VOLTAGE TRANSFORMER 1250 KVA

DISTRIBUTION TRANSFORMER

PRODUCT RANGE

Power& Distribution Transformers 63 KVA in 11&33 KV voltage class.

STANDARDS

Power Transformer are designed and tested as per IS: 2026, BS-171, iec-76 & IEC-726.

VECTOR GROUP

Transformer will be connected as per vector group reference Dyn11. Other vector groups can be offered as per specifie requirements.

TERMINAL ARRANGEMENT

H. V. – Bare Bushings or cable box, L.V. – Bare Bushings or Cable Box. Disconnecting chambers can also be provided on both HV and LV Cable boxes.

TEMPERATURE RISE

Transformers are designed for a maximum temperature rise of 50/55 degree c of oil /winding. Lower temperature rise can be offered on request.

CORE

The core is constructed from low loss, cold rolled, grain oriented. Annealed lamination of electrical sheet steel conforming to the latest international standards. Special frame is built in –house for clamping the core to reduce the magnetic noise as well as making the whole structure rigid and robust.

STANDARD FITTINGS

1-      Monogram plate, Rating and diagram plate, Earthing terminals – 2 nos, Cover lifting hooks Lifting lugs,

2-      Jacking Lugs (500 KVA & above), Prismatic glass oil level indicator Drain-cum bottom filter valve with plug,

3-      Oil filling hole with plug on conservator, Oil conservator with drain plug Air release plug

4-      Silicagel air breather, Bi-directional flat rollers HV terminals-outdoor bushings

5-      LV additional neutral-1 No. outdoor bushing without socket(for star connected enclosed LV terminals)

6-      Pressed sheet radiators (tank mounted up to 800 KVA and detachable thereafter) Filter valve with plug

7-      Thermometer pocket Oil temperature Indicator (stem type)

8-      Externally operated off circuit tap changing switch , Pressure relief valve without electrical contacts

9-      Sampling valve (for 2000 kva&above Trf.only)

ACCESSORIES (OPTIONAL)

1-LV and HV cable boxes

2-Winding temperature indicator

3-Buchholz relay

 4-Magnetic oil level gauge

5-Marshalling box

6-Disconnecting chamber

             WINDINGS

Coils area wound with electrolytic high conductivity paper covered or synthetic enameled copper conductors. Cooling ducts area provided to keep the hot spot temperature as low as possible. Coils area dried in electric ovens. Rigid connection support and coil clamping is provided to ensure high short circuit strength.

INSULATION

Precompressed bord PARMALI bord and JAPANEESE insulation paper of best quality is used.

TAPPING

A. OFF CIRCUIT TAP CHANGING SWITCH

Toppings from +5% to -5% in step of 2.5% for HV variation or as per customer’s requirement.

                                                                           B. ON LOAD TAP CHANGER

Tapping range as per specific requirements can be offered. OLTC for remote/auto/parallel operation can also be offered.

                                                             OIL

Oil is tested for resistivity, dielectric and acidic characteristic conforming to IEC-296/IS-335 before topping up, oil is filtered thoroughly

                                                        TANKS

The tanks are made of M.S. Steel plates/sheets with adequate bracing & stiffeners. Tanks are pressure tested to withstand any type of inside or outside pressure. All the external surfaces are given a primary coat of zinc chromate, red oxide and two finishing coat of grey paint. The inner surfaces are given a coat of heat and oil resisting paint.

PAINTING

All the external surfaces are given a primary coat of red oxide and two finishing coats of paint. Paints and enamel varnish used confirm to IS: 104 & 2932.

TERMINAL ARRANGEMENT & BUSHING

Following arrangements are provided: (a) H.V.-Bare or cable box bushings (b) L.V.-Bare or cable box bushings, disconnecting chambers can also be provided on both HV& LV cable boxes. Bushing conforms to IS: 3347, 2099, HV/LV bushing terminals of brass /copper conformers to IS: 3347 Section-II metal part.

GASKETS & JOINTS

All gaskets used for making oil tight joints to be with cork as base banded by oil resisting synthetic material or rubber. Neoprene rubber is used for oil tight joint for HV& LV terminals. The gaskets conform to IS: 4253, part II-1980 (Reaffirmed 1999) NC 777, RC 70C.

QUALITY CONTROL& ROUTINE TESTS

All Power Transformers undergo rigorous quality control checks and area routine test as per IS in our fully equipped laboratory. Any specific test required by the customer can also be arranged.

Special purpose variable voltage supplies (0-11000 V, 2000 KVA)