Voltage Transformers, GE, Winding Assembly, Electrical Power, Dry Type transformer,

TRANSMISSIN AND DISTRIBUTION - Dry Type Transformers

Medium Voltage Transformers
We are the authorized representative of GE Medium Voltage Transformers.

"Need A Medium Voltage Transformer With Guaranteed Reliable Quality, Fast Delivery, And Guaranteed Results?"

We have answer to your needs with our New Copper Wound Medium Voltage Transformers from GE Shanghai

WaveCast 724 cast coil transformers from GE Shanghai are characterized by proven technology, application flexibility, lower installation cost, operating efficiency and environmental acceptability. Advanced design of the winding assembly establishes superior performance to meet today's exacting needs. Indoors or out, they are designed for use in the most demanding and diverse environments and in all applications requiring reliable electrical power.

Typical applications of cast coil transformers include:

	Steel mills
	Industrial critical power solutions
	Pulp & paper mills
	Chemical plants
	Cement & mining operations
	Automotive industry
	High rise building & water-side installations

Cast coil transformers offer several advantages over alternative transformer technologies.

Mechanical strength

Because of the strong protection provided by the vacuum cast epoxy encapsulated coils, Wavecast 724 transformers are stronger than either liquid or ventilated dry-type transformers. Short circuit tests have proven this strength well beyond IEC requirements. GE Shanghai designs and manufactures its cast coils to be among the strongest in the industry. The strength of WaveCast 724 transformers makes them ideal for such applications as impact loading, mobile machinery and transit systems.

Impervious to adverse atmospheric conditions

Unlike ventilated dry-type transformers and in a manner similar to liquid filled transformers, GE Shanghai Cast Coil transformers are optimal for application in low quality environments. The epoxy casting is extremely inert and renders the windings impervious to moisture, dirt and most corrosive elements .

Suitability for simple indoor installations:

Unlike the case with liquid filled transformers, indoor installations do not require an automatic fire extinguishing system or fire vault, oil checking or replacing, or a liquid confinement area.

VACUUM CAST WINDINGS

TOUGH EPOXY PROVIDES THE STRENGTH.

WaveCast 724 vacuum cast windings are highly engineered utilizing specific expertise in electrical, material, thermal and mechanical engineering. The close monitoring of measuring, mixing, heating and vacuum casting materials into the windings is equally critical.

Cast coils are solid vacuum cast with epoxy resin compound.

The epoxy is applied under vacuum to hermetically seal the windings in a highly durable epoxy, quartz filler is included. The epoxy mixture is carefully designed to provide maximum strength and environmental protection and yet minimize the temperature differential through the coil thickness. Process control ensures that the coils are void-free and prevents partial discharges within the resin material or cracking of the epoxy over a wide range of ambient and operating temperatures.

ADVANTAGE OF SOLID VACUUM CAST DESIGN


	Cast Coils seal out
	Harmful Fumes
	Air and Moisture
	Achieves a maximum degree of resin impregnation during the casting process.
	Dielectric strength (Partial discharge free)
	Mechanical strength (Short circuit capability exceeds IEC)
	Insulation system ( 155°C insulation system)
	Thermal strength ( Withstands fluctuating operating temperatures ranging from 155°C to 30°C)

WINDING ASSEMBLY

HIGH AND LOW VOLTAGE WINDINGS ARE VACUUM CAST IN METAL MOLDS AS SEPARATE CONCENTRIC CYLINDERS.

High voltage windings are wound using strip foil technology. Multiple layers of Mylar-A provide turn insulation. Individual coil sections are wound directly onto the HV winding form and then connected in series by welding.

Low voltage windings use sheet conductor construction. A fiberglass mesh provides support for the inside of the winding. Full-width sheet conductor and DMD layer insulation is wound onto the cylinder. Start and finish lead bars are TIG welded to the sheet conductor. Low voltage windings are also vacuum cast in a metal mold using the same technique as the high voltage windings.

Why strip foil windings?


	High power frequency and impulse-voltage strength
	High short-circuit strength
	Low hotspot temperature rise differential

CORES

CONSTRUCTION ENSURES OPTIMAL PERFORMANCE.

Transformer cores utilize mitered step-lap technology to optimize performance and minimize sound levels. Cores are constructed of non-aging, high permeability, grain-oriented silicon steel laminations without punched holes offering high magnetic permeability.

Core laminations are free of burrs and stacked without gaps, resulting in the lowest possible losses from magnetic hysteresis and eddy currents.
Magnetic flux densities are kept well below saturation point,surfaces of the core, clamps and tie rods are all treated against corrosion.

ENCLOSURES

WITHSTANDS THE HARSHEST INDOOR AND OUTDOOR ENVIRONMENTS.

They are enclosures suitable for lifting, jacking, rolling or skidding. Core and coil technologies have been enhanced to combat caustic and humid environments also contains additional protection against harsh outdoor or indoor environments.

STANDARDS AND CERTIFICATIONS

	IEC 726
	GB1094
	GB6450
	UL Pending
	ISO 9001

TESTING

Tests are performed in accordance with IEC-726/GB6450. Routine tests as outlined in IEC-726/GB6450 are performed on all transformers and include:


1.	Resistance measurement of all windings on rated tap
2.	Ratio (turns ratio) tests on the rated voltage connections
3.	Polarity and phase relation test
4.	No-load losses and excitation current test
5.	Impedance voltage and load losses at rated current
6.	Applied potential test
7.	Induced potential test
8.	Partial discharge
9.	Insulation resistance

OPTIONAL TESTS

Optional tests are performed on each unit according to the customer specification, otherwise verified with testing data from a similar unit with similar design. These optional tests include:


1.	Impulse
2.	Temperature rise
3.	Audible sound level