Q_&_A_,_Fort_Randall_480_Volt_Switchgear_Breakers_14SEP17.pdf

Fort Randall 480 Volt Station Service Breakers Additional Bidder Questions and Answers

14 September 2017

Q27: In Amendment 3 Bidder questions document, A14 states "Breakers are all rackable and do not require an outage for replacement". However, the specified scope of work for breaker retrofill requires an outage. Please clarify.

A27: It is concurred that the retrofill work will require an outage. Replace A14 with the following:

The Contractor will be required to submit a proposed work plan and outage schedule for approval by the Government. See spec SECTION 26 08 01.00 26 paragraph 1.5 General Requirements and spec SECTION 26 23 10.10 26 paragraph 3.1.b in amendment 4 for revised outage planning information.

Q28: Regarding primary disconnects 075 and 077, the drawings and photo of the existing switches indicate that the switches are to be duplex type. The specification leads us to believe the switches are stand-alone. Please advise if a duplex switch or stand-alone switches are required.

A28: 075 and 077 are “stand-alone” switches that operate independently of each other.

Q29: Reference spec section 2.2 15kV Air-Break Switches. The specification indicates that the equipment is to be rated for outdoor use and is to be weather proof. All indications are that the equipment is to be installed indoors. Our question is should the gear to be rated for indoor or outdoor use and do the bases, frames and channels of the enclosure need to be stainless steel as detailed is 2.2.1.1?

A29: Section 26 11 16, paragraphs 2.2 and 2.2.1.1 have been reedited to be indoor service, NEMA 1 with galvanized steel base.

Q30: Will the new 15kV switches be close-coupled to the transformer or is the transformer to be cable connected?

A30: Existing switches are bus connected on the bottom and cable connected on the top of the switch.

SWITCH 075

Q31: Given that breaker tripping times and trip elements will be changing as a result of the retrofill will USACE be requiring any updates to the electrical model, coordination, and arc flash labeling by the engineer?

A31: Not in this contract. This will be done by others.

Q32: Is all required wiring for low voltage signals to be integrated, currently residing in the required cubicles?

A32: Yes, all control wiring is existing. The controls schemes/interlocks are not changing.

Q33: The optional bid Item # 0011 related to the bracing activity is unbiddable until the bracing study has been completed? What assumptions should be made for bidding Item 11.

A33: Braces will be bid on a per unit price. A forthcoming amendment will address this issue.