W50S8524B0003 RFIs as of 20 June 24.pdf

Requests for Information (RFIs) and Answers

W50S8524B0003 – VGLZ 242006, Replace Section of Medium Voltage (MV)

Feeder 1 from SW1‐6 to SW1‐12

Q1. Feeder from SW1‐6 to SW1‐12 goes through SW1‐9, SW1‐10, SW1‐11, before ge ng to SW1‐12.

Will we be termina ng each of these or is there a straight shot between the 2?

A.1 Please see page 2 of the drawing for the subject project. Each sec on is from switch to switch;

Conductor is to be replaced in each sec on with new termina ons. 3rd party tes ng is required before energizing.

Q2. Are there scalable drawings available for this project?

A2. Scalable drawings are not available for this project.

Q3: Per SOW paragraph 1b. Please confirm the two breakers in Building 854 have been tested and are ready for use.

Q3. Unknown status of service contract to repair main switch house breakers, it is known the field MV switches can safely isolate and lock out voltage for downstream work. It is thus known the work is not dependent on breaker repair.

Q4: Please confirm existing cables are free of lead.

A.4 There is no known lead in the existing feeder conductors.

Q5. Shut down and re‐energize the switches. Will it be done by 127?

A5. Two‐week notification is required to schedule and approve overtime work and power outage as per SOW, the base electrical maintenance workers will (operate MV switches), isolate the feeder at the upstream MV switch, the contractor is responsible for lock out tag out, and verification of power isolation.

Q6. MV SW1‐6: Does this designation refer to a single switch or a range of switches?

A.6 This is a given address of one switch location pertaining to a 2018 power study.

Q7. When you mention excavation, are you referring to the installation of additional conduits and wires? If so, are the conduits rigid or PVC?

A7. Boiler plate environmental topic, intent is to remove conductor from existing duct bank and pull new conductor is same duct bank.

Q8. Are the transformers being de‐energized designed in such a way that they must be de‐energized before you can open the doors? In other words, do they need to be de‐energized before opening the doors, or can the doors be opened first to then de‐energize them? We were informed during the site visit that the transformers could not be opened without shutting them down.

A8. MV switches need power to be isolated before opening the door, not transformers.

Q9Are the connections to the transformer pressed on lugs that are then bolted to the transformer, or are they high voltage boot connections?

A9. This scope covers MV switch to switch conductors and terminations. Awarded contractor will need extensive experience with termination of MV conductors. Transformer terminations are not in contract.

Q10. Additionally, during the site visit, it was decided that we are locking and tagging the downstream transformer, not the upstream one. We just want to clarify that the upstream transformer will be the one that will be locked out.

A10. Upstream power shall be isolated by base electrician, lock out tag out is responsibility of contractor as well as testing to ensure power is isolated.

Q11. It was mentioned yesterday that back feeding and isolation of the segment of the downstream transformer feeds that are being removed and replaced might be done to reduce the magnitude of each outage. Our question is: is this part of the plan for this project?

A11. This was never part of the objective. Hearsay based on capability of existing service function.

Q12. Secondly, if that is the plan, are you planning to have a lockout on the downstream end to prevent back feed re‐energizing of the segment to be removed and replaced? We feel these are very important questions and procedures that need to be clarified to prevent accidents or injuries. Also, we need to know what equipment will be required to reconnect the new conductors.

A12. If such a plan was entertained to limit power outage, further protections of LOTO and field switches isolation would be required.

Q13: Will the language pertaining to the testing of the MV Breaker be removed from the solicitation in an addendum?

A.13: This deletion is not necessary.

Q14: Is the 4800‐volt line three phase or single phase?

A14: 3 Phase