Power down-step three-phase double winding oil transformers for indoor and outdoor installation power rating from 400 to 1600 kVA are intended:

• (ТМБ) for drilling rig electric equipment power (supply);
• (ТМЭ) for excavator electric equipment power (supply) which are set on its platform.

Specification

ТМБ and ТМЭ power transformers are manufactured with primary winding (HV) voltage rating up to 10 kV and secondary winding (LV) voltage rating up to 0.4 kV.

The transformers are equipped with HV tap changers, which allow voltage regulation on LV and HV side by ±2 х 2.5 % steps while the transformer is switched off the system.

Operating Condition

Altitude above sea level – up to 1000 m.

Temperature of ambient air:

• for temporary climate: from –45С to +40С (У modification);
• for cold climate: from –60С to +40С (ХЛ modification);
• for tropical climate: from –10С to +50С (T modification).

Relative air humidity:

• not more than 80% for У modification;
• not more than 95% for ХЛ and T modifications.

The transformer operation is possible under vibrating and shaking conditions which are caused by the transformer operating.

The transformer operation is possible under recurrent cleaning from dust conditions within 400 mg/m³ dust level.

The transformers are not to operate in flammable and corrosive medium.

Transformers construction

The transformers tanks are of rectangular form. There are closed in box with packings inputs on the narrow opposite tank walls.

The inputs are dismountable; the insulators are bushing, made of porcelain which are not intended to operate in polluted with active gas and current-conducting dust medium.

The active part consists of a magnetic core, which is made of cold-rolled electrotechnical steel, windings and a HV tap changer.

The windings of the transformer are made of aluminium and copper (for T modification).

The oil dilator provides the availability of oil at all modes of transformer operation and temperature oscillations of the outside ambient. For oil level monitoring an oil level indicator is fastened onto the oil dilator butt. The oil level indicator has three control marks, which correspond to the oil level in non-functioning transformer at different temperatures:

• –45С, +15С, +40С – У modification;
• –60С, +15С, +40С – ХЛ modification;
• –10С, +20ОС, +50С – T modification.

The power transformers rating 1000, 1600 kVA are equipped with a gas relay and safety (exhaust) pipe which is activated at more than 0.5 atm internal pressure.

For short distance portaging and fastening onto an excavator platform the transformers have a sled with holes.