Description of Recom Motor Control Switches
RECOM Motor Control Switches are of Cam Operated Double Break contacts and are suitable to directly start, reverse, star-delta, 2 speed operations of 3-Phase Motors and are available in 10 A(l H.P.), 16A(3 H.P.), 20 A(5 H.P.), 25A(7.5 H.P), 32A(10 H.P), 40 A(12.5 H.P.) And 50A(15 H.P.) Rating. These are available in TWO types of Enclosures viz. Sheet Steel and Engineering Thermo Plastic moulded, fitted with suitable white engraved legends on black skirt and indexable Ball Handle. Switches of higher rating viz. 63A, 80A, 100A and 125A are suitable for MOTOR DUTY conforming to AC - 23 A utilization category to switch-on Motors of 22 KW (63 A), 30 KW (80 A), 37KW(100A) and 45 KW (125 A) respectively. These conform to ISS:13947 Pt. 3 & 5, utilization category AC - 23 A & AC-3 to directly Switch-on and to AC-4 utilization category to reverse, inching, star-delta starting and 2-speed Dahlander wound motors and 2-speed reversing with off and have been Tested and Certified at the Short Circuit Testing Laboratory of C.P.R.I., Bangalore. Switches have very long Electrical life of over 1 lakh operations. The plastic moulded enclosures are weather and dust-proof due to provision of neoprene rubber "O" ring sealing between the housing and cover and on the metal shaft projecting out of the housing. For sheet steel enclosure, neoprene rubber grooved gasket is to be provided.

Range
Standard range of Motor Control switches cover 7 basic switching combinations in each series of MC 16 and MC32 viz :

• Off/On
• Reversing
• Star-Delta
• System Selector
• 2 Speed Pole Changing - Seperate Windings
• 2 Speed Pole Changing - Dahlander Windings
• 2 Speed Reversing Pole Changing.

Made-to-Order
In addition to the standard range listed, switches are also made-to-order with features of Spring Return and combination of Stay-put/Spring return and any complex switching configuration which the applications demand and the design permits.

Operating Angle
Switches are manufactured for operating angle of 45° between position as a standard/Against specific requirements, Switches with 60° or 90° operating angle are also manufactured.

Terminals and Connections
Switches have recessed type terminals designed for straightened wire connections by means of M4 size screws and clamped tight by arched spring washers. no lugs are required. Terminals are suitable to carry wires upto 4mm sq. size. All terminal screws are accessible for wiring from one direction (top) leaving the underneath portion free thus saving space. Terminal marked is provided on the rear plate of the switch with M4 size screw, for connecting earthing wire(s).

Handle/Indication Dial
As a standard, all switches are supplied with a moulded ball type handle and rotating indicating dial having engraved markings filled with white paint as shown in the table of standard range. Handle is indexable on indicating dial by matching serations for any angular displacement to suit individual requirements. On request switches are also supplied with optional accessories like :

• Machine handle (metallic chrome plated with red ball).
• 'Wing' type handle.
• Indicating dial with markings, other than standard.

Construction
Motor Control switches, series MC 16 and MC 32 have modular construction. Modules (packets) of 72 x 60 x 13mm dimensions, moulded from selected engineering plastics of antitracking quality, are stacked to form an assembly housing fixed and moving contacts to operate under dust-free atmosphere. A positive and robust indexing mechanism with suitable operating handle fixed on the drive shaft, is coupled to the assembly of contacts to ensure efficient and long electrical and mechanical operations. Earthing terminal is provided externally.

Life
Mechanical life of these switches is 5 million switching cycles approx. Long contact life is however assured due to excellent interrupting capacity which also eliminates necessity of any maintenance.

Frequency of Operation
Recommended for 200 switching cycles per hour (Max.).

Temperature
Switches can be safely used under temperatures not exceeding 55° C ambient.

Specification
Motor Control switches both series (MC16 & MC32) generally comply with specification IS:4064 (Part II)-1978 and are classified under AC3 utilization category as Motor Duty switches.

Executions / Mountings

• Open Execution (Code X) : For mounting the switch from behind the panel (mounting plate) on 2 holes at 51 Crs by 2 M4 size screws provided.
• Front Plate Execution (Code FC) : For mounting the switch from the front side of the mounting plate (castings, etc.) on 4 holes size 5mm at 70 Crs at corners. Screws of M4.5 are recommended. Switch is supplied complete with Front Plate, of cast aluminium duly painted, of size 90 x 90mm.sq.
• Panel Execution (Code P) : For mounting the switch flush at the back of the panel (mounting plate) with 4 screws size M4 mm at 60 Crs at corners provided. Additional 2 tapped holes with M4.5 size screws are provided for fixing the indicating plate.
• Sheet Steel Housing (Code S) : For mounting the switch on plain surface externally on any machine tool or equipment, where space for inside mounting is not available. The basic switch is mounted in a sheet steel housing having Base and Cover. The Base is to be fixed by means of suitable screws/bolts through 4 holes at 100 x 76 Crs and cover by 4 screws provided with housing. Suitable cable/conduit entry holes 2-OFF 20mm 0 are provided on the rear side blocked by rubber groumets to be pierced at the time of wiring.

Guarantee
Switches carry a guarantee of 12 months from the date of dispatch for satisfactory performance and shall be free from defects in materials and workmanship. Repairs/replacements shall be made free of charge immediately on receipt within this period. This does not cover switches misused or damaged.