Distribution Transformer

HEXTA ENERGY SAVING TECHNOLOGY

Construction Feature:


Oval Shape Core

Core design is an important factor of any transformer’s design. The geometric core arrangement and the materials chosen directly determine its efficiency such as the losses and noise levels. Different from traditional core design, HEXTA new generation transformer selects oval-shape for its core and winding design, which makes it a truly double oval shape aka Oval2Oval transformer.

In term of construction materials, HEXTA uses grain oriented transformer sheet steel insulated on both sides. Cut by the most modern, fully automated core cutting machinery and then assembled into limb and yoke sets, HEXTA transformers offer high dimensional accuracy, excellent space factor, and low loss values. Using step-lap technology, HEXTA can further reduce the no-load currents and improve the drawbacks associated with reactive power compensation.

Oval Shape Windings

HEXTA’s new generation windings are made of two components, conductor material and the insulation material. The conductors used are from high-grade electrolytic copper or aluminum (foil). They are insulated with pure cellulose or double enamel with the benefit of automatic adjustment for high voltage ampere-turn asymmetry through internal current distribution.

Through HEXTA’s new generation winding process, the coil is cured into an oven in oval shape to ensure the creation of an  extremely compact solid winding.

The special designed Oval2Oval Transformer as part of HEXTA new generation technology is a result of combining both traditional square winding and round winding to offer its customer the reduction of core loss and excellent short-circuit withstand capability.

However, these benefits do not come easy and require specially adapted design and experienced engineering. The requirement of manufacture expertise is high as well. In addition, HEXTA’s HV winding adopts entanglement or inner screened continuous type with phase insulation structure to ensure insulating strength; MV/LV windings adopt high strength conductor, reinforced cooling to reduce the temperature rise and further enhance capability of short circuit withstand. To ensure the best performance, the neutral point of LV windings in HEXTA transformer are brought up to the tanks cover. From the size perspective, it is also more compact than traditional transformer.

Off Load Tap Changer

HEXTA’s tappings of the HV winding are connected to the off-circuit tap changer located horizontally between the yoke and the tank cover. The handle is set on the cover and can only be operated when transformer is de-energized. This safety feature design prevents setting the off circuit tap changer to intermediate positions, which also can be padlocked during normal transformer operation.

Environment Compliant Insulating Liquids
HEXTA’s mineral oil – both inhibited and uninhibited type – its electrical and chemical characteristics is P.C.B and P.C.T. free. It is biodegradable and non-hazardous, safe for use even in the most ecologicallysensitive areas.

HEXTA also provides and promotes its own solution. On special request other fluids are available.High Endurance Tank
HEXTA’s next generation tanks are primarily constructed with cooling fins. Under special requirement, HEXTA also carries panel radiator types upon customer’s request.

HEXTA’s next generation tank walls are made of corrugated cooling surfaces. The bottom plate, side and frames are of welded construction. The welds are well tested for oil tightness. On the tank cover are fitted with all protection device flanges,bushings, tap switch drive and lifting lugs are fitted with the cover bolted to the tank frame.

The under-base channel is welded to the base plate and the rollers are suitable for either longitudinal or transverse movements.

Within HEXTA, 3-phase transformers are delivered with flat base as standard, but optionally HEXTA can provide underbase as
standard, equipped with underbase channel beams where wheels are a requirement.

All complete HEXTA tank is tested and approved according to Indonesian standard. To ensure the quality, HEXTA conducted special type lifecycle tests of more than 10.000 cycles to simulate the 20 years of operation period with positive results.

Sophisticate Painting & Surface Treatment

Under each HEXTA new generation transformer, all metal parts are carefully sand blasted and processed through series of steps of protective measures to ensure the endurance of each part. The final paint coating is powder coat by PT Hup Siong Indonesia, a well known Malaysian metal works and powder coating company.

Alternatively, HEXTA also supply hot dip galvanized transformers for uses in heavy corrosion areas, all units are painted with several choices of colors available on request.

Detailed painting procedures for different environmental conditions are also available.