Memorial Hermann Best Practices
July, 2013
SECTION 26 23 13 PARALLELING LOW VOLTAGE SWITCHGEAR
PART 1 - GENERAL
1.01 WORK INCLUDED
A. Comply with provisions of Section 26 05 00.
B. Furnish and install, where indicated on the drawings, a complete emergency power generation power distribution and control system. Provide dead front type, low voltage metal-enclosed switchgear with ANSI rated power circuit breakers for the generator breakers as specified herein and as shown on the contract drawings. Provide distribution equipment as specified herein and as shown on the contract drawings.
C. Furnish emergency paralleling switchgear specified in this section with the transfer switches and the generator sets by the engine generator supplier as a total system. The circuit breakers utilized in the emergency paralleling switchgear shall be the same manufacturer as the circuit breakers provided in the assemblies for the normal and emergency distribution as specified under other sections of the specifications.
1. Where used on the emergency system in a health care facility subject to NEC Article 517, all ground fault functions shall be alarm only with no trip function.
D. The emergency paralleling system shall consist of two or more generators that are paralleled with each other as shown on the drawings.
1.02 RELATED SECTIONS
A. Section 26 05 53: Identification for Electrical Systems.
B. Section 26 09 15: Electronic Power Monitor
C. Section 26 36 00: Transfer Switches
D. Section 26 23 00: Low Voltage Switchgear
E. Section 26 32 13: Emergency Engine & Generator System
F. Section 26 43 13: Transient Voltage Surge Suppression
1.03 REFERENCES
A. The low voltage metal-enclosed switchgear assembly and all components shall be designed, manufactured, and tested in accordance with the following latest applicable standards:
1. ANSI-C37.20 - Switchgear assemblies
2. ANSI-C37.13 - Low voltage power circuit breakers
3. ANSI-C37.50 - Test procedures for low voltage power circuit breakers.
4. NEMA SG-5 - Switchgear assemblies
5. NEMA SG-3 - Low voltage power circuit breakers
6. UL 1558 - Metal enclosed low voltage switchgear
1.04 SUBMITTALS
A. Provide a minimum of 8 copies of the following documents, where applicable, to Owner for review and evaluation in accordance with general requirements of Division 01 and Division 26:
1. Front view and floor plan of switchgear
2. Switchgear anchoring locations
3. Conduit and busway entry / exit locations
4. Location of shipping splits
5. One-line and three-line diagrams of switchgear bus and protective devices
6. Ground fault protection one line diagram
7. Switchgear ratings including:
a. Short circuit rating
b. System voltage rating
c. Continuous current rating
8. Protective device schedule including:
a. Device type
b. Sensor and trip rating
c. Location within the switchgear
d. Cable quantity and size capabilities for each device
9. Panel drawing showing all major protection, instrumentation, and control devices mounted within the switchgear
10. Schematic diagram showing power, metering, and control circuits for the switchgear and circuit breakers
11. Bill of Material listing (including quantity, location, catalog number, and ratings) of all major protection, instrumentation and control devices
12. Switchgear nameplate schedule
13. Cable terminal sizes
14. Product data sheets
15. Field control wiring diagrams
16. Sequence of operation description
B. Where applicable, the following additional information shall be submitted to the Engineer:
1. Busway connection
2. Composite front view and plan view of close-coupled assemblies
3. Key interlock scheme drawing and sequence of operations
4. Mimic bus size and color
C. The final (as-built) drawings shall include the same drawings as the construction drawings and shall incorporate all changes made during the manufacturing process.
D. Submit all drawings in 11" x 17" minimum size.
E. Submit all drawings on a CD in AutoCad, if requested.
1.05 PROJECT RECORD DOCUMENTS
A. Submit a minimum 8 copies of record information including:
1. As-built record drawings as follows:
a. Front View
b. Floor Plan
c. Elementary Diagram showing power, metering and control circuits
d. Switchgear internal wiring diagrams
e. Bill of Material
f. One Line Diagram
g. Three Line Diagram
h. Ground fault protection one line diagram
2. Instruction books on major components
3. Installation drawings
4. Certified test reports
5. Recommended renewal parts information
1.06 OPERATION AND MAINTENANCE DATA
A. Provide minimum 8 copies of installation, operation and maintenance procedures to owner in accordance with general requirements of Division 01 and Division 26.
B. Submit operation and maintenance data based on factory and field testing, operation and maintenance of specified product.
1.07 QUALITY ASSURANCE
A. Low voltage switchgear shall be completely factory assembled and metal enclosed. It shall consist of functionally compartmentalized units for removable power circuit breakers. The switchgear structure and breakers shall be the product of a single manufacturer.
B. Only manufacturers who have specialized in the manufacture and assembly of low voltage switchgear for 25 years will be considered.
C. Manufacturer's Certificate of ISO 9002 Compliance
1.08 REGULATORY REQUIREMENTS
A. Low voltage switchgear shall be listed by Underwriters Laboratories in accordance with standards listed in Article 1.04 of this specification and shall bear the UL label.
1.09 DELIVERY, STORAGE, AND HANDLING
A. Switchgear shall be provided with adequate lifting means and shall be able to be rolled or moved into installation position and bolted directly to floor without using floor sills.
B. Deliver, store, protect, and handle products in accordance with recommended practices listed in manufacturer's Installation and Maintenance Manuals.
C. Deliver each switchgear lineup in shipping sections for ease of handling. Each section shall be mounted on shipping skids.
D. Inspect and report concealed damage to carrier within specified time.
E. Store in a clean, dry space. Maintain factory protection or cover with heavy-duty plastic, minimum 6 mil, to keep out dirt, water, construction debris, and traffic. Heat enclosures to prevent condensation.
F. Handle switchgear in accordance with manufacturer's written instructions to avoid damaging equipment, installed devices, and finish. Lift only by installed lifting provisions.
1.10 PROJECT CONDITIONS (SITE ENVIRONMENTAL CONDITIONS)
A. Follow applicable NEMA, ANSI, and NECA standard practices before, during, and after switchgear installation.
B. Switchgear shall be located in well-ventilated areas, free from excess humidity, dust, and dirt and away from hazardous materials. Ambient temperature of area will be between minus [30] and plus [40] degrees C. Indoor locations shall be protected to prevent moisture from entering enclosure.
1.11 SEQUENCING AND SCHEDULING
A. Provide a written detailed description of scheduled installation, testing, and startup dates.
1.12 WARRANTY
A. Manufacturer warrants equipment to be free from defects in materials and workmanship for greater of 5 years from date of installation or 6 years from date of delivery. Alternate proposals for shorter warranty will not be acceptable.
1.13 MAINTENANCE CONTRACT
A. A complete maintenance contract shall be submitted with the bid which will be considered separately by owner. Length of the contract shall be a minimum of three years. Operation of each engine shall be assumed to be 1000 hours per year. Price of the contract shall be quoted in terms of dollars / hour. The contract will include all quarterly and annual maintenance, inspections, travel, parts and labor to ensure proper care. All parts and materials for preventive maintenance, make-up fluids and miscellaneous services shall be listed. The contract will include labor rates and pricing discounts for non-contract work and parts. Pricing will include a separate line item for a 2-hour annual resistive load bank best according to NFPA guidelines for each generator set.
1.14 EXTRA MATERIALS
A. Provide spare parts as recommended by manufacturer and as indicated on the drawings.
B. When draw-out circuit breakers are provided, a breaker-lifting device shall be provided suitable for all Low Voltage Power Circuit Breakers used. Circuit breaker lifting device shall be integrally mounted on each indoor and outdoor walk in switchgear.
C. Provide a complete set of spare fuses of all sizes and ratings used in the switchgear.
D. Provide fuse cabinet.
E. Provide a remote racking device with a 25 ft. cord.
1.15 OPERATION AND MAINTENANCE MANUALS
A. Equipment operation and maintenance manuals shall be provided with each assembly shipped, and shall include instruction leaflets and instruction bulletins for the complete assembly and each major component.
PART 2 - PRODUCTS
2.01 MANUFACTURERS
A. Engine Generators:
1. Detroit Diesel
2. Cummins / Onan
3. Caterpillar
4. Kohler
B. Synchronizing / Paralleling Switchboard:
1. ASCO Power Technologies
2. Cummins / Onan
3. Russ Electric
C. The listing of specific manufacturers above does not imply acceptance of their products that do not meet the specified ratings, features and functions. Manufacturers listed above are not relieved from meeting these specifications in their entirety. Products in compliance with the specification and manufactured by others not named will be considered only if pre-approved by the Engineer ten (10) days prior to bid date.
D. All equipment provided shall be supplied by an authorized distributor of the manufacturer who has been continuously engaged in the distribution of industrial grade Power System products for a minimum of 15 years. The supplier shall provide initial start-up services, conduct field acceptance testing, and warranty service. The supplier shall be authorized to perform warranty service on all products provided.
1. Within the Houston Metro region, the supplier shall maintain; an established team of factory trained and qualified field technicians; a proper supply of spare parts for the supplied equipment; a shop with overhaul capabilities; and able to provide 24 hour, 7 days per week, 365 days per year field service capability.
2.02 GENERAL REQUIREMENTS
A. General Requirements
1. Switchgear requirements are outlined below for convenience, however the switchgear must comply with all requirements as detailed in Section 26 23 00: Low Voltage Switchgear. In case of any conflict, the Low Voltage Switchgear specification shall prevail.
2. The switchgear shall consist of the required number of vertical sections bolted together to form a rigid assembly. The sides shall be covered with removable bolt-on covers. All edges of front covers or hinged front panels shall be formed. Provide ventilators located on the top of the switchgear over the breaker and bus compartments to ensure adequate ventilation within the enclosure. Hinged rear doors, complete with provisions for padlocking, shall be provided.
3. The assembly shall be provided with adequate lifting means. Provisions shall be made for jacking of shipping groups, for removal of skids or insertion of equipment rollers. Base of assembly shall be suitable for rolling directly on pipes without skids. The base shall be equipped with slots in the base frame members to accommodate the use of pry bars for moving the equipment to its final position.
4. Each vertical steel unit forming part of the switchgear line-up shall be a self-contained housing having one or more individual breaker or instrument compartments, a centralized bus compartment and a rear cable compartment. Each individual circuit breaker compartment, or cell, shall be segregated from adjacent compartments and sections by means of steel barriers to the maximum extent possible. It shall be equipped with drawout rails and primary and secondary disconnecting contacts. Removable hinge pins shall be provided on the breaker compartment door hinges. Current transformers for feeder instrumentation, where shown on the plans, shall be located within the appropriate breaker cells and be front accessible and removable.
5. The stationary part of the primary disconnecting devices for each power circuit breaker shall be breaker mounted and consist of a set of contacts extending to the rear through glass polyester insulating support barrier; corresponding moving finger contacts, suitably spaced, shall be furnished on the power circuit breaker studs which engage in only the connected position. The assembly shall provide multiple silver-to-silver full floating high pressure point contacts with uniform pressure on each finger maintained by springs. Each circuit shall include the necessary three-phase bus connections between the section bus and the breaker line side studs. Load studs shall be equipped with insulated copper load extension buses terminating in solderless type terminals in the rear cable compartment of each structure. Bus extensions shall be tin-plated where outgoing terminals are attached.
6. The circuit breaker door design shall be such that the following functions may be performed without the need to open the circuit breaker door: lever circuit breaker between positions, operate manual charging system, close and open circuit breaker, examine and adjust trip unit, and read circuit breaker rating nameplate.
7. The secondary disconnecting devices shall consist of floating terminals mounted on the stationary unit and engaging mating contacts at the front of the breaker. The secondary disconnecting devices shall be gold-plated and engagement shall be maintained in the “connected” and “test” positions.
8. The removable power circuit breaker element shall be equipped with disconnecting contacts and interlocks for drawout application. It shall have four positions, "connected," "test," "disconnected" and "removed." The breaker drawout element shall contain a worm gear levering "in" and "out" mechanism with removable lever crank. Levering shall be accomplished via the use of conventional tools. Mechanical interlocking shall be provided so that the breaker is in the tripped position before levering “in” or “out” of the cell. The breaker shall include an optional provision for key locking open to prevent manual or electric closing. Padlocking shall provide for securing the breaker in the connected, test, or disconnected position by preventing levering.
9. An insulating flash shield shall be mounted above each circuit breaker to prevent flashover from the arc chutes to ground.
10. Provide a rear compartment barrier between the cable compartment and the main bus to protect against inadvertent contact with main or vertical bus bars.
11. Provide in the cell when the circuit breaker is withdrawn, a safety shutter which automatically covers the line and load stabs and protects against incidental contact.
12. Provide a metal barrier full height and depth between adjacent vertical structures in the cable compartment.
B. Bus
1. All bus bars shall be tin-plated copper. Main horizontal bus bars shall be mounted with all three phases arranged in the same vertical plane. Bus sizing shall be based on ANSI standard temperature rise criteria of 65 degrees C over a 40 degrees C ambient (outside the enclosure). Rate the main bus as shown on drawings and brace for a minimum 100,000 amperes RMS symmetrical for a minimum of four (4) cycles.