons of heat transfer fluid.  Although they are typically 99.8% efficient in the transforming of electricity from one voltage to another, processing hundreds of Mega Volts-Amps of electricity force the liberation of hundreds of BTUs per second.
• Medical Grade Isolation
   Transformer - Medical Grade Transformers generally refer to the transformers used in medical devices as well as hospital, biomedical and patient care equipment. There are a number of strict safety rules, guidelines and laws governing the design, construction and the test of these transformers.
• Drive Isolation Transformer - They are used to isolate a drive from a main power line to prevent the transmission of harmonics that the drives produce back into the power line.  They stop drive harmonics from disrupting computers and other sensitive equipment.
• Toroidal Transformers - Toroidal Transformers are more efficient than the cheaper laminated EI types of similar power level. Some of the advantages are smaller size, lower weight, less mechanical hum, (making them superior in audio amplifier), low-off-load loss.

 Power Transformer Types

• Step-Up Transformers - A Step-Up Transformer is one whose secondary voltage is greater than its primary voltage.  This kind of transformer "steps up" the voltage applied to it. -
• Step-Down Transformers - A Step-Down Transformer is  designed to reduce voltage from primary to secondary.  They can range from sizes from .05 KVA to 500 KVA
• Isolation Transformers - An Isolation Transformer is a device that transfers energy from the alternating current (AC) supply to an electrical or electronic load.  It isolates the windings to prevent transmitting certain types of harmonics.
• Buck Boost Transformers - Buck Boost Transformers make small adjustments to the incoming voltage. They are often used to change voltage from 208v to 240v for lighting applications.  Major advantages of Buck boost transformers include; low cost, compact size and light weight. 
• High Voltage Transformer - There are many different types of voltage transformers. A High Voltage Transformer operates with high voltages. Typically, these voltage transformers are used in power transmission applications, where voltages are high enough to present a safety hazard.
• Medium Voltage Transformers - A Medium Voltage Transformer can be connected directly to a primary distribution circuit and generally has the most load diversity. These voltage transformers have installation practices that are generally in accordance with application recommendations from the Institute of Electrical and Electronic Engineers (IEEE).
• Low Voltage Transformers - A Low Voltage Transformer is an electrical device that transforms 120 volts (line voltage) into 12 volts or 24 volts (low voltage). Some uses for low voltage transformer are in landscaping lighting.
• Single Phase Transformers - In electrical engineering, single-phase electric power refers to the distribution of electric power using a system in which all the voltages of the supply vary in unison. Single-phase distribution is used when loads are mostly lighting and heating, with few large electric motors.
• Three Phase Transformers - Three Phase Transformers must have 3 coils or windings connected in the proper sequence in order to match the incoming power and therefore transform the power company voltage to the level of voltage needed while maintaining the proper phasing or polarity.
• Custom Transformers - Custom Transformers are designed for a certain performance specifications and size requirements.  The company works with your engineering specification. 
• Industrial Control Transformers - Industrial Control Transformers are used to convert the available supply voltage to the required voltage to supply industrial control circuits and motor control loads.
• Pad Mounted Transformers - Pad Mounted Transformers are usually single phase, or three phase, and used where safety is a main concern. Typical applications; restaurant, commercial building, shopping mall, institutional. 
• Pole Mounted Transformers - Pole Mounted Transformers are used for distribution in areas with overhead primary lines. Outside a typical house one can see one of these devices mounted on the top of an electrical pole.
• Oil Filled Transformers - Oil Filled Transformers are transformers that use insulating oil as insulating materials.  The oil helps cool the transformer. Because it also provides part of the electrical insulation between internal live parts, transformer oil must remain stable at high temperatures over an extended period.
• Dry Type Transformers - Dry-Type Transformers are available for voltages up through 34.5 kV (although the most common upper limit is 15) and KVA ratings up through 10,000 (with 5000 as the usual limit). Dry-type use air as a coolant, lowering health and environmentally concerns.
• Auto Transformers - An Autotransformer is an electrical transformer with only one winding. The winding has at least three electrical connection points called taps. Autotransformers are frequently used in power applications to interconnect systems operating at different voltage classes, for example 138 kV to 66 kV for transmission. Another application is in industry to adapt machinery built for 480 V supplies to operate on the local 600 V supply.
• More power transformer types - Read further about additional transformer types and their uses.

 Power Transformer Term Definitions

• Electrical Transformers - Electrical Transformers are devices used to raise or lower the voltage of alternating current. For instance, power is transported over long distance in high voltage power lines and then transformers lower the voltage so that the power can be used by a business or household.
• Isolating Transformers - An Isolating Transformer is a transformer, often with symmetrical windings, which is used to decouple two circuits.  An Isolation transformer allows an AC signal or power to be taken from one device and fed into another without electrically connecting the two circuits. Isolation transformers block transmission of DC signals from one circuit to the other, but allow AC signals to pass. 
• Transmission Power Lines - A Transmission Line is the material medium or structure that forms all or part of a path from one place to another for directing the transmission of energy, such as electromagnetic or acoustic waves as well as electric power transmission. Components of transmission lines include wires, coaxial cables,  dielectric slabs, option fibers, electric power lines, and waveguides.
• Transformer Voltage - The measure of the amount of force on a unit charge because of the surrounding charge.
• Transformer Phase - Most transformer are either single phase or three phase.
• Transformer Frequency - The transformer cannot change the frequency of the supply. If the supply is 60 hertz, the output will also be 60 hertz.
• Transformer K Factor - Some transformers are now being offered with a k-factor rating. This measure the transformer's ability to withstand the heating effects of non-sinusoidal harmonic currents produced by much of today's electronic equipment and certain electrical equipment.
• Primary Voltage - The coil winding that is directly connected to the input power.
• Secondary Voltage - The coil winding  supplying the output voltage.
• Harmonic Cancellation - Harmonic cancellation is performed with harmonic canceling transformers also known as phase-shifting transformers. A harmonic canceling transformer is a relatively new power quality product for mitigating harmonic problems in electrical distribution systems. This type of transformer has patented built-in electromagnetic technology designed to remove high neutral current and the most harmful harmonics from the 3rd through 21st.
• Weatherproof - Enclosed transformers come with a weatherproof standard set by NEMA.
• Epoxy Encapsulated - A process in which a transformer or one of its components is completely sealed with epoxy or a similar material. This process is normally preferred when a unit might encounter harsh environmental conditions.
• More power transformer terms - Such as inductor, ground fault, core saturation, current transformer, faraday shield, etc.

Related Transformer Products

• Voltage Regulators - A Voltage Regulator is an electrical regulator designed to automatically maintain a constant voltage level.  It may use an electromechanical mechanism, or passive or active electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages.
• AC Line Reactor - AC Line Reactors is a three phase transformer used in conjunction with AC variable frequency and DC motor drive. They are a bi-directional protective filtering device.
• Line Power Conditioners - Power or Line Conditioners regulate, filter, and suppress noise in AC power for sensitive computer and other solid state equipment.
• DC Power Supplies - Conversion of one form of electrical power to another desired form and voltage. This typically involves converting 120 or 240 volt AC supplied by a utility company to a well-regulated lower voltage DC for electronic devices.
• Rotary Phase Converters - Rotary Phase Converters are commonly used in home or small commercial or industrial settings. Rotary phase converters convert single-phase power into three-phase power. This is a very cost-effective way to power three-phase electric motors and other three phase equipment.
• Frequency Converters - A Frequency Changer or Frequency Converter is an electronic device that converts alternating current (AC) of one frequency to alternating current of another frequency.
• Voltage Converters - A Voltage Converter changes the voltage of an electrical power source and is usually combined with other components to create a power supply.
• Magnetic Motor Starters - Magnetic Motor Starters are essentially heavy duty relays mounted in boxes, often equipped with heater/thermal overloads matched to the motor they start.
• Motor Starting Auto Transformers - An Auto Transformer starter uses an auto transformer to reduce the voltage applied to a motor during start. The auto transformer may have a number of output taps and be set-up to provide a single stage starter, or a multistage starter.

For an additional resource the Best of Industry Web Directory : Electrical Power Transformer Directory section is quite useful.