Switchgear. Proprietary Information Page 10 AES IRONWOOD CONTRACT FINAL ISSUE - OCTOBER 30, 1998 -------------------------------------------------------------------------------- o Continuous Current: o Main Breaker: Sized to match transformer o Feeder Breakers: 800 A frame and/or 1600 A, as required o Maximum Voltage: 635 V o Insulation Level: 2.2 kV rms low frequency withstand o Interrupting Current: 65 kA symmetrical The low voltage metal-enclosed switchgear has been engineered to provide safe, reliable, and economic control and protection of low voltage distribution systems up to 600 V. The breakers are UL labeled for use in switchgear. Both the switchgear and circuit breakers are built and tested to applicable NEMA, ANSI, IEEE, UL and CSA standards. AUXILIARY TRANSFORMERS Some plant 480 V auxiliary loads, such as the water treatment MCC's and the cooling tower MCC's, may be fed directly from auxiliary transformers that step down the voltage from 6900 V to 480 V and have a kVA rating compatible with their specific loading. These auxiliary transformers will be dry-type, indoor or oil-filled, outdoor designs, as appropriate. The dry-type, indoor auxiliary transformers are similar to the SUS transformers, except that the low voltage terminations will be suitable for cable exit. The oil-filled, outdoor auxiliary transformer ratings and features are: Outdoor Auxiliary Transformers: o Voltage Ratings: o H Winding: 6900 V, 95 kV BIL, delta connected -------------------------------------------------------------------------------- Proprietary Information Page 11 AES IRONWOOD CONTRACT FINAL ISSUE - OCTOBER 30, 1998 --------------------------------------------------------------------------------
Switchgear. This section covers the engineering, design, manufacture, installation and testing of 4160 volt and 480 volt switchgear as required for the project. The 4160 volt switchgear is to deliver power to the 4000 volt motor and 480 volt auxiliary power system. The 480 volt switchgear shall deliver power to large 460 volt motors and 480 volt motor control centers. All equipment furnished shall conform to applicable standards of IEEE, NEMA, ANSI and OSHA. The switchgear shall be UL-labeled. The switchgear shall be designed for use on 4160 volt or 480 volt, three phase, 60 hertz, three wire, resistance grounded systems. Grounding may be provided through a grounding transformer. Switchgear shall be housed in suitable enclosures for indoor service and of the metal-clad, drawout type. Switchgear may be located in weather tight, walk-through, outdoor enclosures. The arrangement of breakers and starters shall be determined by the Contractor. All switchgear shall have interrupting and bus bracing ratings that are adequate to withstand the worst case fault conditions. The spaces above switchgear and motor control centers shall be kept free of piping to avoid contaminants from entering the housings in the event of leaks. At least one equipped spare breaker of maximum rating shall be provided for each 4160V switchgear lineup, and at least one spare feeder breaker and one equipped spare shall be provided for each 480V SUS lineup. -------------------------------------------------------------------------------- EPC - Exhibit B -------------------- TENASKA GEORGIA GENERATION PROJECT Page 91 of 132 -------------------------------------------------------------------------------- Sufficient space shall be provided to allow easy withdrawal of breakers for operation or maintenance. Doors for equipment rooms shall be sized for the largest piece of equipment to pass through. All multiple breaker metal-clad switchgear assemblies shall consist of vertical sections mounted side-by-side and connected mechanically and electrically together. Each vertical section shall consist of separate compartments where all live parts are completely enclosed within grounded metal barriers. The switchgear assembly shall be suitable for bolting to the switchgear room floor. Each vertical section shall be of rigid self-supporting steel of welded construction. Access to high voltage equipment compartments shall be provided by bolted-on metal covers. Hinged panels shall enclose the front of the vertical secti...
Switchgear. All switchgear is inspected and maintained in accordance with OEM specifications which are obtained from the Duvha P/S library. In some instances, the Contractor will be required to execute maintenance with PTM, Eskom protestation system maintenance contractor. The Contractor shall execute the following maintenance: Remove all panel covers and clean board internally Clean and inspect all busbars, links, cable connections Clean and inspect VT's Reposition cable number tags if required Check wear-gap Replace vermiculite where necessary CT inspection and cleaning Replace broken plastic screws on panel covers Pressure test Vacuum bottles Insulation test Vacuum bottles Ductor test Vacuum breakers Links to be function checked Clean and inspect all breakers Lubricate breakers and function checks
Switchgear motor control centres and circuit breaker panels Ensure that all switchgears, motor control centres and circuit breaker panels are in a good condition. Timely intervention with temporary measures within 4 hours, permanent restoration within 7 days, depending on nature and intensity of work required as decided by the Concessioning Authority and any faulty equipment should be replaced with the same specification equipment.
Switchgear g. Control and monitoring systems
Switchgear. The switchgear buses shall be connected in a double-ended arrangement with a normally open tie breaker. Low‑voltage switchgear shall have a copper bus. The low‑voltage switchgear breakers shall be electrically operated, draw out type. The switchgear will be located indoors or in prefabricated electrical equipment enclosures. Control of incoming low‑voltage switchgear breakers and the bus tie breaker shall be provided at the switchgear. All 480‑V main and tie breakers shall typically be operated by remote control from the DCS CRT console. All feeder breakers to MCCs and distribution panels shall also be electrically operated. The protective system shall include a communication interface to the plant DCS for system monitoring. Ring-type current transformers shall be furnished for instrument transformers. The thermal and mechanical ratings of the current transformers shall be coordinated with the circuit breakers. Their accuracy rating shall be equal or higher than ANSI standard requirements. The standard location for the current transformers on the bus side and line side of the breaker units shall be front accessible to permit adding or changing transformers without removing high‑voltage insulation connections.
Switchgear. All types of switchgear, up to and including 11 kV (SF-6, oil, vacuum and airblast installations including pneumatic hydraulic or spring devices). Switchgear protection equipment. Transformers: Up to 100 MVA. Valves: Total refurbishment of all types of valves, up to 4,5m diameter. Dam equipment/structures: Sluice gates, stop logs, screens, hydraulic equipment, etc.
Switchgear. The switchgear installation shall be assessed by the Contractor to assess the phase droppers which shall need to be modified from a 2 phase supply to a 3 phase supply for each HFPS switchgear feeder. The Contractor shall then submit for the approval of the Employer an approved methodology for modifying the switchgear, the Contractor shall after approval, modify, test and commission the switchgear to prove functionality of the precipitator boards and buckets. Eskom will supply the Contractor with the following drawings at tender stage (see section 9): General assembly drawings Cable schedules Switchgear schedules Component list/ schedule for the applicable bucket. All modifications shall be performed in accordance with 240-56227516 and other applicable standards. The Contractor shall ensure that all equipment used to modify the switchgear feeder buckets shall be approved by the OEM and shall not compromise the switchgear type test performance. Part numbers are to be confirmed prior to installation. The Contractor shall ensure that conductors installed to achieve the required three phase operation of each feeder bucket shall be rated to withstand the board/switchgear fault current for a minimum of the one (1) second as per the board design. The Contractor is also required to ensure that each of the phases coming from the board down comers are insulated using heat shrinking with a minimum voltage rating of 1000 V. The Contractor shall ensure that switchgear conforms to the insulation coordination as specified in 240-56227516 and shall be reviewed by the client before implementation. The Contractor shall ensure that the mechanical integrity/ sturdiness of the conductor supports and or the insulators used for supporting each phase as it connects to the isolator is in no way compromised. The Contractor shall carry out Ductor testing on each of the modified circuits prior to commissioning of the board supply to demonstrate the electrical integrity of the electrical connections done, insulation resistance testing shall also be performed and all tests shall be required to pass the minimum requirements as set out in the boards SAT documentation which shall be approved by the Employer.
Switchgear a. Inspect for damage and missing parts, alignment, X clearance of moving parts, etc.
Switchgear. 3.5.1.1The SF6 RMU shall be Sealed for life, the enclosure shall meet the “sealed pressure system” criteria in accordance with IEC: 298 (a system for which no handling of gas is required throughout service life of approximate 25 years.) There shall be no requirement to „top up‟ the SF6 gas. In addition, manufacturer shall confirm that maximum leakage rate is lower than 0.1% per year. It shall provide full insulation, making the switchgear insensitive to the environment. Thus assembled, the active parts of the switchgear unit shall be maintenance free.
