140R3021R0019_A0005_-_KN6A___KN8A_Transformer_Rehabilitation_-_Q_A_0005.pdf

United States Department of the Interior

BUREAU OF RECLAMATION

P.O. Box 61470 Boulder City, NV 89006-1470

LCB-10300 August 3, 2021 1.3.11

VIA ELECTRONIC MAIL ONLY

Subject: 140R3021R0019 Amendment 0005, KN6A and KN8A Transformer Rehabilitation, Questions and Answers

In response to the recent site visit held on July 7, 2021, the following questions were asked by interested parties and responses are provided as follows:

Question 27: Would you please provide pictures of SMIT NYMEGEN transformer top cover?

Answer: There was no access during the site visit. Photos of the top of the transformers were provided in Amendment 0003.

Question 28: Rapid Tank Depressurization is not fully defined. Would the NFPA 850 edition 2020 terminology "Fast Depressurization System" be compliant with the system requested by USBR?

Answer: Provided NFPA 850 lists requirements and recommendations for transformer tank depressurization, then yes, the supplied product should address these items.

Question 29: Is the electrical connection of the alarm contact of Rapid Tank Depressurization in scope of supply? If yes, what is the limit of supply: control cabinet located on transformer or plant control room?

Answer: A control box shall be provided and a minimum of one normally open (N.O.) and one normally closed (N.C.) contact to show status of rapid tank depressurization. To note, the normally open and normally closed contacts shall come directly from the tank depressurization. A separate relay is not allowed for indication as there is a lag and on or both contacts will be used to isolate the transformer.

Question 30: Is there any requirement for support to be placed on existing firewalls?

Answer: No requirement for support on the firewalls. If required, then this needs to be noted in the offer/proposal.

Question 31: Does USBR expect the manufacturer of the Rapid Tank Depressurization to have performed live test on transformer full of oil with similar dimension to the Hoover Dam units and is able to provide test certificate from laboratory?

Answer: Past test data would be beneficial to include in the proposal; however, it is not required.

Question 32: Is USBR considering evaluating the Rapid Tank Depressurization based on any known background history of success upon performance or so? If no, why?

Answer: The Rapid Tank Depressurization is an option in the RFP, and will be evaluated in accordance with Section M.

Question 33: The oil sample information previously provided in Amendment 0003 indicates there is lead in the oil. Is lead abatement to be included in the proposal?

Answer: RFP Attachment 1, Section 2.15, states “Oil that is removed from the transformer will be filtered before being pumped back into the transformer.” Filtering includes removing gases and moisture from the oil. It is not the Government’s intent to have the oil replaced with new or have it abated. In the event the oil has excess amounts of lead than what is stated in the oil samples reported on 8/2/2019, this will be processed as a change order after contract award, as unforeseen site conditions.

If you have any questions regarding responses to the questions above, please contact Perry Harris, Contract Specialist, at pharris@usbr.gov, or the undersigned at aamador@usbr.gov.

Aimee Amador Contracting Officer mailto:pharris@usbr.gov mailto:aamador@usbr.gov