DIVISION 26 ELECTRICAL SECTION CIRCUIT BREAKERS

Transcription

1 DIVISION 26 ELECTRICAL SECTION PART 1 GENERAL 1.01 DESCRIPTION A. Furnish and install circuit breakers in switchboards, distribution panelboards, and separate enclosures for overcurrent protection for panelboards, transformers and equipment, as shown on the Drawings and specified herein. Provide all accessories as necessary. B. Short circuit ratings shall be as shown on the Drawings. C. Refer to Section , "Panelboards-Lighting and Appliance" for circuit breakers in panelboards. D. Provide frame size of circuit breaker with lug size as required to accommodate feeder size as shown on the Drawings. E. Provide frame size, plug size, and trip units as necessary to meet short circuit ratings, and to provide selective coordination (down to 0.01 seconds) on emergency power distribution systems. F. All circuit breakers shall be fully rated for short circuit levels indicated. Series ratings are not permitted QUALITY ASSURANCE A. All equipment shall be UL listed and labeled and in accordance with applicable NEMA and ANSI Standards SUBMITTALS A. For Review: 1. Product data sheets for all circuit breakers and components 2. Wiring diagrams B. To be included in Record and Information Manuals: 1. One (1) copy of each approved submittal 2. Test results 3. Manufacturer Representative's signed Certificate of Inspection and Approval 1.04 MANUFACTURERS A. Circuit Breakers 1. Square D Company 2. Siemens Energy & Automation, Inc. 3. Cutler-Hammer/Eaton Corporation 13-HC

2 PART 2 PRODUCTS 2.01 MOLDED CASE WITH THERMOMAGNETIC TRIP A. Molded case circuit breakers shall be bolt-on type operated by a toggle type handle and shall have quick-make/quick-break over-center switching mechanism that is mechanically trip free from the handle so that the contacts cannot be held closed against short circuits and abnormal currents. Tripping due to overload or short circuit shall be clearly indicated by the handle automatically assuming a position midway between the manual ON and OFF positions. B. Breakers must be completely enclosed in a molded case. Non-interchangeable trip breakers shall have their covers sealed; interchangeable trip breakers shall have the trip unit sealed to prevent tampering. Ampere ratings shall be clearly visible. Arc extinction must be accomplished by means of arc chutes. C. Molded case breakers shall be of the thermal magnetic standard type that provides inverse time delay overload and instantaneous short circuit protection by means of a thermal magnetic element. D. Single phase circuit breakers shall be balanced among the three (3) phases. E. All circuit breakers shall have an integral lock-out/tag-out means. F. High magnetic withstand circuit breaker type shall utilize higher trip levels of 18 to 20 times the breaker handle rating MOLDED CASE WITH SOLID STATE TRIP A. Circuit protective devices shall be molded case type circuit breakers UL Listed for 80% continuous current with full function trip system. Frame/Sensor ampere ratings shall be as shown on the Drawings. The ampere rating shall be clearly marked on the front of the circuit breaker. Circuit breakers shall be of fixed construction. B. Circuit breakers shall be constructed using glass-reinforced insulating material providing high dielectric strength. Current carrying components shall be completely isolated from the trip unit and accessory mounting area. Breakers shall have common tripping of all poles and shall be trip free. The breakers shall have quick-make/quick-break contacts with an over center toggle operating mechanism. All circuit breakers shall be equipped with electrical accessories as noted on the Drawings. C. The integral electronic trip system shall be independent of any external power source and shall contain electronic components to measure and time the output from internal current sensors and initiate automatic tripping action. The continuous ampere rating of the circuit breaker shall be determined by the combination of the ampere rating switch position, and the frame/sensor size of the circuit breaker. The resulting ampere rating shall be clearly marked on the face of the circuit breaker. Provide a means to seal the trip unit adjustments to discourage unauthorized tampering to meet the requirements of NEC Article HC1-033

3 D. Provide the following time/current curve shaping adjustment to maximize system selective coordination. Each adjustment shall have discrete settings and shall be independent from all other adjustments: 1. Adjustable Long Time Ampere Rating and Delay 2. Adjustable Short Time Pickup and Delay (delay includes I 2 t in and I 2 t out) 3. Fixed Instantaneous Trip 4. Ground fault trip (where shown on one line diagram) E. Provide local visual trip indication for overload, short circuit occurrences. The trip system shall include a memory circuit to detect intermittent overcurrent conditions. Each circuit breaker trip system shall be equipped with an externally accessible test port for use with a Universal Test Set. No disassembly of the circuit breaker is required for testing. Test set shall be capable of verifying the operation of all trip functions with or without tripping the circuit breaker. F. All circuit breakers shall have an integral lock-out/tag-out means INSULATED CASE WITH SOLID STATE TRIP A. Circuit protective devices shall be insulated case type circuit breakers UL lists for 100% continuous current with full function trip system. Frame/Sensor ampere ratings shall be shown on the Drawings. Circuit breakers shall be of drawout construction. B. Provide selective override circuit on circuit breakers with defeatable instantaneous adjustment to allow the breaker (1) to remain closed for up to thirty (30) cycles during overcurrents below 50 ka RMS symmetrical, and (2) to trip instantaneously when current levels exceed thirty (30) cycle withstand rating. All circuit breakers shall be constructed in accordance with UL 489 and NEMA AB Circuit breakers shall be constructed using glass-reinforced insulating material providing high dielectric strength. Current carrying components shall be completely isolated from the trip unit and accessory mounting area. Breakers shall have common tripping of all poles and shall be trip free. The circuit breaker shall be UL listed for reverse connection without requiring special construction. C. Provide true two step stored energy mechanism for five (5) cycle closing. Energy required to close breaker shall be stored pending release to close action. All circuit breakers shall have multiple CHARGE/CLOSE provisions allowing the following sequence: CHARGE, CLOSE, RECHARGE, OPEN/CLOSE/OPEN. Visual indication of mechanism CHARGED and DISCHARGED position on the face of the breaker. Visual indicator shall show the face of the breaker. Visual indicator shall show CHARGED only when closing springs are completely charged. D. Provide interlocking capabilities for lockout of local manual closing buttons and padlocking main contacts in OPEN position. E. The integral trip system shall be independent of any external power source and shall contain electronic components to measure and time the output from internal current sensors and initiate automatic tripping action. The trip unit shall be factory installed and capable of being field interchangeable while retaining UL listing. 13-HC

4 F. The continuous ampere rating of the circuit breaker shall be determined by the combination of an interchangeable rating plug and the sensor size of the circuit breaker. The ampere rating resulting from the rating plug/sensor combination shall be clearly marked on the front of the circuit breaker. Provide a means to seal the rating plug and trip unit adjustments to discourage unauthorized tampering to meet the requirements of NEC Article G. Provide the following time/current curve shaping adjustments to maximize system selective coordination. Each adjustment shall have discrete settings and each function is independent from all other adjustments: 1. Adjustable Long Time Ampere Rating and Delay 2. Adjustable Short Time Pickup and Delay (delay includes I 2 t in and I 2 t out) 3. Adjustable Defeatable Instantaneous Pickup 4. Adjustable Ground-Fault Pickup and Delay (delay includes I 2 t in and I 2 t out) 5. Fixed Selective Override H. Provide local visual trip indication for overload, short circuit and ground-fault trip occurrences. Provide a long time pickup light to indicate when loading approaches or exceeds the continuous current carrying capacity of the circuit breaker. The trip system shall include a memory circuit to detect intermittent overcurrent conditions. Each circuit breaker trip system shall be equipped with an externally accessible test port for use with a Universal Test Set. No disassembly of the circuit breaker is required for testing. Test set shall be capable of verifying the operation of all trip functions with or without tripping the circuit breaker. I. Circuit breakers shall be provided with integral ground-fault protection. The circuit breaker shall be applicable on 3 phase, 3 wire circuits where the neutral is grounded, but not carried through the system or 3 phase, 4 wire systems. The ground-fault system shall be Zero Sequence. The ground-fault sensing system shall meet the on-site testing requirements of NEC Article (c). Provide a separate neutral current transformer for 3 phase, 4 wire systems ENCLOSURES A. Enclosures shall have padlocking provisions for locking circuit breakers in the "OFF" positions. B. Enclosure types shall be as follows: 1. NEMA 1 - Gray baked enamel on galvanized steel 2. NEMA 3R - Gray baked enamel on galvanized steel with drain holes, lockable door, securable in the open position 3. NEMA 4X - Stainless steel with gasketed cover C. Enclosures shall be flush mounted in gypsum board walls and surface mounted on concrete walls HC1-033

5 PART 3 EXECUTION 3.01 APPLICATION A. 15 Ampere through 175 Ampere circuit breakers shall be molded case with thermomagnetic trip sensor and mechanism. B. 200 Ampere and above through 1600 Ampere circuit breakers shall be molded case with solid state trip sensor and mechanism. C. Circuit breakers above 1600 Ampere shall be insulated case with solid state trip sensor and mechanism. D. Provide the following NEMA rated enclosure types for single circuit breakers in these locations: 1. Interior Exterior - 3R 3.02 INSTALLATION A. Install circuit breakers in switchboards, distribution panelboards or enclosures as shown on the Drawings and in accordance with Manufacturer's written instructions. B. Provide nameplates in accordance with Section , "Electrical Identification." 3.03 TESTING A. Perform a complete functional test of all features of circuit breakers in accordance with Manufacturer's recommendations. Submit written documentation in Record and Information Manuals. END OF SECTION 13-HC