Sterling Controls Pvt. Ltd.

Lower Parel, Mumbai, Maharashtra

These brakes are ideally suited for locations where pneumatically operated controls are desired and also for places having a hazardous environment where such equipment is necessary. These brakes are constructed from fabricated steel and are suited for heavy duty applications. They are quick acting and efficient. Solenoid valves can be supplied for most voltages enabling such brake to be used in mobile applications. Similar brakes can be supplied with hydraulic actuators instead of pneumatic actuators if hydraulic lines are available instead for pneumatic lines and if so preferred.

Two Way Series Limit Switch is used to prevent over travel or over traverse. The Limit Switch is fitted with 2 sets of contacts which remain normally closed and supply power directly to the 2 phases of Motor in either direction. When the lever is moved over a projecting member fixed at a pre-Determined position on either side of the gantry, the power supply to the motor is cut off. The contacts are automatically reset when the lever returns to `Zero position due to spring action. The contacts are rated for 60 Amps at 415 Volts A. C. 50 cycles supply system.The side covers are of cast iron. The top and bottom covers are of sheet steel. The lever is of Mild Steel fitted with M. S. Roller.

Resistance Boxes Manufacturer are assembled with stainless steel wire grid type or punched stainless steel type elements, which are restless, unbreakable, and capable of withstanding mechanical shocks and vibration. The grids are mounted on high tensile steel rods insulated with heat resistant Mica tubes. These assemblies are mounted in well ventilated sheet steel housings, ensuring low temperature rise. All Resistance steps are terminated on a common terminal strip which facilitates installation and wiring.

Electro Hydraulic Thrustors consists of a cylinder filled with oil containing the centrifugal pump located at the bottom and electric motor assembled on the top cover. The Rotor Shaft of the Motor is extended vertically downwards in the cylinder and carries an impeller at its lower end. The top bearing of the motors are grease lubricated and the bottom bearing is splash lubricated from oil in the tank. The Thrustor motors are totally enclosed `B class insulated, suitable for AC 400440 Volts, 3 phase, 50 Hz supply.Electro Hydraulic Thrustor is robust and dependable, possessing the stamina needed for the toughest duty conditions imposed by unattended drives in any industry. Because of its extra-ordinary versatility it has wide applications in electrically driven Hoists, Cranes, Elevators, Ropeways, Flap Valves, Guillotine Machines, Conveyors, Steel Mills, etc.

Application:STERLING Electro Hydraulic Thrustor is robust and dependable, possessing the stamina needed for the toughest duty conditions imposed by unattended drives in any industry. Because of its extra-ordinary versatility it has wide applications in electrically driven Hoists, Cranes, Elevators, Ropeways, Flap Valves, Guillotine Machines, Conveyors, Steel Mills, etc.

Construction:

The STERLING Electro Hydraulic Thrustors consists of a cylinder filled with oil containing the centrifugal pump located at the bottom and electric motor assembled on the top cover. The Rotor Shaft of the Motor is extended vertically downwards in the cylinder and carries an impeller at its lower end. The top bearing of the motors are grease lubricated and the bottom bearing is splash lubricated from oil in the tank. The Thrustor motors are totally enclosed `B class insulated, suitable for AC 400/440 Volts, 3 phase, 50 Hz supply.

When the motor drives the impeller, it pumps the oil from the upper to the lower side of the piston. In model 47-2040 Thrustor, the whole motor and end shield assembly move up during power stroke. In all other models inside the cylinder, above the impeller is a piston with thrust rods connected by a cross bar which delivers the useful thrust. When the power to the motor is switched off, the impeller stops, oil flows in the reverse direction through the stationery impeller, and the load forces the piston down.

The thrustor is not susceptible to mechanical overloads because if external load exceeds the lifting force of the thrustor its piston will remain stationery while the pump will continue to operate building up normal working pressure of the fluid under the piston. This gives rise neither to excessive current in the motor nor to excessive stresses in the thrustor elements.

Features:

We STERLING controllers like other Manufacturers for Electro Hydraulic Thrustors deliver gentle thrust without any jerks, consuming very negligible power. It is rated for 100% continuous duty and can withstand many switching operations without over heating the motor. They can be fitted up to 10 degree from the vertical in either direction due to swivel mounting arrangement.

STERLING Grid type Resistance Boxes are usually used with slip-ring [Wound Rotor] Motors [AC and DC] to provide control of starting torque, starting current and speed. They are designed to meet different classes of service, in various applications where slip-ring motors are used such as Conveyors, Screws Feeders, Steel Rolling Mills, Rubber Mills, Cranes, Hallagues, and Compressors etc. Desired control operation of Slip-ring Motors is obtained through external connections of appropriate values of Resistanceinto the Rotor slip-ring circuits. Slip-ring [Wound Rotor] Motors can operate with an infinite number of different speed, torque or current characteristics. Different performance criteria are obtained by the selection of external resistance which is connected into the slip-Ring circuit.

STERLING Grid type Resistors are custom designed and manufactured to suit customers specific requirements, whether for starting duty or for continuous-speed-duty operations, in accordance with relevant BSS, NEMA or IS specifications.

Rating / Duty Cycle

The Resistances are designed and manufactured to suit rating and duty cycles as required by the customer in his application and temperature rise does not exceed the limit specified in BSS 587-1957.

Operation

STERLING Resistances may be operated through Drum Controllers or by Master Controllers with associated contractor gear or with Timers and contractors in Slip-ring Motor starter panels.

Construction

STERLING Resistance Boxes Manufacturer are assembled with stainless steel wire grid type or punched stainless steel type elements, which are restless, unbreakable, and capable of withstanding mechanical shocks and vibration. The grids are mounted on high tensile steel rods insulated with heat resistant Mica tubes. These assemblies are mounted in well ventilated sheet steel housings, ensuring low temperature rise. All Resistance steps are terminated on a common terminal strip which facilitates installation and wiring.

Ordering Information

While ordering STERLING Resistance Boxes the following information is requested which will enable us to provide you with the most suitable offer?

1. Application details 2. Supply: AC/DC 3. Motor HP/KW 4. Rotor Voltage and Rotor Current 5. Starting Torque required 6. Number of steps required 7. Whether operated through Drum Controller or Master Controller / Contractors 8. Any other specific requirements

OTHER PRODUCTS

• Flexible Brake Drum & Brake Drum Couplings.
• Full Geared & Half Geared Couplings.
• Geared Brake Drum Couplings.
• Carbon Brushes
• Punched Grids
• Spare Coils for EM Brakes.
• Brake Liners & Brake Shoes.
• Cable Carriers & Trolleys.
• Clutches & Disc Brakes
• Current Collectors & Spares

STERLING Engineers will be pleased to assist in the selection of this item in special requirements and applications.

STERLING Master Controllers are vertical mounting cam operated sequence switches for use in conjunction with contactor equipment These controllers have been specially developed for frequent operation under the most severe conditions. They are suitable for most Motor drives such as Rolling Mills, Cranes and other applications demanding frequent operation and trouble free service with limited time available for routine maintenance.

We sterling controllers like many other Manufacturers of Master controllers whichare exceptionally light in operation with consequent reduction in operational failure. The contact is a single integral unit and independent of the main cam shaft. The contact tips are bimetallic and can be replaced without disturbing any connections. The entire contact assembly is secured by 2 screws only and it can be removed easily to facilitate maintenance/replacement.

ENCLOSURES:

These Controllers have sheet steel enclosures and are wall fixing as standard. Special mounts can be provided to suit customers specific requirements.

Operation:

Operation is by Ball handle and normally provided with spring return. Operating sequences are standard and special sequence can be catered for. The number of steps and cams can be varied to suit customers requirements.

Two Way Series Limit Switch:STERLING Two Way Series Limit Switch is used to prevent over travel or over traverse. The Limit Switch is fitted with 2 sets of contacts which remain normally closed and supply power directly to the 2 phases of Motor in either direction. When the lever is moved over a projecting member fixed at a pre-Determined position on either side of the gantry, the power supply to the motor is cut off. The contacts are automatically reset when the lever returns to `Zero position due to spring action.

The contacts are rated for 60 Amps at 415 Volts A. C. 50 cycles supply system.The side covers are of cast iron. The top and bottom covers are of sheet steel. The lever is of Mild Steel fitted with M. S. Roller.

Hoist Series Limit Switch:

STERLING Hoist Series as differentialLimit Switches is used to prevent over hoisting. The Limit Switch will normally remain `ON due to the weight connected to the lever. When the snatch block reaches the highest position the weight pulling the lever down is moved up on the snatch block, hence the lever is released and the two snap action contacts cut off 2 phases of the motor thereby stopping the hoisting motion. The contacts are automatically reset when the snatch block is lowered.

The contacts are rated for 60 Amps at 415 Volts A. C. 50 cycles supply system. Heavy Duty Hoist Limit Switch with contacts rated for 150 Amps at 415 Volts A. C. 50 cycles with arc chutes and blow out coils can also be supplied.

Rotary Shunt Limit Switch:

STERLING Rotary Shunt &geared Limit Switches is also used to prevent over hoisting. One set of contacts cut off supply to the coil circuit of the HOIST contactor, after about 6 revolutions of the spindle the other set of contacts cut off supply to the coil circuit of DOWN contactor. The contacts are automatically reset when the spindle rotates in the reverse direction.

The position of the switch operation is adjustable within 6 revolutions with one over turn in either direction. The spindle can be chain or gear driven with required reduction ratio to suit individual requirement. The Limit Switch is housed in totally enclosed fabricated steel housing with contacts rated for 10 Amps at 415 Volts A. C. 50 cycles supply system.

Two Way Shunt Limit Switch

STERLING Two Way Shunt Limit Switch is also used to prevent over travel or over traverse. The Limit Switch is fitted with 2 numbers of double break silver tipped contacts which remain normally closed and supply power to the contactor coil in the control panel. When the lever is moved over a projecting member fixed at a pre-determined position on either side of the gantry, the power supply to the contactor coil is cut off. The contacts are automatically reset when the lever returns to `Zero position due to spring action. The contacts rated for 10 Amps at 415 Volts A. C. 50 cycles supply system.