B08 Questions and Answers for solicitation W9124A22R0007.pdf

Questions for solicitation W9124A22R0007- Replace Chillers Building 81504 8 July 2022

1. Apparently, there were new drawings issued or engineering done. Is the engineering team going to engineer the job to ensure that the plant will be set up for centrifugal’s vs.

screws?

Answer: The contractor, and their design engineer, shall determine whether a screw or centrifugal chiller installation is to be performed.

2. Does Government want the technician in charge of installation of the chillers to have factory certification for the chiller being installed?

Answer: Yes, the contractor’s technician shall be factory certified.

3. The government states this is a design build. Does the government require stamp mechanical and electrical drawings?

Answer: Yes, the contractor shall submit stamped mechanical and electrical drawings.

4. New VFDs CHW there are no control points for speed control how is it being controlled?

Answer: The contractor shall provide a control point for VFD speed/frequency control for each new VFD. Presently, the system is operated at full speed (manual). The contractor shall determine the full range of VFD control setpoints. The contractor shall review plant operations and existing control system for a full week during both the heating season (late October to late March) & cooling season (late March to late October).

Before starting the design, the contractor shall attend a meeting with Schneider Electric, DPW, and plant operators to discuss the controls and current plant operating procedures.

This meeting will be arranged by DPW. (See question #16)

5. We are installing all local Chiller control, Chiller specs are calling for a lot of local program points, sensor and display programming is there going to be factory start up for verification or is contractor doing start up?

Answer: The contractor shall perform the start up. (See the answer to question #2)

6. Provide nameplate to existing VFD and Transformer. Amperage, voltage, phase and

KVA.

Answer: Photos with this information are provided in the attached document titled “North Plant Chiller Photos”.

7. Currently there is not a disconnect for transformer or VFD to re-use as per SOW. Is Contractor to provide and install a disconnect to protect transformer and/or VFD?

Answer: Yes, the contractor shall provide and install a disconnect switch for each transformer and VFD.

8. Currently there is not a disconnect to re-use for the chiller as per SOW. Is Contractor to provide and install a disconnect to protect chiller?

Answer: Yes, the contractor shall provide and install a disconnect switch for each chiller.

9. Are the existing electrical components to the new equipment to be changed to raintight fittings? NEMA rating?

Answer: No, the existing electrical components do not need to be changed/upgraded to rain tight fittings. NEMA 1 is acceptable.

10. Requesting photos to the following:

a. Existing Chillers

b. Existing transformer and VFD

c. Entire chiller room

d. Entire electrical room

e. Main Distribution Panel and breakers

f. Sub panel inside electrical room and breakers

g. Nameplates to all electrical components (chillers, chilled water pumps, motors, and panels)

h. Sub floor (basement) where the pumps are located.

i. Exterior area to review laydown area.

Answer: Photos are provided in the attached document titled “North Plant Chiller Photos”.

11. What company maintains the EMS controls on Ft Huachuca?

Answer: Schneider Electric maintains the controls for the North Plant specifically.

Currently, no base-wide Energy Management & Control System (EMCS) exists.

12. Will the government provide storage space for chiller if necessary?

Answer: No, the Government will not provide a secure location for the chillers to be stored before they are ready to be installed. If the 3 chillers are to be delivered at the same time, they shall be stored off-post, at a contractor’s location, until each unit is ready to be installed. (See question #24)

13. Please provide pictures of existing pumps & piping

14. Please provide pictures of existing chillers & piping

15. Please provide pictures of existing chiller control valves

16. Is the existing control system a fully functional system, if not what is not working?

Answer: The existing Schneider Electric control system is minimal, and not fully functional. The existing chillers provide a few control points, but the systems are still operated in hand. Flow switches don’t appear to be functional.

The contractor shall review plant operations and existing control system for a full week during both the heating season (late October to late March) & cooling season (late March to late October).

Before starting the design, the contractor shall attend a meeting with Schneider Electric, DPW, and plant operators to discuss the controls and current plant operating procedures.

This meeting will be arranged by DPW. (See question #4)

17. Can the government provide the system exiting point list for DDC control input/output summary?

Answer: No. The control points for the existing chillers are minimal.

18. Can the government provide the mechanical control diagrams for the existing DDC control systems?

Answer: No.

19. Is there an existing hoist system for lowering pump into basement and the removal of existing?

Answer: No, there is no existing hoist system for lowering or raising pumps.

20. The existing As-builts for central plant piping schematic show only control valve V-16, V-17, and V-18, (one per chiller). Is there a new drawing that shows the 3 per chiller?

Answer: The as-builts only show the existing pneumatic control valves on the condenser water supply for each of the three chillers. There are also pneumatic control valves on the condenser water return and condenser water bypass for each chiller.

21. Does the Government have a list of Control Valve for the Central Plant? If so, can you show the valve you would like us to replace and their location.

Answer: The list of control valves to be replaced include the valves listed: The pneumatic control valves stated in section 4.10.01 are located on the condenser water supply, return, and bypass, next to each chiller. The chilled water isolation valves stated in 4.10.02 are the isolation valves for each chiller on the chilled water supply side. The contractor shall determine the full list of control valves to stay or be replaced.

22. What will be the acceptable time frame for the removal and replacement of the existing chiller supply isolation valve? Will the government support the removal by isolating the system for removal?

Answer: These are the isolation valves for each chiller on the chilled water supply side.

Since the chillers are in series with the CHW pumps, and their isolation valves, each of the CHWS isolation valves can be replaced at the same time as its chiller. The Government will support the removal by isolating the individual chiller and its associated pump and piping.

23. PPQ: Can a subcontractor’s PPQs be used for this factor?

Answer: PPQ’s should be submitted by the prime contractor, and reflect their ability to complete the requirement listed in the solicitation.

24. SOO 4.08: Would the Government have a secure location for the Contractor to store the chillers until they are installed?

Answer: No, the Government will not provide a secure location for the chillers to be stored before they are ready to be installed. If the 3 chillers are to be delivered at the same time, they shall be stored off-post, at a contractor’s location, until each unit is ready to be installed. (See question #12)