1. STANDARD
The Transformer are manufactured in accordance with IEC-76, BS-171, NEMA-TR1, SPLN, ASEAN Standards, and individual customer requirements.

2. CORE
The cores use high quality cold rolled grain-oriened silicon steel sheet. They provide low iron loss, low noise, compact size, and the best performance for high efficiency transformer. :
Type of Core : a. Strip- Wound Core : For Application in single-phase or three-phase compact size transformers with low noise and exelent magnetic circuit characteristics. b. Step-Lap Core : It is suitable for application in single-phase or three-phase, core- type or shlell-type compact size trransformers. It has excellent magnetic circuits which reduce iron loss considerably and greatly increase the mecanical strength of transformer. C. Stacking Core : The mitred core, joined by 45-degree cut silicon steel sheets, has exellent mechanical strength, and is for application in three-phase, high capacity transformres. It can have best performance on low iron loss by using high quality silicon steel sheets.

3. WINDINGS
A. Material : We use high quality products :
1. Round Enamelled Magnet Wire
2. Paper-Wrapped Rectangular Cooper Wire
The wires, ribbid with thermally-upgraded insulating paper, are applied in oil-immersed transsformers.
3. Copper/Aluminium strip; The high conductivity copper or aluminiumfoil is applied in low voltage windings. The foils must be processed through an edge-modifier to get rid of burrs and to have the round edges.

B. Winding Structure : Basic design are as follows:HV-LV(Core Type), LV-HV-LV(shell-type). By using a copper/Aluminium strip, rectacular cooper wires, the windings have a compact size exellent heat transmission, low load lose, high lightening, impulse resistivity, and outstanding anti-short-circuit strength.

4. INSULATION :
Our oil-immersed transformers use press board, thermally upgraded insulating kraft paper, and insulting oil(mineral, silicon, or high fire-point oil, etc). We normally apply "Shell" Diala B grade as our standard transformer oil : specified by PLN - PT. (Persero) Listrik Negara.

5. BUSHINGS :
A. HV Bushing : High quality porcelain bushings are used on the high voltage's terminals. Optional bushing wells and plug-in bushing are upon request, allowing high voltage cable to be inserted directly, and show no live parts outside.

B.LV Bushing : High quality porcelain LV bushings can be equiped with clamp type, stud bolt type, or spade type terminals. The above mentioned LV terminals are able to be connected with switch gears by cables or bus-bars.

6. TANK :
A. All tanks are assembled by cold rolled and hot rolled stell plates throug welding. They are equipped with radiators or corrugated steel sheets in accordance with capacity of transformer. Meanwhile, reinforced structure aand pressure relief valves encahence the strength of tanks to face a harsh operation environment.

B. The tank must go through degreasing, acid cleaning, phosphide film, oxide primer, and polyurethane process etc. to guarantee its functioning in the worst operation environment.