Cage Motors

VERTICAL HOLLOW SHAFT ( VHS ) MOTORS

These motors find special application in driving Vertical Turbine, Propeller, Mixed and Non-clog Pumps

SPECIFICATIONS

Hydro Electicals Motors are continuously rated (S1 duty) as per IS:325 and are suitable to operate on 3-phase 415 V± 10% , 50 Hz ± % electric supply. Combined voltage and frequency variation on load is ± 10%. The performance generally conforms to IS : 325. The motors are available in ratings upto 45 KW/60 HP, 1500 RPM & 18.5 KW/25 HP, 3000 RPM, in frame size upto 200.

ENCLOSURE AND MOUNTING

Motors are in drip-proof enclosure having degree of protection IP-22 as per 4691. Top cover dome and metallic screen are specially designed to give protection against dripping liquids and falling objects. It also prevents any possibility of accidental touch to moving parts by the operators. Mounting flange dimensions of these motors are in accordance with IS-2254.

STATOR / ROTOR STACKS

Stator and rotor stacks are made of low-loss silicon steel laminated stampings to minimise iron lossed.

The Stator stack is held in position by stacking ribs in motor body to ensure uniform air-gap and to minimise

Rotor stampings are directly stacked on precisely machined carbon steel shaft. The rotors are aluminium die-cast. All rotors are finished to close tolerances and dynamically balanced on highly accurate electronic balancing machine.

WINDING AND INSULATION

Stator winding is of Polyester Super Enameled copper wires conforming to IS.13730, Part-Ill. The overhangs of the windings are well shaped and rigidly braced to withstand high stresses developed during starting of the motor. Class 'F insulating materials with temperature rise limited to 'B' are used as insulation to provided electrical, thermal and mechanical strength to the windings. The temperature rise is limited to 75°C over the ambient temperature of 45°C.

BEARINGS

Carefully selected angular contact. Heavy duty bearings are located at the top to take the thrust load and deep groove b bearing is used at the bottom of the motor. The floating arrangement at the bottom bearing ensures safety of these bearings against possible damage due to imposition of thrust load and axial expansion of shaft. Ball bearings are greased with lithium base gr-ease grade-3 having a drop point of more than 160°C. Well designed lubrication arrangement is provided for both top and bottom bearings.

VENTILATION

The optimum cooling is effected by guided air flow generated by rotor fins/fan. The cooled air is taken in from the top and the hot air is expelled out from the bottom. The air openings are well protected by properlly sized screen.

COUPLING

An easily accessible coupling located at the top of the motor facilitates coupling of pump and motor as well as permits vertical adjustment of the impellers in the pump through head shaft.

TERMINALS AND TERMINAL BOX

Six terminals made from extruded brass/copper rod and having adequate current carrying capacity are provided for either star-delta or auto transformer starting. Delta links are provided if required for direct-on-line starting. Terminal Box has ample space if required for easy terminal connections. Cable entry can be arranged from any direction in steps of 90°.

EARTHING

2 Nos. earthing bolts are provided for earthing connection at diametrically opposite connection.

TEST

All the motors are tested during manufacturing and before despatch, in accordance with IS:325. In case motors are required for wider voltage variations for operating at different voltage, the same can be offered on request.