Q&A_-_Wolf_Creek_Station_Services_Responses_112017-Final.pdf

Site Visit Questions

W912P5-17-R-0002 Wolf Creek Station Service Upgrade

Question1: 2.7.2 – Request approval to providing Type K thermocouple instead of RTDs to measure temperature as they provide the same functionality as RTDs. (See Section 26 12

16.10 26 Dry Type Transformer)

Answer 1: Propose as specified in section 2.7.2 of 26 12 16.10 26 specifications.

Question 2: 3.1.2.a – Insulation power factor test is a liquid filled test only. As this is dry type transformer, please confirm test is not required. (See Section 26 12 16.10 26 Dry Type Transformer)

Answer 2: Insulation Power Factor tests are acceptable for dry type transformers over 50Kva.

The transformers supplied under this contract are 2000Kva transformers. Therefore, the Insulation Power Factor test shall be required.

Question 3: 2.2.9.4 – Please confirm fluidized bed epoxy powder coat insulation and PVC boots in lieu of neoprene are acceptable as long as they meet the performance requirements as specified in this clause.

Answer 3: See amended specification 2.2.9.4 Insulation to add or equal.

Question 4: 2.2.10.4 and .5 – Protective metal enclosure and metal conduit for LV wiring are not required per the standards referenced in this section. Can Government advise basis of design for this requirement/or allow exception as long as manufacturer meets the standards.

Answer 4: The basis of the design is to provide shielding for the control wiring. Propose as specified.

Question 5: 2.3.1 – Please advise what is meant by “interchangeable with Eaton”. It is understanding that all breakers in the existing metal clad equipment, including the two Eaton breakers, are being removed and replaced by the new switchgear. To what extent is it required for breakers to be “interchangeable”/what does the Government mean by “interchangeable”? (See Section 26 13 13.10 26 – Metal Clad Switchgear)

Answer 5: This section is referring to the 15KV breakers associated with the station service transformer install, not the 480v breakers. We currently have three phase disconnects being replaced with 15KV breakers. “Interchangeable” means the existing six 15KV Eaton breakers should be usable within the new switchgear provided for the station service transformers.

Question 6: 2.2.8.1.c: Is a pad lockable transparent Breaker cover over each breaker acceptable in lieu of metal plate?

Answer 6: Yes, as long as the transparent plate is bolted down with security screws, be pad lockable, and as durable as a metal plate is acceptable.

Question 7: 2.2.10: SEL does not recommend using fiber optic sensing in LV Switchgear due to false tripping conditions. We recommend to configure SEL 751 relays and optical arc flash detection point sensors in the main breaker compartment of the LV switchgear. Contractor will then coordinate the installation of the relays with the Zone Selective Interlocking Protection System of Mains and Feeders in the switchgear. This approach will provide complete and fast load-side clearing of arcing faults in the switchgear without the risk of nuisance tripping. Please confirm this is acceptable approach.

Answer 7: Not an acceptable approach for the government. Propose as specified.

Question 8: 2.2.11.e Metal Conduits are not required per ANSI/IEEE standards for LV SWITCHGEAR and will therefore add significant cost to provide. What is basis of this design requirement? Will Government accept alternate as long as meets standards as required in this section?

Answer 8: The basis of this design requirement is to provide shielding. Yes, Government will accept an alternate if it meets specifications.

Question 9: 2.2.12.a Is AMP approved equal to Burndy?

Answer 9: As long as individual component specifications are equal.

Question 10: 2.7.2- Our Standard VTs have accuracy/Burden and Thermal Rating values of 0.6w, 1.2x, 150va Thermal which meets IEEE C57.13. Is this acceptable? If not, can Government advise basis manufacturer(s) used as basis of design to help us source and provide in compliance? (See Section 26 23 10.10 26 – 480 Volt Switchgear)

Answer 10: Not acceptable by government. Propose as specified.

Question 11: 2.1.4 Standard is manual shutters. Advise if this paragraph is indicating automatic shutters.

Answer 11: This is indicating shutters that mechanically close when breaker is being withdrawn.

Question 12: 2.1.14 Elapsed Time Meters – The specs ask to provide “as per the existing MCC’s”. Can Government provide information of make and model number of existing units?

Answer 12: The unwatering sump pump elapsed time meters: Redington model 720-6300, 85- 500vac.

Question 13: Can Government confirm if any locations of MCCs have space constraints? (See Section 26 24 19.00 26 – Motor Control Centers)

Answer 13: There are locations that have height, width and depth constraints. These dimensions can be found in the reference drawings.

Question 14: The specs call for replacing feeders from SS switchgear to the U and V panels with options if the conductors are not able to be removed from the existing conduits. The contract drawings indicate the replacement of all the feeders leaving the SS switchgear. Do all feeders need to be replaced and if so what are the options for the remaining feeders if they cannot be removed from the existing conduits? Some of these are 1200 feet long and are not in easily accessible areas."

Answer 14: Feeders shall be replaced in accordance with the plans and specifications. Wolf Creek Power Plant staff has assessed the condition and accessibility of the longer feeders, such as those in the power house pylon, and believe such instances will provide for feasible replacement. In the event the Contractor encounters feeders which they believe cannot be feasibly replaced, the Contractor shall notify the Contracting Officer, after which a decision will be made in accordance with the requirements of the contract technical documents and clauses.