Squirrel Cage Induction Motors

 Havells is manufacturing three phase LV Motors at Neemrana (Rajasthan). The motors are manufactured in technical collaboration with Lafert (one of the largest motor manufacturer in Europe) who are now the owners of AEG Electric Motors.

All the motors are being manufactured conforming to the relevant Indian and international Standards and are robust in electrical and mechanical design to, cater under severe environmental conditions for every application such as 

• Pumps
• Conveyors
• Fans
• Compressors
• Cranes
• Blowers
• Hoists
• Vibrators

 

The plant has a capacity to manufacture over 250000 nos. energy efficient motors per year ranging from 0.12HP to 300HP extendible to 500HP in near future. The complete range of motors from frame 56~315 are manufactured in-house and the plant and machinery has been procured from AEG Electric Motors.

The motor manufacturing plant comprises of :

• Fully automatic winding lines
• Automatic impregnation plant
• Ultra-Violet impregnation plant
• Fully automated temperature controlled paint stations
• Fully equipped Mechanical Test Lab
• Modern Type Test Plant having 9 test beds with Power Analyzers

Crane Duty Motors

Crane Duty Motors have been suitably designed for arduous applications for short and intermittent duties involving starts, stops and reversals.

Product Range

Frame : 71- 160

kW/Hp : 0.37 – 15 / 0.5 - 20

Pole : 4-8 Pole

Mounting : Foot, Flange, Face and combination

 

CE Marking

All motors have CE Marking.

 

Operating Conditions

The standard operating conditions for the crane duty motors are:

Voltage :  415 ± 10% Volts

Frequency :  50 ± 5 % Hz

Combined :  ± 10 %

Ambient Temperature  :  450 C

Altitude :  Upto 1000 m above mean sea level

 

Standards

The motors conform to the following standards

IS: 325  Three Phase Induction Motors-Specification

IS: 1231 Dimensions of Three Phase Foot Mounted Induction Motors

IS: 2223 Dimensions of Flange Mounted Induction Motors

IS: 4722 Rotating Electrical Machines-Specification

IS: 4691 Degree of Protection For Rotating Electrical Machines

IS: 6362 Designation of Methods of Cooling of Rotating Electrical Machines

Intermittent Duty Application

The motors are designed for intermittent duty operations and different starts/stops per hour as shown in the rating charts. The frame selections are based considering load GD2 values referred to motor shaft are less than or equal to motor GD2 values. Various intermittent duty types are explained below.

 

Short Time Duty - S2 Duty

The motor operates at constant load for a given duration which is less than that required to reach thermal equilibrium and is followed by a rest or de-energized period such that the motor cools down to close to ambient temperature.

 

Mechanical Design

Construction

Crane Duty Motors are available in Aluminum/ Cast Iron frames. Frames 80 & 90 shall also be available in cast iron on request. For higher frames, kindly refer to nearest branch office.

 

Enclosure

All motors are totally enclosed fan cooled (TEFC) as per IS 4691 and are suitable to operate in both outdoor and indoor applications.

 

Cooling

The motors are designed with IC0141 method of cooling as per IS 6362 which provides excellent heat dissipation of the motors and ensures longer life of the motor.

 

Degree of Protection

Degree of protection for machines are designated in accordance with IS 4691 by letter IP followed by two characteristic numerals corresponding to protection from dust and water. All motors are provided with IP55 degree of protection as a standard and are suitable for operation in dusty and humid environment conditions. Bearing Details all motors are fitted with deep groove ball bearings with C3 clearance and greased for life ensuring longer trouble free operation.

Brake Motors

Brake Motor is combination of an AC induction motor and electromagnetic DC brake. DC supply is fed to the brake from a rectifier unit installed in the motor terminal box. The brake is disc type and is mounted on the motor shaft. The brake is ‘Fail proof type i.e. brake comes into action and stops the driven equipment instantly when the power to the motor is switched off or/if power fails. The supply to the rectifier is fed from any two terminals of the main terminal box .

Havells with its AEG technology, state-of-art plant and automatic processing can offer zero-defect brake motors in frames 63 to 160, in 2P, 4P, 6P and 8P versions. 

 

Operation

Under ‘OFF’ power condition brake springs keep the brake liner pressed against the mounting flange thus preventing the rotation of the motor shaft. When power is switched on, the brake coil gets energized through the rectifier unit. It instantly attracts the armature disc by overcoming the spring force. This results in releasing of the brake rotor allowing the motor to rotate.

 

In the event of power failure/switch of mode, the brake coil gets de-energised. This results in the springs pressing the brake liner against mounting flange i.e. returning armature disc to its original position. This results in instantaneous braking of rotor. Fail safe condition is thus ensured.

 

Applicable Standards

IS 325

IEC 34

BS 4999

IS 1231

IS 2223

 

Special Features

• The brake motors are simple, rugged & easy for maintenance. • No separate DC supply is required as the rectifier is provided, which gives the required DC voltage for energisation of the brake.

• The rectifier is mounted inside the main terminal box so no separate terminal box required.

• Special brake liner is used which ensures, the braking torque value remains quite stable through out the use.

 

General guidelines for selection of suitable brake model.

The brakes are rated by torque & selection of suitable model can be made by calculating the required torque, rating or the brake & then matching it with static torque.

Torque (Nm) = 9550 x (KW/RPM) x Safety Factor (SF)

where

KW-kilowatts of motor,

RPM-speed of motor,

SF-safety factor

 

Applications

Brake Motors are used for numerous applications. A few of them are listed below:

• Textile machinery • Machine Tools • Printing Machine • Cranes and Hoists • Material Handling Equipments • Leather Processing Machines • Cable Reeling Drums • Rolling Mills • Elevators•   Conveyers, etc.

 

DC Brake Motors:

Voltage :  415V +/-10%

Frequency :  50Hz +/-5%

Combined Variation :  +/-10%

Ambient Temp. :  50ºC

Duty :  S1

Mounting :  B3, B5, B14 & B35

Ins. Class :  F

Temp. Rise :  B

Protection :  IP55

Inverter Duty Motors With Forced Cooling

Havells manufactures squirrel cage inverter duty motors which are specially designed for operations requiring wide speed variation through variable speed drives. These motors are generally used when the motor is running for longer duration at speeds below 70% of rated name plate speed.

 

Inverter duty motors operate at constant torque upto rated design frequency when connected with variable frequency drives.The motors are fitted with separate cooling arrangement which ensures that the motors perform successfully at lower speeds without over-heating of the motor. This also ensures that the loading capacity of the motor is not reduced in this range. All external cooling fans are rated at 3000 rpm which provide excellent cooling to the motors even at lower speed of operation.

 

Features

Voltage  : 3 Ph., 415 V (Other voltage as per requirement)

Frequency : 50  Hz (Other frequency as per requirement)

Ambient  : 50 Deg. C

Ins. Class  : F (Temp. rise Class B)

Range : 0.37 kW to 55 kW

Pole : 2, 4, 6 and 8 Pole

Frame  : 80 to  250

Frequency Range : 20 to 75 Hz

Mounting : B3, B5, B14 and combination                

Cooling : IC 416

Enclosure : Totally Enclosed Separately Cooled

Protection : IP 55

Standards  : IS: 325, IS: 1231, IS: 2223  IS: 4722

 

Deration Factor for Higher Ambient

 

 

Encoder Mounting

The motors are provided with encoder mounting arrangement as a standard feature which is required by customers for motor control.

 

While selecting the motor, maximum allowed speed of the motor is also to be considered. For 2 pole motors, the maximum allowed speed is 4000 rpm and for 4 pole motors, it is 3600 rpm. When the nominal supply voltage of the converter is more than 500V, it is recommended to use du/dt filters which reduce voltage stresses in the winding by reducing the rate of change of phase and main voltages.

 

The use of converters with motors also demands extra requirements in terms of cabling and grounding of the drive system. Although asymmetrical cables can be used for the cabling but it is recommended to use shielded symmetrical cables along with EMC glands.