140020_Pre Bid RFI Responses.pdf

DEPARTMENT OF THE AIR FORCE

HEADQUARTERS 72 AIR BASE WING (AFMC)

TINKER AIR FORCE BASE OKLAHOMA

08 May 25

MEMORANDUM FOR AFSC/PZIOC (ATTN: Sara Hinds)

THROUGH: 72 ABW/CENM

FROM: 72 ABW/CEED

Tepa Companies

SUBJECT: Pre-Bid RFI Responses Project: WWYK140020 Replace Unit Substation & Switchgear, Col V51, B3001

Reference: Memo, 18 Apr 2025, Pre-Bid RFIs, WWYK140020 Replace Unit Substation &

Switchgear, Col V51, B3001

1. This office reviewed the referenced RFIs for the subject project and provided answers below. Please forward to the contractor(s) for their use in preparing proposals.

(1) SOW 4.4.3.2 states to provide new 12.47kv cable shall be supplied from the secondary side of V67 spare switch to new V67 Unitized substation tie switch. The existing 12.47kv feed appears to be fed from a Mezzanine at column line P53 not vault 12. Can we re-feed the new equipment from the existing switch at Column P53?

Government Response: It is acceptable to re-feed from Column P53. Need to verify electrical loads since this information is not available. Amended SOW, Design Analysis and Drawings (Rev 01) are forthcoming.

(2) If we are reusing the existing breaker at P53 for the new substation feed, can we reuse the existing 12.47kv wire if we have it tested?

Government Response: Existing 12.47 kV cables cannot be reused. Amended SOW, Design Analysis and Drawings (Rev 01) are forthcoming.

(3) Can we reuse the existing North/South bus feed wiring and just reconnect it to the new switchgear?

Government Response: Existing cables cannot be reused. Amended SOW, Design

(4) SOW mentions a West bus but during the site visit we did not see it. Can you confirm if there is a West bus tied to the existing substation?

Government Response: West bus duct is not tied to the existing substation. Amended SOW, Design Analysis and Drawings (Rev 01) are forthcoming.

(5) SOW paragraph 4.3.1 (3)(a) states that Sub V51 is fed from Vault 12; this does not appear to be correct. The existing 15kv cable traces back to a 15kv fusible switch at switching station P52 (sometimes called R53). The existing 15kv cable was installed in 2008 and is in excellent condition. Will it be acceptable to retain and reuse the existing 15kv cable?

Government Response: Existing 15kV cables shall be replaced. Amended SOW, Design Analysis and Drawings (Rev 01) are forthcoming.

(6) The last sentence of narrative paragraph 7.2 says “all 600V cable feeding from secondary side switchgear to the west 480V bus shall remain.” There is no west bus feed from Sub V51. SOW paragraph 4.3.1 (3)(b) says in the first sentence that the secondary conductors feeding the north and south bus are to be removed. The next sentence seems to say that all 600V secondary conductors are to be disconnected but not demolished and retained for reuse. Will it be acceptable to retain and reuse the existing secondary conductors from the secondary switchgear at Sub V51 to the existing north and south busways?

Government Response: Existing secondary conductors from the secondary switchgear at Sub V51 to the existing North and South busways shall be replaced.

Amended SOW, Design Analysis and Drawings (Rev 01) are forthcoming.

(7) Sub V51 is fed from a fusible switch at platform P53 (R53). This fusible switch can serve as both the disconnecting means and overcurrent protection for Sub V51 and also includes provisions for lockout/tagout. Consequently, will it be acceptable to eliminate the 15kv fusible switch at the new Sub V51 and provide only a 15kv termination cabinet?

Government Response: The 15kV fusible switch at the new Sub V51 can be eliminated.

(8) RFP drawing E-101 keynote 5 appears to call for a remote-control cabinet. What are the required functions of this cabinet? Is the remote-control cabinet intended to be readily accessible from the plant floor?

Government Response: Remote control cabinet is to be located on the Plant floor.

The function is identical to the one installed at Column V67. Amended SOW, Design

(9) The single-line diagram on RFP drawing E-101 shows three secondary branch breakers feeding three busways; the existing Sub V51 has only two existing branch breakers feeding two busways (north bus and south bus). There is no west bus fed from the existing Sub V51. The diagram also indicates one prepared space, presumably intended to be suitable for a 1600AF drawout breaker. SOW paragraph

4.4.1.5 requires one spare 1600AF adjustable breaker. Is it the RFP/SOW intent to require a total of three (3) 1600AF/1200AT secondary branch breakers (one spare) and provisions to add one future 1600AF adjustable branch breaker?

Government Response: The RFP/SOW is to provide two (2) secondary branch breakers and a spare for future use. Amended SOW, Design Analysis and Drawings (Rev 01) are forthcoming.

(10) Existing Sub V51 has two existing grounding leads that appear to be #4/0 copper, tied to building steel. Will it be acceptable to retain these existing leads and connect them to the grounding lugs within new Sub V51?

Government Response: If the existing ground leads are in compliance with code, it can be used.

(11) Is a circuit breaker lifting device required under this contract?

Government Response: A circuit breaker lifting hoist is required under this contract.

Amended SOW, Design Analysis and Drawings (Rev 01) are forthcoming.

(12) Is a portable and corded remote racking and/or remote switching station required under this contract?

Government Response: Remote racking/switching station is required under this contract. Amended SOW, Design Analysis and Drawings (Rev 01) are forthcoming.

2. The points of contact for this project are:

a. Shane Vines, Project Manager. PH: 582-4802

b. Adam Gibson, Construction Inspector. PH: 736-5028

c. Joshua Wheeler, CSAG Program Manager. PH: 582-4826

d. Matt Morris, Contracting Officer Representative (COR). PH: 736-7081

Shane Vines Matt Morris Project Manager Electrical Engineer/COR 72d Civil Engineering Directorate (Tepa) 72d Civil Engineering Directorate

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