Z1DA--528A7-23-102 add chiller rome VA cboc

Updated on October 11th, 2022

Addendum to solicitation 36C24222B0076, Add Chiller Rome VA CBOC, 528A7-23-102

Question: Please provide dimensions for new chiller, WC-1. Will the new chiller fit through the double doors to the mechanical room, or will it need to be disassembled?

Answer: The Government Furnished/Contractor Installed chiller will be shipped from the vendor in three major assemblies, on or about March 1st, 2023. The unit (chiller) is factory assembled, refrigerant piped, wired and leak tested, then dismantled for shipment. The compressor/motor assembly is removed from the shells and skidded. The evaporator and condenser shells are separated at the tub sheets and are not skidded. Refrigerant lines between the cells are closed and charged with dry nitrogen between 2 and 3 psig. The chiller s Variable Speed Drive will be packaged and shipped on a separate skid. Refrigerant, isolators, temperature controls, and wiring are shipped separately. The control center ships on the evaporator in the folded down position. The construction contractor will be responsible for rigging the three major chiller assemblies (evaporator, condenser, and variable speed drive, as described above), wiring, isolators, miscellaneous parts, and refrigerant bottles into the mechanical room door opening which is approximately 83 high and 70-1/2 wide. Refer to attached drawings Assembled Chiller Dimensions and Split Shipped Chiller Dimensions as well as the attached York 265 Ton YZ Chiller Selection information. The contractor shall then assemble the chiller assemblies, refrigerant lines, controls, and electrical wiring harnesses to factory specifications and charge the chiller with the R-1233zd(E) refrigerant.

Question: Is the new conduit to be EMT or GRS (galvanized rigid steel)?

Answer: The space in the mechanical room does not meet the definition of Hazardous (paragraph 3.6 of specification 260533) or Wet/Damp Locations (paragraph 3.7 of specification 260533), thus EMT is acceptable in the mechanical room, per paragraph 3.4 of specification 260533. Metallic electrical and control conduit sections penetrating the masonry wall to the exterior should be GRS and comply with paragraph 3.1 of specification 260533.

Question: Are we to use set screw or compression fittings for electrical conduit?

Answer: Refer to paragraph 2.1 of specification 260533.

Question: Do we re-use / modify the existing feeders (conduit & wire) for the relocated existing chiller WC-2 and re-use the existing circuit breaker?

Answer: To clarify Power Plan Keyed Notes 2 and 3 on EP-101, contractor may utilize existing conduit and electrical conductors to the extend desired. The conductors shall be tested per paragraph 3.9, Acceptance Checks and Tests, of specification 26 05 19 prior to reworking the conduit and conductors, and again after the rework. Re-use the existing circuit breaker for existing WC-2 per keyed note 2 on drawing EP-101.

Question: Who supplies any new Variable Frequency Drives (VFDs)?

Answer: The contractor supplies all materials except that shown on the drawings as Government Furnished or materials to be re-worked.

Question: What is the percentage of work that needs to be done by the Prime (SDVOSB)?

Answer: 25%

Question: Will the contract end date be extended to account for long lead times for some materials?

Answer: The contract end date shall be extended to April 30th, 2023 to accommodate the installation of the new chiller that is expected to arrive on site around March 1st, 2023 and for the long lead time of the contractor supplied Variable Frequency Drives. Existing chiller, WC-2, is still required to be operational as no later than March 31, 2023, or 90 days from contract award, whichever is later. The existing chiller will operate without the new Variable Frequency Drives (see note 4 on EP-101) on the condenser water pumps, thus the receipt of the Variable Frequency Drives should not delay the requirement for WC-2 s operation.

Question: Will the on-site assembly of the chiller require third party oversight, and if so, who will contract for this service?

Answer: The chiller s major components (evaporator barrel, condenser barrel, motor, VFD, refrigerant, and wiring harnesses) will require assembling by the contractor with oversight from York/Johnson Controls. The contractor shall procure the services of a factory trained and authorized representative of York/Johnson Controls who has the experience necessary to provide oversight and assistance with the assembling of the Government Furnished/Contractor Installed York YZ chiller to maintain the factory warranties.

Question: Marine Water Boxes typically require insulation to be applied in the field. Do these Marine Water Boxes require the insulation to be field installed and who is to provide the insulation?

Answer: The Marine Water Boxes on the ends of the evaporator barrel require field applied 40 mm (1.5 inch) minimum thickness of flexible-elastomeric thermal insulation, complying with ASTM C534. The contractor shall provide and install the insulation. The insulation shall be installed so that it is partially removable and allow access and opening of the water boxes without damage to the insulation.

Question: Specification section 26 05 19, page 6, Existing Conductors states not to reuse existing conductors. However, Note 2 on drawing EP-101 indicates to rework existing circuit referencing the relocated Chiller WC-2. The same would be for Note 3 and Note 5 on the same drawing EP-101 as it relates to the CHW Pumps 1 and 2 as well as the New Refrigerant Monitor.

Answer: Specifically for the power to WC-2, CHW Pumps 1 & 2, and the Refrigerant Monitor, only, the contractor may reuse and rework the existing conductors. The conductors for chiller WC-2 and CHW Pumps 1 and 2 shall be tested per paragraph 3.9, Acceptance Checks and Tests, of specification 26 05 19 prior to reworking the conduit and conductors, and again after the rework.

See attached document: york chilller selection.

See attached document: split shipped chiller dimensions.