A22_W912P919R0044_Amend_5.pdf

W81C8X91150348

AMENDMENT OF SOLICITATION/MODIFICATION OF CONTRACT

Except as provided herein, all terms and conditions of the document referenced in Item 9A or 10A, as heretofore changed, remains unchanged and in full force and effect.

15A. NAME AND TITLE OF SIGNER (Type or print)

30-105-04EXCEPTION TO SF 30

APPROVED BY OIRM 11-84

STANDARD FORM 30 (Rev. 10-83) Prescribed by GSA

FAR (48 CFR) 53.243

The purpose of this amendment is:

1. See Page 2 for changes pertaining to General and Technical requirements.

2. Post the last set of questions and answ ers for this requirement.

3. Bid Item 0018 is changed.

4. Move Factor 3 from Volume 1 to Volume 2

5. Attach is the Revised specs.

There are no other changes.

1. CONTRACT ID CODE PAGE OF PAGES

J 1 14

16A. NAME AND TITLE OF CONTRACTING OFFICER (Type or print)

16C. DATE SIGNED

BY 03-Sep-2019

16B. UNITED STATES OF AMERICA15C. DATE SIGNED15B. CONTRACTOR/OFFEROR

(Signature of Contracting Officer)(Signature of person authorized to sign)

8. NAME AND ADDRESS OF CONTRACTOR (No., Street, County, State and Zip Code) X W912P919R0044

X 9B. DATED (SEE ITEM 11)

25-Jul-2019

10B. DATED (SEE ITEM 13)

9A. AMENDMENT OF SOLICITATION NO.

11. THIS ITEM ONLY APPLIES TO AMENDMENTS OF SOLICITATIONS

X The above numbered solicitation is amended as set forth in Item 14. The hour and date specified for receipt of Offer is extended, X is not extended.

Offer must acknowledge receipt of this amendment prior to the hour and date specified in the solicitation or as amended by one of the following methods:

(a) By completing Items 8 and 15, and returning 1 copies of the amendment; (b) By acknowledging receipt of this amendment on each copy of the offer submitted;

or (c) By separate letter or telegram which includes a reference to the solicitation and amendment numbers. FAILURE OF YOUR ACKNOWLEDGMENT TO BE RECEIVED AT THE PLACE DESIGNATED FOR THE RECEIPT OF OFFERS PRIOR TO THE HOUR AND DATE SPECIFIED MAY RESULT IN

REJECTION OF YOUR OFFER. If by virtue of this amendment you desire to change an offer already submitted, such change may be made by telegram or letter, provided each telegram or letter makes reference to the solicitation and this amendment, and is received prior to the opening hour and date specified.

12. ACCOUNTING AND APPROPRIATION DATA (If required)

13. THIS ITEM APPLIES ONLY TO MODIFICATIONS OF CONTRACTS/ORDERS.

IT MODIFIES THE CONTRACT/ORDER NO. AS DESCRIBED IN ITEM 14.

A. THIS CHANGE ORDER IS ISSUED PURSUANT TO: (Specify authority) THE CHANGES SET FORTH IN ITEM 14 ARE MADE IN THE

CONTRACT ORDER NO. IN ITEM 10A.

B. THE ABOVE NUMBERED CONTRACT/ORDER IS MODIFIED TO REFLECT THE ADMINISTRATIVE CHANGES (such as changes in paying office, appropriation date, etc.) SET FORTH IN ITEM 14, PURSUANT TO THE AUTHORITY OF FAR 43.103(B).

C. THIS SUPPLEMENTAL AGREEMENT IS ENTERED INTO PURSUANT TO AUTHORITY OF:

D. OTHER (Specify type of modification and authority)

E. IMPORTANT: Contractor is not, is required to sign this document and return copies to the issuing office.

14. DESCRIPTION OF AMENDMENT/MODIFICATION (Organized by UCF section headings, including solicitation/contract subject matter where feasible.)

10A. MOD. OF CONTRACT/ORDER NO.

2. AMENDMENT/MODIFICATION NO. 5. PROJECT NO.(If applicable)

6. ISSUED BY

3. EFFECTIVE DATE

03-Sep-2019

CODE

CONTRACTING DIVISION

US ARMY ENGR DIST ST LOUIS

1222 SPRUCE STREET, RM 4.207

ST LOUIS MO 63103-2833

W912P9 7. ADMINISTERED BY (If other than item 6)

4. REQUISITION/PURCHASE REQ. NO.

CODE

See Item 6

FACILITY CODECODE

EMAIL:TEL:

W912P919R0044

SECTION SF 30 BLOCK 14 CONTINUATION PAGE

SUMMARY OF CHANGES

SECTION SF 30 - BLOCK 14 CONTINUATION PAGE (SF 30)

The following have been added by full text:

CHANGES TO GENERAL & TECHNICAL

GENERAL REQUIREMENTS

SECTION 00 00 10 – Delete this section and replace it with the attached, like-numbered section, which includes changes to Bid Item 0018.

SECTION 00 08 00 – Delete this section and replace it with the attached, like-numbered section, which includes changes to paragraph 1.19(23).

SECTION 01 22 00 – Delete this section and replace it with the attached, like-numbered section, which includes changes to paragraph 1.3 CLIN 0018.

TECHNICAL REQUIREMENTS

SECTION 03 60 00.01 26 – Delete this section and replace it with the attached, like-numbered section, which includes changes to paragraphs 1.4, 2.6, 3.5.3, 3.6, 3.7 and 3.8.

SECTION 13 48 00.00 26 – Delete this section and replace it with the attached, like-numbered section, which includes changes to paragraphs 1.4.2 and 1.4.3.

SECTION 26 25 00.00 26 – Delete this section and replace it with the attached, like-numbered section, which includes changes to paragraph 2.1.1,

2.1.2 and 2.1.3.

SECTION 48 19 26.00 26 – Delete this section and replace it with the attached, like-numbered section, which includes changes to paragraph 2.4.1, 2.4.3, 2.5.1.1 Table, 2.9.3, 3.3.3.2, and 3.3.3.4.

CONTRACTOR QUESTIONS

See below questions with Government responses.

QUESTIONS & ANSWERS NO. 4

Clarence Cannon Power Plant Excitation System Replacement

Pre-proposal Questions 15 Aug 2019

Answers to these questions have resulted in a revised contract specification.

SECTION 26 25 00.00 26

1. 2.1.10 Common steel sheet housing is specified for the bus ducts. Would a 0.125” aluminum sheet bus duct enclosure be acceptable as it protects better against corrosion and magnetic interference? The drawings mention that the existing bus duct has an aluminum enclosure.

As shown in the Abbott Power Corporation reference drawing numbers 7762‐1, ‐2, and ‐3, the bus and bus duct housing are aluminum. The specification section has been amended to address these materials.

SECTION 48 19 26.00 26

2. 2.5.1.1 There is conflicting information in terms of the short‐term field current rating. Should we assume that

1,350Adc for 30s is correct instead of 1,244.5Adc for 10s.

Yes, 1,350 Adc for 30s is correct.

3. 3.3.3.2.c Please clarify which high voltage fuse compartment this refers to.

The removal of a high voltage fuse compartment is not required as a part of this contract.

4. 3.3.3.2.g Please clarify if there is an existing shaft ground brush assembly to be removed as we were not able to see an assembly during the site visit.

There is no existing shaft ground.

5. 3.3.3.4 There is a 2’x1’ floor cut‐out for each existing exciter and some core drilled holes. Please clarify the government requirements for retiring larger floor penetrations as section 03 60 01.00 26 is primarily focused on concrete removal and minor floor repair. To what extent does the floor need to be reinforced after filling etc?

Specification Section 03 60 01.00 26 has been amended to reflect the repair of these locations.

Clarence Cannon Power Plant Excitation System Replacement

Pre-proposal Questions 19 Aug 2019

1. Related to the answer of question 5 in the Q&A supplied in Amendment 3, is this armature circuit installation on the rotating exciter? Previously, it was indicated that the ACM was for the wiring from the exciter cabinet to the control room cabinet. Are these cables on the exciters themselves or from the excitation cabinet to the exciter?

The insulation tested and documented in the previously provided report under Amendment 4 are on the cables from the excitation cabinet to the exciter. See contract drawing ED605.

Wiring internal to the exciter cabinet has similar insulation and is assumed to be an asbestos containing material.

2. Referring to question 8 in the Q&A supplied in Amendment 3, If the existing rotating exciter field poles need to be removed, we assume that all poles shall be removed in order to not create an imbalance on the machine.

As the poles are installed on the stationary side of the existing rotating exciter and the existing rotating exciter will no longer be in use following this contract, an imbalance will not be created by removing one or any number of exciter poles.

3. Drawing E‐101 shows the connections of a new non‐segregated metal enclosed AC bus between the existing

13.8 kV switchgear and PPT. Information on the existing switchgear fabrication has not been shared, so it is not possible to define the changes required to the switchgear assembly in order to accommodate the new AC bus. Therefore, could you please share the switchgear fabrication drawings enabling us to define this part of the scope? In case the drawings are not shared, we will assume then that the switchgear is readily suitable for the new metal enclosed bus by adding equipment interface enclosure without any internal changes to the switchgear assembly. Please provide drawings or confirm acceptance of this approach.

Refer to the answer of Question 6 posted under Amendment 3.

4. Specification 00 08 00.00 26 Section 1.19.23 (pdf Page 12 of 241) requires vectorizing (raster file to CADD) of

50 drawings. These drawings have not been shared so extent of drafting is not clear. We will consider a fixed number of hours per drawing assuming that these are schematics and simple general arrangement drawings.

In case these drawings involve an extensive drafting exercise, we will discuss and adjust the budget. Please confirm acceptance of this approach.

The extent of the drawing vectorization is unknown prior to contract award. As the Contractor proceeds with shop drawing development, the need to revise existing reference drawings may become apparent.

The bid schedule and Sections 00 08 00 and 01 22 00 have been revised to indicate a unit of “hour” in lieu of “each.” The optional bid item may be exercised to provide up to 400 hours of drawing vectorization.

5. Specification 13 48 00.00 26 Section 1.4.2 (pdf Page 120 of 241) requires that equipment restraints be designed “in accordance with the provisions in IEEE 693 Annex D, or Section 13.3 of ASCE 7 whichever produces the more adverse seismic effects” and spectral acceleration as well as seismic qualification are given for high seismic zone. Nevertheless, according to the USGS seismic zone map, the Clarence Cannon Power Plant is located in a low seismic zone. Therefore, could you please clarify whether there is a specific reason why the Corps wants to have the restraints designed for high seismic zone? Since the Clarence Cannon Power Plant is in a low seismic zone, would it be acceptable to design the restraints for the corresponding seismic zone (meaning low)?

Section 13 48 00.00 26 has been amended to reduce the Sds and seismic qualification to "moderate" levels. However, it will not be acceptable to design equipment and restraint to "low" seismic qualification levels.

6. In first page of solicitation W912P919R0044, it is said that we will have 532 calendar days to complete the project after receiving the “notice to proceed”. However, in page 51 of the same document, section 52.211‐10 COMMENCEMENT, PROSECUTION, AND COMPLETION OF WORK (APR 1984) ‐ ALTERNATE I (APR 1984), it is said that we have 548 calendar days to complete the entire work after receiving the “notice to proceed”.

Please clarify which one is the real total amount of days that we have to complete the entire work.

The project will be completed in 532 calendar days after receiving notice to proceed.

7. In first page of solicitation W912P919R0044, it is said that we will have 532 calendar days to complete the project after receiving the “notice to proceed”. However, in page 51 of the same document, section 52.211‐12 LIQUIDATED DAMAGES‐‐CONSTRUCTION (SEP 2000), it is said that “Liquidated Damages will be assessed to the contractor in the amount of $5,200.00 daily when the power plant is unable to generate power from 15 June through 15 September 2020, and any time after 15 January 2021”. If we assume that an order will be awarded on 30 September 2019, and that the “notice to proceed” will be received 10 days after (meaning 10 October 2019), then the 15 January 2021 is only 463 days away from the date on which we would be receiving the notice to proceed; Therefore, there is an inconsistency between the allowed amount of time for completion of the project and the date on which daily liquidated damages are to be applied. Please confirm our understanding and if needed, clarify this clause or otherwise modify it for consistency.

The contract duration provides additional time for onsite activities not critical to the operation of the new exciters and contract closeout. 15 Jan 2021 is a date set by the Southwest Power Administration where both units must be returned to service. This provides a 120‐day installation window from 15 Sep 2020 to permit the installation of both exciters back‐to‐back.

8. Specification 48 19 26.00 26 Section 1.1.4 (pdf Page 191 of 241) includes some electrical characteristics of both generators, but some key information is still missing such as the quadrature reactance, the armature reactance or the sub‐transient and armature time constants, just to mention a few. This information is very important to size properly certain components such as the discharging circuit. Can the Corps please provide copies of each of the machine’s data from the actual generator’s OEM manuals?

Please find the files “Unit 1 Test Report.pdf” and “Unit 2 Test Report.pdf” available as a separate download.

9. Specification 48 19 26.00 26 Section 2.5.1.1 (pdf Page 199 of 241) mentions that “Excitation System Current Output 900 Adc Continuous minimum; 1350 Adc for 30 seconds; Ceiling Current Requirement 1244.5 Adc for 10 seconds”. However, the requirement of 1350 Adc for 30 seconds is quite atypical and we rather understand that this requirement corresponds to the Ceiling Current requirement instead of the mentioned 1244.5 Adc for 10 seconds. Please clarify and confirm the correct nominal output current and ceiling currents.

Please see the answer to Question 2 from 15 Aug 2019 in this same amendment.

10. Specification 26 25 00.00 26 Section 2.1.8 (pdf Page 182 of 241) Are the silver plated connections related only to the external buses or do they include the internal buses as well (meaning, inside the excitation system)?

In accordance with Specification 26 25 00.00 26, paragraph 2.1.5.1, metal‐enclosed bus contact surfaces shall be silver‐plated. In accordance with Specification 26 25 00.00 26, paragraph 2.1.4.2, contact surfaces of bonding attachment terminals shall be silver‐plated. In accordance with Specification 26 25 00.00 26, paragraph 2.1.5.4, non‐segregated phase bus joints and conductor terminals shall be silver‐plated. In accordance with Section 48 19 26.00 26, paragraph 2.5.2, excitation system internal buswork connections shall be silver‐plated. In accordance with Specification 48 19 26.00 26, paragraph 2.5.3, internal ground bus bar splice contacts shall be silver‐plated.

11. Specification 48 19 26.00 26 Section 2.4.3 (pdf Page 198 of 241) mentions that “three new current limiting fuses (CLFs) and holders shall be provided in the primary chamber of each potential power transformer (PPT).

Submit Fuse Ratings for approval. The BIL rating for the fuse holders shall be 110kV. The fault current available at the generator terminals is 40.675 kA, symmetrical. Provide a non‐load breaking three pole 15 kVdc Disconnect Switch on the line side of the CLFs”. A switch with a 110 kV BIL would be a rather big component and, given the fact that the footprint allowed for the transformer is limited, we are wondering how it can be housed in the upper part of an enclosure. Is there a possibility to allow more room for the disconnect switch by increasing the allowed footprint of the PPT? And if yes, how much can be allowed?

See the answer to Question 12 below.

12. Specification 48 19 26.00 26 Section 2.4.3 (pdf Page 198 of 241) mentions that “three new current limiting fuses (CLFs) and holders shall be provided in the primary chamber of each potential power transformer (PPT).

Submit Fuse Ratings for approval. The BIL rating for the fuse holders shall be 110kV. The fault current available at the generator terminals is 40.675 kA, symmetrical. Provide a non‐load breaking three pole 15 kVdc Disconnect Switch on the line side of the CLFs”. For a disconnect switch with fuse holders rated 15kV, the standard BIL level is 95kV instead of 110kV. Please confirm that the 95kV BIL level is acceptable since 110kV does not seem to be available in the market.

Section 48 19 26.00 26 has been amended to reduce the BIL to 95kV.

13. Factor 2 Past Performance, Will the Corps please consider accepting completed CPAR reports submitted with the proposal (for projects that meet the project requirements) in lieu of a PPQ form?

No, please submit PPQ Form as part of your proposal.

14. 00 21 13 ‐ Instructions to Bidders, In the instructions to bidders under REQUIREMENT FOR SEPARATE TECHNICAL AND PRICE PROPOSALS it states "(5) Do not include any dollar amounts in the Technical Proposal that are taken from the Price Proposal. Vol 1 Technical" However, FACTOR 3 – Small Business Participation Plan Exhibit A pg. 30 of 109 "(b) Submit the total combined dollar value and percentage of work to be performed by both large and small businesses ..." Question: The example shows that when combined the total value of the project would be exposed to the evaluator, as such would the Corps consider moving Tab 3 to Vol 2 Price Proposal to prevent any dollar values from being exposed? Alternatively, a plan containing redacted dollar values could remain with percentages shown and an unredacted version would be included in Vol 2.

Yes, please move Factor 3 (Small Business Participation Plan Exhibit A) from Volume 1 to Factor 3 (Small Business Participation Plan Exhibit A) Vol 2.

15. Subcontracting Plan Large business, If a Commercial Plan is accepted do we still need to break out the small business concerns by category for this specific proposal?

Yes, you still need to break out the small business concerns by category for this proposal.

16. 252.215‐7009, PROPOSAL ADEQUACY CHECKLIST (JAN 2014), Given this solicitation is for a full and open, best value tradeoff continuum, firm‐fixed price contract does the PROPOSAL ADEQUACY CHECKLIST apply, or was this included in error?

Yes, the Proposal Adequacy Checklist apply.

17. Confirm if this is a taxable project. Provide tax exempt forms as applicable

Yes, this is a taxable project. The tax exempt forms will be sent to the contract awardee.

SECTION 48 19 26.00 26

18. Para. 1.4.4, Could the 2000:5 current transformer (requested to be removed on B phase) be left in place as a spare current transformer and CTs secondary terminals be shorted for future use.

No, the CT shall be removed and turned over to the Government as required in the contract documents.

19. Para. 1.4.4, Can split core current transformers be utilized for the new installation.

In accordance with Specification 48 19 26.00 26, paragraph 2.11.1, supplied CTs are to be the bushing type.

20. Para. 3.3.7, Para. 3.3.4 Collector Ring Assembly Inspection calls for an inspection of the equipment while 3.3.7 Collector Ring Refurbishment calls for complete repair. Which is correct?

Both features of work (and thereby paragraphs) are valid for this contract. The inspection is to be performed prior to any refurbishment and is intended to inform the degree of refurbishment required.

21. Para. 3.3.7, Please provide existing inspection reports of this equipment and service / inspection intervals.

In accordance with Specification 48 19 26.00 26, paragraph 3.3.4, the Contractor is to perform an inspection of the collector ring prior to refurbishment. For bidding purposes, assume manufacturer recommended maintenance or collector ring condition observed during bidder site walk.

22. Para. 3.3.7, Is it possible to provide an inspection proposal only as specified. Once complete the information can be reviewed for refurbishment options. Therefore line 0007 ("Refurbish existing collector rings (SECTION 48 19 26.00 26)") would not be quoted. The inspection cost would be included under line 0006 ("Furnish and install new brush riggings, brushes, and brush holders (SECTION 48 19 26.00 26)")

The Contractor shall both inspect and refurbish the collector ring assembly, as specified in paragraphs

3.3.4 and 3.3.7 of Section 48 19 26.00 26, respectively.

Specification 01 22 00, paragraph 1.1, work not specifically assigned a CLIN is considered incidental to the CLINs listed. The collector ring inspection is considered incidental to the collector ring refurbishment.

Section 03.60.01.00.26

23. Please provide a description of your expectation of completed concrete patch work once existing exciters are removed.

Blockouts shall be sealed using a grouted, galvanized plate and holes shall be grouted. The specification has been amended to address the concrete patching requirements.

24. Should the existing holes be grouted (no future use) or plated (for future use) Smaller holes beneath the exciter cubicles shall be grouted. The specification has been amended to address the concrete patching requirements.

25. Does the floor need to be surfaced, epoxy coated or painted.

The specification has been amended to address the concrete patching requirements.

Existing customer drawings

26. Existing customer drawings, Please detail the accessibility of existing drawings, current formats, available electronically.

Upon contract award and as shop drawing development progresses, it may be determined that revision of existing shop drawings are necessary to create a thorough as‐built drawing set. The existing shop drawings may exist as a TIF image or paper format. The Government will furnish any drawing to the Contractor in a TIF format.

27. Existing customer drawings, Are existing drawings available in an editable digital vector format such as AutoCAD or MicroStation

The “Phoenix Power System” drawings furnished under the reference drawings are available as a Microstation .dgn file and can be provided to the successful bidder.

28. Existing customer drawings, Please confirm if detail drawings are accurate and up to date within reason including all field revisions.

The Government believes the drawings to be accurate within reason.

29. Existing customer drawings, Confirm drawings are not scanned copies of redlines.

Plant personnel do document changes on paper copies of the existing shop drawings, however the Government cannot confirm if any of the drawings determined to be vectorized contain redlines.

30. Existing customer drawings, Please confirm the drawings do not include imbedded files such as pdf. Jpeg or any other raster file.

Existing customer drawings are available in several formats such as paper, TIF, or Microstation. Electronic formats do not include embedded PDFs or image files.

31. Existing customer drawings, Please confirm all associated files such as borders, title blocks, are included or provided

Any drawings provided in a CAD format (Microstation) will include the border, titleblocks, etc. For the “Phoenix Power Systems” drawings discussed above, all drawings elements are in a single file.

32. Regarding Factor 1 – Technical under subfactor 1B – Technical Data and Approach, we are asked to provide letters of commitment from each subcontractor that we propose to use for design, manufacture, or installation. As this project has many aspects, we have several subcontractors that we propose to work with and therefore many letters of commitment to include. Is it acceptable to the Corps if we added these letters as an appendix to the proposal, as opposed to part of the proposal itself and its page count?

Yes, it is acceptable to the Corps to add the letters of commitment as an appendix to the proposal. The appendix will not be included in the page count.

The following have been modified:

QUESTIONS & ANSWERS NO. 3

Questions and Answers No. 3 Pre-proposal Questions 15 Aug 2019

*Closing Date is extended till 20 September 2019 at 10AM

CST.*

Please Note: Below are questions received prior to 15 Aug 2019. Unanswered questions will be addressed with revised specifications in a forthcoming amendment.

SECTION 00 08 00

Question 1: 1.19.4 Please clarify the significance of the January 15th completion date. If the contract award is made say September 30th, 2019, the contract completion date would extend beyond January 15th, 2021 as the performance period is listed as 532 calendar days from Notice To Proceed. Is the date related to the maximum 60 days per unit outage window and the restricted outage window June 15th ‐ September 15th? Is it possible to extend the Jan 15th date to February 28th and increase the outage window for the first unit, which typically takes longer time than the 2nd unit?

Answer 1: Please find additional information in question 4 answered in Amendment 3.

The contract duration includes additional time beyond 15 Jan 2021 to provide for any onsite work not critical to the function of the digital exciters and contract closeout activities.

The 15 Jan date has been coordinated with the Southwest Power Administration (SWPA) and it cannot be extended. SWPA typically restricts plant outages from 15 Dec through 15 Mar, but has delayed this restriction to provide the 120‐day installation window and permit back‐to‐back installation of both exciters.

2. 1.19.23 Please clarify if the 50 reference drawings in raster format means that they are scanned drawings

(.TIFF, .PDF format etc.) and that the Contractor needs to convert of re‐draw the drawings into Microstation (.DNG format)? Also, do the 50 drawings include drawings for both units or are there 50 drawings per unit?

Answer 2: The reference drawings are in a TIFF format.

Per the bid schedule, it is 50 drawings total.

3. 1.19.24 Please clarify how many .xls sheets of conduit/cable schedule that are required to be updated.

Answer 3: Drawings ED604 and E‐605 identify the cables to be demolished and installed as part of the contract. These cables schedules should be indicative of the amount of effort needed to update the spreadsheet.

SECTION 02 82 14

4. 1.1 Is there a previous report available that identifies the location of any Asbestos Contacting Materials (ACM)? Is the ACM only applicable to the external cabling to the existing exciter cabinet, or does it also include internal wiring and/or components inside the existing exciter ?

Answer 4: See the answer to Question 5 posted under Amendment 3.

The external cabling for the field and armature circuits from the exciter and regulator are known to be ACM. It is believed wiring internal to the exciter/regulator is also an ACM.

SECTION 25 05 11.00 28

5. 1.8 Please confirm that HMI panels (paragraph 2.7.3 in SECTION 48 19 26.00 26) are required to operate with an Operating System that is currently supported by Microsoft, such as, Windows 10. We assume that HMI panels operating with Windows XP or older versions operating systems that are not supported by Microsoft anymore would not be acceptable since security patches would not be up to date. Please confirm.

Answer 5: The requirements of paragraph 1.8 are applicable to personal computers and network servers.

They do not apply to an embedded operating system for an HMI required in paragraph 2.7.3 of Section 48 19 26.00 26.

SECTION 26 25 00.00 26

6. 2.1.5 We understand that seismic calculations are required for the bus duct structure in order to select suitable anchors. Please confirm.

Answer 6: In accordance with Section 13 48 00.00 26, paragraphs 1.3, 1.6, and 3.4, seismic calculations are required for bus duct. Concrete anchor testing is required for all concrete anchors, including those used to in seismic support structures of bus duct.

SECTION 48 19 26.00 26

7. 1.1.4 Given the fact that unit 2 can operate as both generator and motor, should the proposed system have the ability to switch to separate AVR settings, limiters etc, based on a digital input indicating if the unit will operate as a generator or a motor?

Answer 7: In accordance with Section 48 19 26.00 26, paragraph 3.3.8.3, the system shall be capable of starting and operating in pump mode. The specific implementation of this feature is left up to the Contractor, but shall still be subject to the requirements of the specification.

8. 1.1.5 Please clarify if the five (5) year warranty will start at the acceptance for each unit, or at the acceptance of the overall contract.

Answer 8: The warranty shall start upon acceptance of the unit by the Government.

9. 1.4.3 What is the available spare capacity of the 125Vdc panel that can be used for the new field flashing circuits? Is there space in the panel for one field flashing breaker per unit, 60Adc each?

Answer 9: Per the referenced specification paragraph, the existing circuits are rated at 30A. If a larger source is required, the Contractor shall provide new breakers. The existing panelboard make and model has been provided in the same paragraph.

10. 1.4.4 Please clarify if it is the Government's or the Contractor's responsibility to install three (3) new CTs per unit.

Answer 10: The Contractor shall install three new CTs per the specifications and drawing E‐604.

11. 1.4.6 Please clarify if the Contractor is required to install an Ethernet cable from each exciter to the control room for future SCADA interface?

Answer 11: Installation of Ethernet for future use is not required.

12. 2.1 The ambient design temperature is stated as 40 degrees C. Please confirm if this is correct, considering the location of the power plant, where outside temperature can reach above 40 degrees C and power plant temperatures may reach a few degrees higher.

Answer 12: The ambient design temperature of 40 degrees C for the plant floor is correct.

13. 2.4.4 There is no requirement for space heaters / thermostat for the PPT enclosure. We suggest that this requirement is added to prevent moisture build‐up.

Answer 13: If the Contractor desires, space heaters and thermostats maybe included in the PPT enclosure, but this is not a requirement of the contract.

14. 2.4.6 We understand that the requirement is to wire a temperature alarm contact, a temperature trip contact and a 4‐20mA PPT temperature signal to the excitation controller and that the information should be displayed on the HMI panel and be available on MODBUS. Please confirm.

Answer 14: Internal wiring and communication between the PPT and the exciter cubicle is at the discretion of the Contractor within the confines of the specification. Modbus is to be used for communication external to the excitation system.

15. 2.5.2 Please confirm if fully tin‐plated copper bus bars are acceptable vs bare copper bus bars with silver‐ plated connections. Copper bus bars with complete tin‐plating reduces the risk of oxidation of the copper surface over time.

Answer 15: Tin‐plated copper bus bar is acceptable, but not required for this contract. However, silver plated connections are required in accordance with Section 48 19 26.00 26, paragraph 2.5.2.

16. 2.5.9.2 For clarification, we understand that each six‐pulse rectifier bridge shall have it’s own independent redundant cooling fans. A common set of redundant fans serving multiple rectifier bridges would not meet this requirement. Please confirm.

Answer 16: In accordance with Section 48 19 00.00 26, paragraph 2.5.9.2, rectifier assembly cooling shall consist two sets of fans for each rectifier assembly. The fan sets are each to be suitably sized to cool the rectifier assembly (redundant fan sets).

17. 2.6.1 With the requirement: Provide two fully independent and identical control channels, we understand that either control channel shall be able to control either rectifier bridge. Hence, a control channel should not be dedicated to a particular rectifier. Please confirm.

Answer 17: The contract does not specify, therefore either configuration is acceptable.

18. 2.7.3 With the requirement “Provide an additional user‐selectable display on the HMI which clearly displays configuration parameters (to include protective settings and tuning parameters at a minimum” we understand that the user shall be able to view/change these settings directly from the HMI without having the need to connect a separate laptop. Please confirm.

Answer 18: The contract does not specify, therefore either configuration is acceptable.

19. 2.9.3 The specification allows for either copper or aluminum conductors, while section 26 25 00.00 26, specify only copper conductors. Please confirm which requirement that is correct.

Answer 19: Non‐segregated phase bus should be in compliance with 26 25 00.00 26 Bus Structures.

20. 2.10 Please specify model number of the brush holders and brushes that are currently in use.

Answer 20: See the answer to Question 7 posted in Amendment 3.

21. 2.14 Should item (a)complete rectifier bridge assemblies be a “ready drop‐in replacement” including the same mechanical frame, 6 SCRs, 6 fuses, snubber circuits, all monitoring (temperature, flow, failed fuse etc.) and redundant cooling fans. If so, should item (p) four cooling fans still be furnished separately?

Answer 21: Such a design is acceptable, but not required. Spare part should be supplied to completely satisfy Section 48 19 00.00 26, paragraph 2.14, but may be supplied as individual components if that is how they should be installed.

22. 3.1 The contract drawings indicates that the DC bus duct shall enter the collector ring housing at about 2‐

3 feet height. Is this the government’s preferred routing? Another option would be to enter the collector ring housing closer to the generator floor plates, remove all exciter field poles and connect cables from the bus duct to the collector ring stubs. In either case, the bus duct needs to be removable in case of generator work. Please confirm if this routing is an option and if it would be more preferable by the government from a serviceability point of view. In particular for unit 1, being a “visitor unit with plexiglass around”, it may make sense to have a routing that provide as little obstruction as possible.

Answer 22: The Contractor shall bid the design as shown in the contract drawings. An alternative design may be entertained following award, but would be subject to Government approval.

23. 3.3.3.2.a Please confirm that the reference to PPTs here refers to the 25kVA 480/240V transformer used for the old exciter (page 7713952 in the reference drawings and page ED101 in the plan drawings).

Answer 23: The 480/240V transformer shown on reference drawing 771395‐2, sheet 12 of 31, shall be removed as part of the existing excitation cubicle. The PPTs identified on drawing ED101 are the Station Service Switchgear transformers and shall remain.

24. 3.3.3.2.a In order to provide a more accurate cost related to the removal of the existing excitation systems, we are asking for more information, as follows. As the existing excitation cabinets do not fit through the doors out to the turbine floor, they would need to be cut in smaller sections. Please confirm if there is any asbestos related material inside the excitation cabinets or if the asbestos only pertains to the external cables. If the existing cabinets have internal asbestos wiring or components contacting asbestos, such material would need to be abated, which would require a tent with negative air pressure etc. If so, should the entire cabinets be considered asbestos contaminated? Is the weight of the existing cabinets known, as asbestos disposal cost is directly related to the weight being disposed.

Answer 24: Testing was performed on insulation for wiring leaving the excitation cubicle (ED605). The insulation tested positive for asbestos, but it is in a non‐friable condition. A similar insulation material was found on wiring internal to the excitation cubicle, but was unable to be tested. It is assumed to also contain asbestos.

The weight of the existing cabinet is unknown.

25. 3.3.3.2.e The specification asks for exciter commutator brush rigging and supports to be removed. Would the exciter field poles also need to be removed (question related to 3.1)?

Answer 25: The exciter field poles may be removed if necessary for Contractor design, but removal is not required as a part of this contract.

26. 3.3.3.2.f We were not able to inspect the 13.8kV location for the existing CT that needs to be removed and 3 new CTs to be procured and installed by the contractor. Would it be possible to show a photo of the location to determine the space available for the new CTs?

Answer 26: See the answer to Question 6 posted in Amendment 3.

27. 3.3.3.3 Please provide estimated height of the cable tray serving the cables between the existing exciter and unit control board. Based on the site visit, we estimate the distance to be 20‐25 feet in which case scaffolding etc. needs to be built to allow for safe removal of asbestos cables as well as for installation of new conduit/tray from the new exciter location to the unit control board.

Answer 27: See drawing S‐CC 56/165 on page 18 of 64 in the Reference Drawings.

28. 3.3.7 Previous USACE excitation contracts have included collector ring inspection and replacement of brushes/holders in the base bid and collector ring refurbishment as an option, typically as separate costs for refurbishment in place and refurbishment off‐site. Once the collector ring inspection is performed, the subsequent report will provide information regarding the proposed refurbishment, depending on the severity of the grooving of the collector ring. In the event the grooving is severe, the collector rings would need to be removed and machined off‐site, which will require more demolition work, in particular for the Kaplan unit. Please clarify if we should provide a proposal for refurbishment in place or alternatively if we should factor in the worst case scenario, in case the inspection determines that the collector rings need to be removed.

Answer 28: The option to refurbish the collector rings in place or office is to allow for the standard practice of the Contractor and is not reflective of the severity of damage.

29. 3.3.7 Please clarify if the exciter field poles shall be removed to provide access for the DC cables to connect from below in addition to the removal of the commutator brush rigging and supports.

Answer 29: Some or all of the field poles may be removed if necessary for the Contractor’s design.

30. 3.3.8.3 and 3.3.8.4 In the event that there is not sufficient water or in the case of other external factors to the excitation system that limits the generator output at the time of commissioning, please clarify if it is the Contractor’s responsibility to cover the cost of additional trips or if such trips will be handled as change orders.

Answer 30: It is not anticipated that the Contractor would not begin commissioning if the generator output is limited by any factors. If additional trips are required due to factors not caused by the Contractor, they will be handled on a case by case basis.

SECTION 00 10 00 - SOLICITATION

BID SCHEDULE

BID SCHEDULE

CLARENCE CANNON POWERHOUSE EXCITATION SYSTEM REPLACEMENT

LINE

ITEM DESCRIPTION

ESTIMATED

QUANTITIES

UNIT UNIT PRICE AMOUNT

BASE LINE ITEMS

0001 Mobilization (SECTION 48 19 26.00 26) 1 JOB $__________ $__________

0002 Demobilization (SECTION 48 19 26.00 26)

1 JOB $__________ $__________

0003 Design, manufacture, and deliver Excitation Systems (Digital, Static) and appurtenances (SECTION 48 19 26.00 26)

2 EA $__________ $__________

0004 Disassemble and remove existing Excitation Systems (SECTION 48 19 26.00 26)

2 EA $__________ $__________

0005 Install Excitation System and appurtenances; modify existing powerhouse control panels; deliver and install external wiring, cabling, conduits, and bus (SECTION 48 19 26.00 26)

2 EA $__________ $__________

0006 Furnish and install new brush riggings, brushes, and brush holders (SECTION 48 19 26.00 26)

2 EA $__________ $__________

0007 Refurbish existing collector rings

(SECTION 48 19 26.00 26)

2 EA $__________ $__________

0008 Furnish and install shaft grounding systems (SECTION 48 19 26.00 26)

2 EA $__________ $__________

0009 Concrete removal and floor repair

(SECTION 03 60 00.01 26)

2 EA $__________ $__________

0010 Perform factory acceptance testing on Excitation Systems (SECTION 48 19

26.00 26)

1 JOB $__________ $__________

0011 Training (SECTION 48 19 26.00 26)

0011A Operator Training 2 EA $__________ $__________

0011B Technician Training 1 EA $__________ $__________

0011C 6-month Re-Training 1 EA $__________ $__________

0012 Prepare and deliver Operations and Maintenance Manual(s) (SECTION 48 19

26.00 26)

1 JOB $__________ $__________

0013 Furnish special tools and spare parts

(SECTION 48 19 26.00 26)

1 JOB $__________ $__________

0014 Perform field testing and commission Excitation Systems (SECTION 48 19

26.00 26)

2 EA $__________ $__________

0015 Perform model validation testing and furnish reports on Excitation Systems

(SECTION 48 70 01.00 26)

2 EA $__________ $__________

0016 Asbestos Abatement Work (SECTION 02 82 14)

0016A Asbestos Abatement – Unit 1 1 JOB $__________ $__________

0016B Asbestos Abatement – Unit 2 1 JOB $__________ $__________

SUBTOTAL FOR BASE LINE ITEMS $ _

OPTIONAL LINE ITEMS

0017 Skilled Craftsmen Hours

0017A Electrician Hire 100 EST MH $__________ $__________

0017B Machinist Hire 100 EST MH $__________ $__________

0017C Welder Hire 100 EST MH $__________ $__________

0017D Painter Hire 100 EST MH $__________ $__________

0018 Vectorizing Asbuilts 400 HR $__________ $__________

SUBTOTAL FOR OPTIONAL LINE ITEMS $ _

TOTAL FOR ALL LINE ITEMS $ _

SECTION 01 00 00 - GENERAL REQUIREMENTS

SCOPE OF WORK

Specification will be attached separately.

(End of Summary of Changes)