Type "SR" Ranges :

* Units with liquid Resistance Rotor Only
* SR1 to SR6 can be supplied with heavy duty Rotors also. The type is SR/HD/1 to 4 SR-1 to SR-8 are meant for 415 volts,3 phase motors while the SRS/L1 to SRS/L4 can be supplied suitable for motors with stator ranging upto 11000volts.The standard Rotor Resistances are designed for 100% starting torque but units designed for higher starting torque can be provided on request.

Design :
Stator Rotor starter type SR/1 to SRS/L 4 are floor mounting type are meant for 3 phase slipring induction motors. The rotor is oil immersed or Liquid Rotor and Stator is oil immersed oil circuit breaker. In specific requirement we can also supply Air Break Stator Control.

Protection :
a) Overload Protection :
Overload protection is through a triple pole series/CT operated. Electromagnetic overload coils, suitable time lagged with oil dash pots operated directly on mechanism tripping the breaker on sustained overloads. These overload device are instantaneous self resetting type and has an inverse time lag characteristic protecting the circuitry faster than any other type of protection. suitable range of calibration is also provided for thus ensuring more accurate foolproof over load protection.

b) Under-voltage Protection :
Electromagnetic under-voltage protection is given by the under-voltage coil fitted separately and acts directly on the mechanism tripping the breakers on failure of supply. The normal coil voltage is 415V, 50 Hz , AC however coil suitable for other AC voltages such as 220V, 100V and 550V can be provided on request.

c) Short Circuit Protection :
Short circuit protection is ensured through electromagnetic series/CT operated overloaded devices.

Interlocking :
Rotor interlock is achieved through position limiting contacts and a push button held through out the course of operation of the starting. This ensures a safe start with full resistance in the circuit the interlock connecting leads are shielded off in a metallic/PVC flexible conduit pipe. A tank interlock on the stator OCB ensures a tripped breaker. However isolation of supply at other point is recommended before opening out the breaker.

Enclosure :
Both stator and rotor control are offered in sheet steel enclosure for vermin and Dust proofing and it has got a standard finish of dark admiral gray paint.

Contacts :
Stator and Rotor contacts are provided are of substantial size cross section made of specially extruded electrolytic 99.9% purity copper that have durable silver plating on it. These contacts are easily replaceable during maintenance.

Resistance :
Resistance in the Rotor Box is of High Grade resistance wire to be kept immersed in oil wound on porcelain tubes, spread over in 18/36 as per the technical requirement.

Special Features :
a) All the MS Fabrication and hardware are either treated and painted or suitably electroplated to prevent any rusting even if the unit is kept for a long time without use.
b) For the instantaneous tripping an 'OFF' lever is provided on the front side of the breaker which trips the breaker at once in emergency.
c) We have provided copper jumps for cable termination with an enclosure which avoid the extra expenses of cable box.

d) On our Rotor an oil deep stick is provided to check oil level during service without opening the complete unit.
e) To ensure the smooth start of motor the rotor is provided with worm gear assembly connected to starting rotor handle which automatically ensure smooth starting even by an unskilled operator.
f) Parts subject to wear such as contacts are readily accessible for purpose of inspection maintenance and renewal.
g) Interchangeability of spares with lower HP and Higher HP Stator control is assured.
h) Intermittent class of duty as per IS 13947 (Part 4 Sec 1)1993.Number of operation per hour 2.

i) We can also provide extra accessories like Ammeter, Voltmeter Cable Box etc.
j) Operation : To start motor return the starter to 'OFF' position by turning hand wheel anticlockwise. Hold the Start button pressed then turn the handle in clockwise direction till 'Full on' position is reached. Release start button.
k) Usually the equipment is supplied without oil and hence fill oil before energising the unit. Use transformer oil to IS 335 :1972
l) Check proper HP/KW and rotor data of motor and starter which must be same.
m) While ordering please inform the following details of motor :
1) Rated output in HP/KW
2) Rotor Volts
3) Rotor Amps
4) Stator Volts
5) UVR Coil voltage required
6) Torque (starting)
7) Any extra accessories required like Ammeter, Voltmeter, Cable Gland etc.
8) Number of start per hour required
n) As the design and manufacture of KEI Equipments are under constant improvement the product supplied may differ in details from the specifications and illustration in this folder.