Common use of MOULDED CASE CIRCUIT BREAKERS Clause in Contracts

MOULDED CASE CIRCUIT BREAKERS. i. Moulded case circuit breakers (MCCB) or fuse free breakers, incorporated in switchboards wherever required, shall conform to IS 13947 : 1993 in all respects. MCCBs shall be suitable either for single phase 240 Volts or 3 Phase 415 Volts AC 50 HZ supply. MCCB cover and case shall be made of high strength heat resisting and flame retardant thermosetting insulating material. Operating handle shall be quick make/break, trip - free type. Operating handle shall have suitable ON, OFF and TRIPPED indicators. Three phase MCCBs shall have a common handle for simultaneous operation and tripping of all the three phases. Suitable arc extinguishing device shall be provided for each contact. Tripping unit shall be of microprocessor based electronic type provided on each pole and connected by a common tripe bar such that tripping of any one pole causes three poles to open simultaneously. Electronic tripping device shall have IDMT characteristics for sustained over loads and short circuits. Contact trips shall be made of suitable arc resistant sintered alloy. Terminals shall be of liberal design with adequate clearances. MCCBs shall be provided with following accessories, if specified in drawings/schedule of quantities : • Shunt trip • Alarm switch • Auxiliary switch MCCBs shall be provided with following interlocking devices for interlocking the door a switch board. • Handle interlock to prevent unnecessary manipulations of the breaker. • Door interlock to prevent door being opened when the breaker is in ON position • Deinterlocking device to open the door even if the breaker is in ON position. MCCBs shall have rupturing capacity as specified in drawings/schedule of quantities. ii. MCCB shall be triple pole air break. iii. The MCCB shall have a quick - make, quick - break mechanism operated by a suitable external rotary handle, complete with position indicator this handle shall have provision for pad locking in ON & OFF position. iv. MCCB should have microprocessor base electronic release with over current, earth fault & short circuit protection equivalent to L&T `D‟ since with RC-10 release.

MOULDED CASE CIRCUIT BREAKERS. i. Moulded case circuit breakers (MCCB) or fuse free breakers, incorporated in switchboards wherever required, shall conform to IS 13947 : 1993 in all respects. MCCBs shall be suitable either for single phase 240 Volts or 3 Phase 415 Volts AC 50 HZ supply. MCCB cover and case shall be made of high strength heat resisting and flame retardant thermosetting insulating material. Operating handle shall be quick make/break, trip - free type. Operating handle shall have suitable ON, OFF and TRIPPED indicators. Three phase MCCBs shall have a common handle for simultaneous operation and tripping of all the three phases. Suitable arc extinguishing device shall be provided for each contact. Tripping unit shall be of microprocessor based electronic type provided on each pole and connected by a common tripe bar such that tripping of any one pole causes three poles to open simultaneously. Electronic tripping device shall have IDMT characteristics for sustained over loads and short circuits. Contact trips shall be made of suitable arc resistant sintered alloy. Terminals shall be of liberal design with adequate clearances. MCCBs shall be provided with following accessories, if specified in drawings/schedule of quantities : •  Shunt trip •  Alarm switch •  Auxiliary switch MCCBs shall be provided with following interlocking devices for interlocking the door a switch board. •  Handle interlock to prevent unnecessary manipulations of the breaker. •  Door interlock to prevent door being opened when the breaker is in ON position •  Deinterlocking device to open the door even if the breaker is in ON position. MCCBs shall have rupturing capacity as specified in drawings/schedule of quantities. ii. MCCB shall be triple pole air break. iii. The MCCB shall have a quick - make, quick - break mechanism operated by a suitable external rotary handle, complete with position indicator this handle shall have provision for pad locking in ON & OFF position. iv. MCCB should have microprocessor base electronic release with over current, earth fault & short circuit protection equivalent to L&T `D‟ since with RC-10 release.

MOULDED CASE CIRCUIT BREAKERS. i. Moulded case circuit breakers (MCCB) or fuse free breakers, incorporated in switchboards wherever required, shall conform to IS 13947 : 1993 in all respects. MCCBs shall be suitable either for single phase 240 Volts or 3 Phase 415 Volts AC 50 HZ supply. MCCB cover and case shall be made of high strength heat resisting and flame retardant thermosetting insulating material. Operating handle shall be quick make/break, trip - free type. Operating handle shall have suitable ON, OFF and TRIPPED indicators. Three phase MCCBs shall have a common handle for simultaneous operation and tripping of all the three phases. Suitable arc extinguishing device shall be provided for each contact. Tripping unit shall be of microprocessor based electronic type provided on each pole and connected by a common tripe bar such that tripping of any one pole causes three poles to open simultaneously. Electronic tripping device shall have IDMT characteristics for sustained over loads and short circuits. Contact trips shall be made of suitable arc resistant sintered alloy. Terminals shall be of liberal design with adequate clearances. MCCBs shall be provided with following accessories, if specified in drawings/schedule of quantities : •  Shunt trip •  Alarm switch •  Auxiliary switch MCCBs shall be provided with following interlocking devices for interlocking the door a switch board. •  Handle interlock to prevent unnecessary manipulations of the breaker. •  Door interlock to prevent door being opened when the breaker is in ON position •  Deinterlocking device to open the door even if the breaker is in ON position. MCCBs shall have rupturing capacity as specified in drawings/schedule of quantities. ii. MCCB shall be triple pole air break. iii. The MCCB shall have a quick - make, quick - break mechanism operated by a suitable external rotary handle, complete with position indicator this handle shall have provision for pad locking in ON & OFF position. iv. MCCB should have microprocessor base electronic release with over current, earth fault & short circuit protection equivalent to L&T `D‟ since with RC-10 release.

MOULDED CASE CIRCUIT BREAKERS. i. Moulded case circuit breakers (MCCB) or fuse free breakers, incorporated in switchboards wherever required, shall conform to IS 13947 : 1993 in all respects. MCCBs shall be suitable either for single phase 240 Volts or 3 Phase 415 Volts AC 50 HZ supply. MCCB cover and case shall be made of high strength heat resisting and flame retardant thermosetting insulating material. Operating handle shall be quick make/break, trip - free type. Operating handle shall have suitable ON, OFF and TRIPPED indicators. Three phase MCCBs shall have a common handle for simultaneous operation and tripping of all the three phases. Suitable arc extinguishing device shall be provided for each contact. Tripping unit shall be of microprocessor based electronic type provided on each pole and connected by a common tripe bar such that tripping of any one pole causes three poles to open simultaneously. Electronic tripping device shall have IDMT characteristics for sustained over loads and short circuits. Contact trips shall be made of suitable arc resistant sintered alloy. Terminals shall be of liberal design with adequate clearances. MCCBs shall be provided with following accessories, if specified in drawings/schedule of quantities : • Shunt trip • Alarm switch • Auxiliary switch MCCBs shall be provided with following interlocking devices for interlocking the door a switch board. • Handle interlock to prevent unnecessary manipulations of the breaker. • Door interlock to prevent door being opened when the breaker is in ON position • Deinterlocking device to open the door even if the breaker is in ON position. MCCBs shall have rupturing capacity as specified in drawings/schedule of quantities. ii. MCCB shall be triple pole air break. iii. The MCCB shall have a quick - make, quick - break mechanism operated by a suitable external rotary handle, complete with position indicator this handle shall have provision for pad locking in ON & OFF position. iv. MCCB should have microprocessor base electronic release with over current, earth fault & short circuit protection equivalent to L&T `D‟ D’ since with RC-10 release.