Suppliers, Distributors, and Exporters of TEFC Squirrel cage induction HV Motors

TEFC Squirrel cage induction HV Motors comply with the requirements of IEC 34-1, the relevant parts of BS4999 and BS5000, IS:325 & other relevant Indian standards. They are designed for continuous duty corresponding to Duty Type S1 of IEC 34-1 and BS4999, part 101 section 3, with a temperature rise by resistance not exceeding 80K in a maximum ambient temperature of 40°C.

The standard rated outputs are taken from the R40 series of preferred numbers in accordance with the requirements of clause 7 of BS4999 Part 101 and Part 1 of IEC 34-1. For enquiries with intermediate ratings the next highest preferred rating will be offered and performance data will be quoted accordingly

100% ROUTINE TEST

Quality is emphasized at each step as a motor proceeds through each stage of design, assembly and testing. Each motor is given a routine test as required by Reference - IS 325 / IEC 60034-1 to determine that it is free from electrical or mechanical defects.

Additional special tests beyond the routine test are available on request. Tests may be witnessed if required.

Dimensions

Dimensions are in accordance with BS4999 Part 141, IEC 72 and 72A.

Degree of Protection by Enclosure

All motors in the TEFC High Voltage Cage Induction HV Motors range have a degree of protection IP55 as standard, conforming to the requirements of IEC 34-5, BS4999 Part 105 & IS:4691.

This is defined as dust protected and suitable for operation in heavy seas (ships deck duty).

Method of Cooling

The standard of cooling form as defined within BS4999 Part 106, is IC 0141-totally enclosed fan cooled. (The equivalent IEC 34-6 nomenclature for this enclosure type is IC411).

Forced ventilation (IC 416) is also available, suitable for constant torque V.F.D, (690 V) application.

Mounting

Mounting designations are in accordance with IEC 34-7 Code 11 and BS4999 Part 107. The standard mounting arrangements available on all frame sizes are.

• IM1001 – Horizontal foot.
• IM3011 – Vertical flange
• IM2001 – Horizontal foot and flange

Supply

Standard ratings are based on supply voltages of 3300 or 6600 volts on a 50 Hz supply frequency and 2300 or 4160 volts on a 60 Hz supply frequency. Other voltages and frequency combinations one available on request.

Insulation

The winding insulation system is class F in accordance with IEC 85 and BS2757. More detailed information on insulation & Vacuum Pressure and Impregnation (VPI) system/ processes are available on request in a separate publication entitled Resivac – The VPI insulation system.

Stator Frame and Endshields

Stator Frames and endshelds are produced from high grade cast iron with deep external cooling ribs. Spigotted Endshields are fitted to the frame and incorporate the bearing housings.

Motor feet, terminal facings and two lifting eyebolt bosses are cast integral with the frame. Horizontal frames also have jacking screw provision and pilot dowel holes as standard.

The TEFC High Voltage Cage Induction HV Motors range of machines have permanently fixed air gaps achieved by close tolerance machining of all components.

Bearings

The standard bearing arrangement has C3 internal clearance metric rolling element bearings that are mounted directly into the bore of the endshield. Premium quality lithium based grease containing oxidation and corrosion inhibitors is used and pressure grease relief facilities are a standard feature. All rolling element bearings have long Relubrication intervals and an L10 bearing life of greater than 40,000 hours.

Self contained or flow lubricated plain bearings can also be fitted if required. Flow lubricated plain bearings are fitted with inlet and outlet flanged stub pipes, for connection to an oil supply provided by others.

On vertically mounted motors the rotor weight is supported by the top bearing which would either be of the deep groove ball or duplex type depending on the axial loading to be accommodated.

All bearings used are of the highest quality produced by internationally recognized manufacturers ensuring spare parts are readily available. An insulated bearing arrangement can also be provided on request.

Motor bearings have been selected on the basis that the machines are directly coupled, without external thrust being imposed by the driven equipment. If this is not the case then details should be provided to allow appropriate design consideration.

Stator & Rotor Cores

Machines have a laminated & insulated sheet steel stator core assembly, which is built on a mandrel & welded under compression, before fitting into the stator frame.

The rotor core made of laminated steel sheet is an interference fit on the shaft. The core is compressed between fabricated steel end plates and the assembly is then securely locked into position with steel key ring.

Stator Coils

Stator coils are formed from annealed copper strips, insulated with mica. Loops of the appropriate number of turns are formed, the coil strait portion is bonded & the loop is then pulled to shape. The coil is insulated with layers of mica tapes.

Coil Connections & Bracing

The coils are inserted in the slots, and firmly wedged in position with epoxy glass or magnetic slot wedges. End windings are securely braced to prevent movement during service.

The winding is high voltage tested at both mains and high frequency immediately after the coils are inserted and wedged, and again after connecting. On completion of winding phase resistances and impedances are checked for balance and conformance with design.

Impregnation

TEFC High Voltage Cage Induction HV Motors stators are Vacuum Pressure Impregnated (VPI) with an epoxy resin.

The VPI system utilities materials with a minimum resin content at the winding stage, and places greater emphasis on the final impregnation treatment.

This not only extracts all air from the winding, but also forces the resin, under pressure, into the interstices of the coils until they are totally filled. All coil packings retain a high proportion of resin and the connections become one consolidated ring after rotate curing in time and temperature controlled ovens.

After impregnation the windings are subjected to the voltage tests specified in BS4999 Part 101, section 9. All machines one subject to loss tangent tests.

Rotor Bars

All motors have copper or copper alloy rotor cages. Tight fitting rotor bars are butt brazed to copper or copper alloy endrings. All rotors are dynamically balanced to more stringent levels than those specified in ISO2372.

Overall motor vibration severity does not exceed the limits specified in IS:12075.

Shafts

Shafts are manufactured from carbon manganese steel of grade 150M28 to BS970 or equivalent. Standard motors have a single plain parallel shaft extension with a single keyway and motors are balanced with a half key fitted.

The shaft extension is drilled and tapped in accordance with BS4999 Part 141.

Fans & Cowls

TEFC High Voltage Cage Induction HV Motors 2 motors are fitted with unidirectional law noise level fans manufactured from galvanized steel. Fan cowls are also manufactured from steel.

Also for some applications one additional internal fan is used in place of wafter to get more thermal efficiency.

Terminations

Unless otherwise specified, motors are supplied with a single fabricated steel, air insulated terminal box (for 3.3 kv) containing three mains terminals suitable for direct-on-line starting.

The box is mounted adaptor and is supplied with a blank gland plate. Special glands can be supplied to order. Phase segregated terminal box is provided for 6.6 kv Motors and for 3.3 kv Motors on request. A wide range of alternative boxes are available.

When specified, access to the winding neutral point can be provided by removal of a steel cover or within a separate terminal box. The prospective system fault level should be advised to enable selection of the most suitable terminal arrangement.

Auxiliaries

TEFC High Voltage Cage Induction HV Motor allows the flexibility of fitting a wide variety of instrumentation and auxiliaries including winding and bearing temperature sensing elements, vibration transducers, anti-condensation heaters and silencing elements.

Contact us for more information on Torque motors or to discuss your requirements. Enquiries are solicited for India, UAE and Africa on following Email id web@aakashpower.com