Sterling Controls Pvt. Ltd. Mumbai, Maharashtra

“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 which are 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 customer’s 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 customer’s requirements.

“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 Resistance into 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.

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.

• Model No. Kgs.47-2040 to 47-3250
• Weight15 to 36

Application:   STERLING Drum Controllers are used in all types of electric operated cranes like many other Manufacturers to control all motions. They are also used in hoists and winches as well as for speed control of slip ring or squirrel cage motors in various machines. Construction:   STERLING Drum Controller is housed in a sheet steel enclosure with top and bottom plates of cast iron. The front cover is easily removable giving ample space for maintenance. The brake drum and couplings is the large diameter giving generous wearing surface and an increased arcing distance between the segments and tips. The drum contacts are of heavy gauge hard drawn copper, screwed to the cast iron drum with counter sunk head screws. Exact location of the contacts at each step is ensured by the provision of a ratchet wheel engaging on adjustable spring loaded pawl-lever fitted with roller. The square drum shaft is provided with square Bakelite tube to insulate the drum castings. The main contact fingers are of hinged pattern rigidly clamped to the Bakelite insulated steel square bar. Each finger consists of heavy section brass bar fitted with renewable hard drawn half round copper tip. The fingers engage with the rotary drum under helical spring pressure. The laminated copper shunts carry the current from the fingers to the terminal bases. The terminal bases are also of extruded brass. The brass parts and copper contacts are cadmium plated. Substantial arc shields on all main contacts are provided. The whole arc shield assembly can be removed for inspection of contacts and any damaged section of arc shield can be very easily replaced. All Drum Controllers are suitable for 400/440 Volts, 3 Phase, 50 cycles AC supply. Features: STERLING Drum Controllers  Manufacturer are provided with ‘ZERO’ interlocking contacts. Options available are shunt limit switch contacts, dead main’s handle, double rotor and dust proof cover. The Drum Controllers are of rebuts construction for long life but are easy for operation with low maintenance.