SECTION 16311 - DOUBLE ENDED LOAD CENTERS …



SECTION 26 11 16

SINGLE ENDED LOAD CENTERS (SECONDARY UNIT SUBSTATION)

PART 1 - GENERAL

1.1 FURNISH, PROVIDE AND INSTALL

A. Secondary Unit Substation (Single Ended Load Center) with all devices and accessories.

1.2 RELATED SECTIONS

A. Section 26 13 13: Medium Voltage Metal Clad Switchgear and Circuit Breakers.

1.3 STANDARDS

A. ANSI C37 series; including, but not limited to, C37.13, C37.16, C37.17, C37.20 (IEEE 27), and C37.51.

B. ANSI C39.1 - Requirements for Electrical Analog Indicating Instruments.

C. ANSI C57 series.

D. IEEE 48 - Test Procedures and Requirements for High-Voltage AC Cable Terminations.

E. NEMA KS1 - Enclosed and Miscellaneous Distribution Equipment Switches (600 Volts Maximum).

F. NEMA SG3 and SG5.

G. NETA ATS - Acceptance Testing Specifications for Electrical Power Distribution Equipment (International Electrical Testing Association).

H. NFPA 70 - National Electrical Code.

I. UL Standards.

J. CEC 2010 – California Electric Code.

1.4 SUBMITTALS FOR REVIEW

A. Section 01 33 00 - Submittals: Procedures for submittals.

B. Shop Drawings: Indicate electrical characteristics and connection requirements, outline dimensions, connection and support points, weight, specified ratings and materials.

C. Submit short circuit and protective device coordination study, including time-current curves, as per Square 26 00 01.

D. Product Data: Provide electrical characteristics and connection requirements, standard model design test, and options.

1.5 SUBMITTALS FOR INFORMATION

A. Section 01 33 00 - Submittals: Submittals for information and catalog cuts.

B. Test Reports: Indicate procedures and results for specified factory and field testing and inspection.

C. Submit manufacturer's installation instructions.

D. Manufacturer's Certificate: Certify that Products meet or exceed specified requirements.

E. Manufacturer's Field Reports: Indicate activities on site, final adjustments and overcurrent protective device coordination curves, adverse findings, and recommendations.

1.6 PROJECT CLOSEOUT SUBMITTALS

A. Section 01 77 00 - Contract Closeout: 01 78 23 - Operation and Maintenance Data: Submittals for project closeout.

B. Include copy of manufacturer's certified drawings in project record documents.

C. Operation Data: Include operating instructions for manually and electrically opening and closing circuit breakers.

D. Maintenance Data: Include maintenance instructions for cleaning methods; cleaning materials recommended; instructions for circuit breaker removal, replacement, testing and adjustment, and lubrication; procedures for sampling and maintaining fluid.

1.7 QUALIFICATIONS

A. Manufacturer: Company specializing in manufacturing the Products specified in this section with minimum ten years documented experience and with service facilities within 100 miles of Project.

B. Testing Agency: Company member of International Electrical Testing Association and specializing in testing products specified in this section with minimum five years documented experience.

C. The manufacture of the circuit breakers shall be the manufacturer of the switchgear assemblies per ANSI 37.20 and UL1558.

D. Switchgear shall be seismically certified per CBC2007.

1.8 REGULATORY REQUIREMENTS

A. Conform to requirements of NFPA 70 and CEC 2007.

1.9 DELIVERY, STORAGE, AND HANDLING

A. Section 01 60 00-Material and Equipment: Transport, handle, store, and protect products.

B. Accept substations on site. Inspect for damage.

C. Protect products from weather and moisture by covering with heavy plastic or canvas and by maintaining heating within enclosure in accordance with manufacturer's instructions.

D. Protect switchgear and transformers from moisture by using appropriate heaters as instructed by the manufacturer.

1.10 FIELD MEASUREMENTS

A. Verify that field measurements are as indicated on shop drawings.

1.11 MAINTENANCE MATERIALS

A. Furnish maintenance materials under provisions of Section 01 77 00.

B. Furnish two each of any special tools required to operate and maintain switchgear.

1.12 EXTRA PRODUCTS

A. Section 01 77 00 - Contract Closeout.

B. Furnish spare fuses - 50% of the quantity installed in equipment.

C. Furnish vacuum circuit breaker lift trucks in each main electrical room – four (4) total.

PART 2 - PRODUCTS

2.1 MANUFACTURERS

A. Square D or equal.

2.2 SINGLE ENDED LOAD CENTER (SECONDARY UNIT SUBSTATION)

A. Description: Single ended secondary unit substation shall consist of high voltage incoming line sections, transformer section, and low voltage switchgear section, as indicated on drawings. The substation shall fully comply with the Standards, and coordinated electrically for protection of circuit and transformer as required by the Standards and Section 26 00 01 of this specification. A rain shield shall be provided on top of the secondary unit substation. Interrupting and short-time ratings of all devices comprising the unit substation shall be adequate for the installation as per requirements of Section 26 00 01.

B. Configuration: As per drawings.

C. CT's, PT's and metering/monitoring devices shall be provided as per requirements of metering and also as indicated on drawings. Accuracy class shall be 0.5, or better.

2.3 SERVICE CONDITIONS

A. Meet requirements for usual indoor service conditions.

B. Maximum Ambient Temperature: 104 degrees F.

2.4 PRIMARY LOAD INTERRUPTER SWITCHES

A. As per drawing and as specified in Section 26 18 00.

B. All PT’s shall be disconnected, grounded and isolated from high voltage when the access door as open.

C. Provide, install and wire a contact closing output for blown fuse detection.

D. Each PT shall have a thermal rating of 500VA at 55 degree C ambient.

2.5 DRY TYPE TRANSFORMER

A. Ratings: 2000/2660 kVA, AA/FA.

B. Primary Voltage: 12.47 kV delta connected.

C. Four Taps: 2 - 2 1/2% above and below normal.

D. Secondary Voltage: 480 volts, wye connected (neutral solidly grounded)

E. Impedance: 5.75 percent.

F. BIL Rating: 95 KV

G. Manufacturer:

1. Square D or equal.

H. Transformers: Ventilated dry type, AA/FA, with temperature controlled fans, 2200C rated insulation system. Transformers as specified are to be included in base bid. In lieu of (VPI) encapsulation with polyester resin transformers, provide alternate bid for furnishing cast epoxy resin dry type transformers.

I. Temperature Rise: 150 degree C rise over a maximum 40 degree C ambient.

J. Other Requirements:

1. Windings shall be of copper.

2. Vacuum pressure impregnation (VPI) encapsulation with polyester resin.

3. The core shall be mounted on neoprene rubber vibration dampeners. It shall be electrically grounded by means of a flexible ground braid.

4. The enclosure shall have removable panels for access to taps and for core and coil inspection.

5. The following shall be provided:

a. Fan cooling package complete with 120V single phase control wiring and winding temperature indicator of digital type. Fans shall be housed in the transformer section.

b. Contacts for alarm and annunciation wired up to terminal block. Separate contacts shall be provided for remote annunciation in case of:

1) Cooling fans being turned on by high temperature

2) Extremely high winding temperature

3) Any other abnormal condition

4) Temperature and fan control shall be Square D Model 98 capable of communicating date and alarms via MODBUS.

5) Connections to metal clad breaker assembly shall be made with copper bus.

c. Copper ground bus

d. Jacking pads, ground pad, diagrammatic name plate, provisions for rolling, ventilation grills and core ground strap of copper

e. Transformer shall be seismically braced for zone 4 applications.

2.6 LOW VOLTAGE EQUIPMENT

A. General: Dead front type, metal enclosed switchgear, designed for a selective system, as per UL 1558, for indoor use, Square D type PZ4, or approved equal, containing all devices and interconnections shown on drawings, this specification, the Standards and also those accessories required for a typical installation such as this Project. The over-all dimensions shall not exceed those shown on drawings. All circuit breakers shall be Square D type NW, or approved equal, and shall be provided with long time, short time, and ground fault protection. The ground fault protection scheme should be appropriate for double ended secondary unit substations and provide full zone selective coordination tripping. The assembly is to be suitable for 600 volts maximum AC service and shall be tested for that voltage class in accordance with applicable NEMA standards. All internal parts energized at bus voltage shall be enclosed in insulating materials. The breakers shall be capable of interrupting a short circuit with a value of 100kA at 480VAC. The switchgear shall be provided with safety shutters. All circuit breakers shall have short-time ratings required for a selective system and Section 26 00 01. Provide key-interlock on circuit breakers as shown on the drawings.

B. Stationary Structure: Each steel unit forming part of the stationary assembly shall be a self-contained housing having individual breaker or instrument compartments and a rear compartment for the buses and outgoing cable connections. Each circuit breaker compartment shall be equipped with primary and secondary contacts, rails, and required instrument current transformers. Each vertical section shall be provided with steel barriers between structures and glastic barriers to isolate the horizontal bus from the cable compartment

C. Busses and Connections: Each circuit shall include the necessary 3 phase bus and connections between the bus and one set of circuit breaker studs. Solderless type terminals on silver-plated copper extensions for the outgoing cables shall be provided on the other set of circuit breaker studs. The busses and connections shall consist of silver-plated copper bar mounted on heavy duty glass polyester supports and having bolted joints. Shipping breaks and provisions for future bus extensions shall have silver-plated bolted connections. Terminal blocks with integral-type barriers shall be provided for secondary circuits. The terminal blocks shall be mounted at the rear of the units, and shall be accessible through a removable cover.

D. Disconnecting Devices: The stationary part of the primary disconnecting devices for each circuit breaker shall consist of a set of silver plated copper contacts extending through a glass polyester insulating base. The line busses and load bus extensions shall be directly connected to them. The corresponding moving contacts shall consist of a set of contact finger clusters suitably fitted to the breaker line clusters suitably fitted to the breaker line and load studs. In the "Connected" position, these contact fingers shall engage the stationary contacts forming a current carrying bridge. The assembly shall provide multiple silver-to-silver high pressure point contacts. High uniform pressure on each finger is to be provided by spring action. The entire assembly shall be full floating in order to provide ample flexibility between the stationary and moving elements. Contact engagement shall be maintained only in the "Connected" position. The secondary disconnecting devices shall consist of floating contact assemblies mounted on the stationary unit and engaging with mating assemblies located on the side of the compartment. The secondary disconnecting devices shall be silver plated to insure permanence of contact. Secondary contact engagement shall be maintained in the "Connected" and "Test" positions.

E. Removable Element and Drawout System: The removable element shall consist of a type NW, or equal, circuit breaker equipped with the necessary disconnecting contacts, wheels, and interlocks for drawout operation. A positive mechanical interlock shall prevent the breaker from being racked in or out while in the closed position either by tripping it or, if it is already tripped, by holding it mechanically trip free. A manual latch shall positively position the removable unit in the "Test" and "Disconnected" positions and provisions for padlocking in all positions shall be made. A limit stop shall be provided in the fully withdrawn position and in this position it shall be possible to rotate the unit 90 degrees for inspection and maintenance. All breakers shall have microprocessor based trip and monitoring devices necessary to protect, coordinate as per Section 26 20 00 and meter the analog quantities indicated in paragraph F below.

F. Microprocessor based accessories for protection, and monitoring.

1. Overcurrent Protection: Each circuit breaker shall be provided with an electronic trip unit having the following features, as a minimum:

a. Trip unit sensing: True RMS

b. Adjustable settings and other features required are:

1) Long delay pick up current and time (I2t response)

2) Short delay pick-up current

3) Short delay: Flat response (for coordination with other circuit breakers with electronic trip devices)

4) Short delay: I2t response (for coordination with thermal magnetic circuit breakers)

5) Zone Selective Interlocking

6) Ground fault pick up and Zone Selective Interlocking

7) Ground fault delay: Flat response (for coordination with other circuit breaker with electronic ground fault trip setting).

a) Trip units shall have metering functions including, but not limited to Amps, Volts, Watts, KwHr, Demand, thermal imaging, VA, VAR, VARh, voltage imbalance in % and PF, equal to Square D Micrologic 6.0P. Trip unit must be capable of communicating 4 wire MODBUS, RTU, RS485.

c. System diagnostic information: cause of trip, and communicating it over MODBUS or MODBUS PLUS network.

2. Metering and Communication

a. For Main Circuit Breakers use Square D CM4000T: As per drawings.

The following shall be provided, as a minimum, to achieve this objective:

For each outgoing circuit breaker in the unit substation, provide one Ethernet gateway EGX400 interface for each side of the double-ended unit substation will be acceptable, if functionally adequate.

7. FACTORY FINISHES

A. As specified in Section 26 13 13.

2.8 SOURCE QUALITY CONTROL

A. Section 01 45 00 – Quality Assurance: Manufacturer quality control.

B. The switchgear shall be completely assembled, wired, adjusted and tested at the factory. After assembly, the complete switchgear shall be tested under simulated service conditions to verify correct wiring & functioning of all devices.

C. Provide factory routine tests as per Standards.

PART 3 - EXECUTION

3.1 EXAMINATION

A. Section 01 31 19 – Coordination and Meetings: Verification of existing conditions prior to beginning work.

B. Verify that support pads furnished under Section 03 30 01 are ready to receive Products.

C. Manufacturer shall include witness testing at factory for 5 representatives of the San Francisco Airport. All travel and expenses shall be included. If travel exceeds 1000 miles from San Francisco, air travel shall be business class.

3.2 INSTALLATION

A. Install in accordance with manufacturer's instructions and Standards.

B. Install substation plumb and level and with each section aligned properly.

C. Make electrical connections between equipment sections using connectors furnished by manufacturer.

D. Tighten all accessible bus connections and mechanical fasteners after placing load centers (secondary unit substation) to manufacturer’s recommended torque value.

3.3 FIELD QUALITY CONTROL

A. Section 01400 - Quality Assurance – 01 45 00 - Starting of Systems: Field inspection and testing.

B. Inspection and test in accordance with NETA ATS as applicable.

END OF SECTION

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