Ames impex eleeectrical pvt ltd Mehsana, Mahesana, Gujarat

he unitized substation comprises the following main components. Vacuum Circuit Breaker panel in outdoor enclosure up to 11KV, 33KV complete with CT, PT, Relay & Instrument chamber. The outdoor panel is directly coupled with HT Flange of the transformer with copper busbars. The incoming of the HT Panel is provided either with Plug Socket or Cable box. Alternatively Load Break Switch or a Ring Main Unit can also be coupled with the HT bushing of the transformer. Outdoor type Cast Resin Dry type Transformer up to 2000KVA 11KV-6.6KV-33KV415V,DYn11, and with off-circuit tap links and standard fittings as per ISIEC standards. The transformer has HT Flange with bushings to be coupled directly with the outgoing of the HT Panel and LT flange with the incoming of LT Panel. The transformer can be either Dry type Resin Cast or Dry type with Nomex insulation. With Dry type transformer the total unit is housed in a single outdoor type enclosure in place of three separate enclosures. LT Panel is outdoor type comprising of one or more air circuit breaker or MCCB either in single or board formation suitable for a System Voltage of 415V,3-Phase 50 CS. Incoming of LT Panel is directly coupled with the LT flange of the transformer. The output is either Cable box or Plug & Socket arrangement for feeding power to LT equipment.

Unitized Transportable Substation is used for feeding power from high voltage to low voltage in open cast mines, construction sites, metro cities, etc. The substation is compact in size, suitable for frequent shifting and for use in outdoor locations. The substation is installed and mounted on skid frame or wheels or channels and is provided with lifting hooks. The unitized substation comprises the following main components. Vacuum Circuit Breaker panel in outdoor enclosure up to 11KV, 33KV complete with CT, PT, Relay & Instrument chamber. The outdoor panel is directly coupled with HT Flange of the transformer with copper busbars. The incoming of the HT Panel is provided either with Plug Socket or Cable box. Alternatively Load Break Switch or a Ring Main Unit can also be coupled with the HT bushing of the transformer. Outdoor type Cast Resin / Dry type Transformer up to 2000KVA 11KV-6.6KV-33KV/415V,DYn11, and with off-circuit tap links and standard fittings as per IS/IEC standards. The transformer has HT Flange with bushings to be coupled directly with the outgoing of the HT Panel and LT flange with the incoming of LT Panel. The transformer can be either Dry type Resin Cast or Dry type with Nomex insulation. With Dry type transformer the total unit is housed in a single outdoor type enclosure in place of three separate enclosures. LT Panel is outdoor type comprising of one or more air circuit breaker or MCCB either in single or board formation suitable for a System Voltage of 415V,3-Phase 50 C/S. Incoming of LT Panel is directly coupled with the LT flange of the transformer. The output is either Cable box or Plug & Socket arrangement for feeding power to LT equipment.

It is an important device of reactive compensation equipment of power system and series with shunt capacitor can limit the enlargement of high harmonic in the electric net and surge current when closing to ensure the safe operation of capacitor.

TECHNICAL FEATURES : Manufacturing Standards IS-2026 / IEC-76 Core The Core is build up from interleaved low loss cold rolled, grain oriented Silicon Steel laminations. Individual stampings are coated on both sides with an insulating material, which is both oil and temperature resistant. The core limbs are securely bound with heavy duty webbed cotton taps and the yokes are firmly clamped between steel channels, all cores have mitered joints. Top and bottom clamps are secured to each other by means of tie rods which serve the dual purpose of securing the windings in place and of transferring the load from the bottom to the top clamps when the core and windings are lifted. This prevents tensile stresses being set up in the core legs which could adversely affect the iron losses. Windings Transformer windings are designed to meet three fundamental requirements such as mechanical, thermal and electrical. They are cylindrical in shape and are assembled concentrically. The low-tension windings are of the helical type, single or multilayer, using flat copper strips, depending upon the size and current rating of the transformer. The high-tension windings consist of paper covered conductors (round and strips) depending upon the current rating of the transformer. For higher capacity continuous disc windings are used. The windings are rigidly supported by pressboard washers and spacers. Interlayer cooling ducts are provided to ensure that the temperature gradient between windings and oil and hence the hot spot temperature is minimized and higher life expectancy is achieved. Insulation between layers and turns is based upon the impulse test level of the voltage class of the windings as specified in IS 2026.Completed Core coil assemblies are dried prior to impregnation with transformer oil. Winding Connections Tappings and leads are run in multi paper covered flexible conductors in press board half tubes, the phase leads being separated from the tapping leads by adequate barriers. These tubes are rigidly based to ensure that clearances between leads and tank sidewall are maintained when the transformer is fixed in position. Low voltage leads being of larger cross section are sufficiently robust, so supports are provided wherever necessary. Insulation and Impregnation The principal components of insulation are pre-fabricated from pressboard sheet. All items subjected to compression in services are preshrunk and the slight recovery in dimensions after preshrink age is compensated for windings during final drying of the completed transformer. The oil used for impregnation complies with IS 335 and every consignment received at works is tested before entry is permitted into the storage tanks. Short Circuit Strength In order to prevent deformation when subject to short circuit force, solid blocks and insulation, backed by substantial supporting frames, are utilized. The axial end thrust under fault condition is minimized by ensuring that design dimensions are closely adhered during manufacturing procedure. Transformers are designed and constructed in such a way that they are capable of withstanding the effect of short circuit testing. Our transformers have been type tested at CPRI and ERDA. Tapings For the range of transformer covered in this Catalogue, tapings are provided on the H. T. Windings at ±5% in steps of ±2.5%. Other tapping ranges can be supplied on request. Tap selection is effected by means of an off-circuit tapping switch operated by an external handle. Leads for Tapings are brought away from the coils by the means of paper insulated conductors. They are arranged in such a manner that the ampere-turn balance is maintained throughout the tapping range. ON-LOAD TAP CHANGRES are also provided depending upon customer requirement. Terminations All bushings are of high quality porcelain or Epoxy complying as per IS 2099

Manufacturing Standards The transformers are built in accordance with IS 11171 and IEC 726 standards. Core The core is built of cold rolled oriented grain steel with low specific losses, insulated on both sides by a thin inorganic coating (Carlyte). The sheets composing the core are cut at 45 degrees C. Uniform pressing, stiffness and solidity of the columns assure a low noise level. High Voltage Windings The high voltage windings are made of electrolytic COPPER SUPER ENAMELLED F/H CLASS conductors (wire or foil strip depending upon power and voltage requirements). It is possible to produce Aluminium windings. The windings are Casted under vacuum in class F/H epoxy resin depending on requirement. The accuracy of execution of these processes allows the obtainment of windings free from partial discharges. Low Voltage Windings The low voltage windings are made of strip or foil (copper or aluminium conductor depending upon power and voltage requirements). Class F/H insulating material is used. Rating and diagram plate Earthing terminal Skid under base or truck with bidirectional wheels Primary Terminal Secondary terminal lifting lugs Enclosure with IP 21, 23 or other protection class Temperature monitoring unit with display