Additional Questions and Answers - Bldg 70.pdf

1. Will contractor/manufacturer be responsible for programming exercise timers or will owner handle after installation? Yes

2. A building shutdown will be required to install new automatic transfer gear. Will there be any special requirements for this shutdown (i.e. weekend/after-hours work or temporary power)? We do anticipate a building shutdown for the install, no requirement to provide temporary power or do weekend/after-hours.

3. Service and Transformer are Mississippi Power. Is contractor to coordinate with MS Power or will owner coordinate with electrical service provider? Contractor will coordinate through government rep who will coordinate with MS Power

4. At site visit it was mentioned only minimum diesel will need to be placed in tank by contractor to accomplish startup and commissioning. Owner will fill tank. Please confirm. Confirmed

5. Per discussion at site visit, new foundation for generator will have a shallow placement to avoid any underground interferences. Please confirm. Confirmed

6. Can site drawings showing existing underground mechanical, plumbing, electrical, and communication installations in the area of work be provided prior to bidding?

No

7. Conduit and conductors from new transfer switch to new generator will be routed above ground at grade similar to existing installation. Please confirm. above ground is preferred and more cost effective.

8. Will new generator require a 400-amp main breaker to match cabling requirements?

9. Will spare conduits be required from new ATS to new Generator for future increase to 1200-amp capacity? No

10. Is there any requirement for a remote annunciator for monitoring the generator/ATS/fuel tank? No

11. Does the owner need an adder to install conduit runs underground between transfer switch and generator?

12. Outdoor electrical conduits are to be PVC-Coated Rigid Galvanized Steel. Please confirm. Outdoor rated

13. What material is required for indoor electrical conduit? None anticipated

14. Generator is to be sized per manufacturer standby rating. Prime rating is not required. Please confirm. Standby rating

15. The existing conductors from the existing transfer switch to the existing MDP are sized and rated properly, in good working order, and are to be reused. Please confirm. Reuse.

16. Period of Performance The combined solicitation requires completion within 90 consecutive calendar days, while Section 6.0 of the Statement of Work establishes a 180-calendar-day period of performance, including 15 days for submittals, 135 days for procurement, and 30 days for installation and testing. Please confirm which period of performance governs. 180 days

17. Generator Rating – 125 kW vs. 125 kVA The Statement of Work specifies a 125 kW generator. However, Attachment 2 identifies the proposed generator as a 125 kVA generator on one of the site drawings. Please confirm whether the required generator rating is 125 kW or 125 kVA. 125kW/156kVA

18. Generator Electrical Rating If 125 kW is the correct rating, please confirm the required generator kVA rating, full-load amperage, and generator output circuit breaker rating at 208/120 V, three-phase, four-wire.

1. Building Voltage: 208Y/120V, 3-Phase, 4-Wire

2. MDP: 1200A, 10kAIC Rated GE Panelboard fed with (3) Runs of: 4#500kCM CU Conductors

3. Measured Maximum Current:

a. A Phase: 232A – 7/15/26 @ 2:53pm

b. B Phase: 214A – 7/7/26 @ 3:02pm

c. C Phase: 219A – 7/17/26 @ 2:49pm

4. Measured Maximum Power: 73.2kW/79.8kVA

5. Measured Average Power: 26.1kW/26.8kVA

6. Measured Average Power Factor: 0.98 Lagging

7. Measured Average THD Volts: 1.96%

8. Measured Average THD Amps: 11.4%

a. Average 3rd Harmonic Current: 5.1%

b. Average 5th Harmonic Current: 2.1%

c. Average 7th Harmonic Current: 3.5%

19. Generator Feeder Conductors

The Statement of Work specifies four 500 kcmil copper conductors between the generator and ATS. Please confirm whether the Government requires exactly one 500 kcmil conductor per phase and neutral regardless of the selected generator's nameplate current and output breaker rating. See above

20. Existing Electrical System Information Please provide, if available, the following information for the existing 225 kVA transformer and associated distribution system: Unavailable at this time

a. Transformer secondary voltage

b. Transformer impedance

c. Transformer secondary overcurrent protection

d. Existing MDP bus and main rating

e. Available fault current

f. Existing feeder conductor sizes

21. 1200 Amp ATS Main Breaker Rating The SOW requires a 1200 A service-entrance-rated ATS with an integral service disconnect breaker. Please confirm the required trip rating of the normal-source breaker. Is a 1200 A frame with an adjustable or reduced trip setting acceptable?

YES that is acceptable

22. ATS Neutral Configuration Please confirm whether the ATS is required to be:

a. 3-pole with solid neutral

b. 4-pole with switched neutral.

23. Please also confirm whether the generator is intended to be configured as a separately derived system. See above

24. Manual Bypass/Override Requirement The SOW requires the ATS to include "manual bypass/override capability." Please clarify whether the Government requires a true bypass-isolation automatic transfer switch or whether manual transfer capability on a standard automatic transfer switch satisfies this requirement- Yes

25. ATS Fault Current Rating Please provide the required ATS withstand and closing rating/SCCR and the available fault current at the proposed ATS location. unknown

26. Existing Normal and Load Conductors Please confirm whether the existing conductors associated with the existing 1200 A manual transfer switch are to be reused, extended, or replaced. Specifically, please clarify whether new conductors are required from: Replace MST with ATS and utilize existing conductors from MTS to BLDG 70 MDP. New Insulated AG conductors from ATS to Generator.

a. Existing MDP to the new ATS

b. New ATS to the Bldg 70 distribution panel.

27. Existing 100 kW Generator The site drawing identifies an existing 100 kW MEP generator connected to the existing manual transfer switch. Please clarify the disposition of the existing generator and associated power/control wiring after installation of the new generator and ATS. Should the existing generator be removed, abandoned in place, returned to the Government, or remain operational? MEP Generator will be removed by military.

28. Building 70 Power Outage Please identify:

a. Maximum allowable outage duration (72 hours/3 working days)

b. Permitted outage/work hours 0800 – 1630 daily (will schedule with building operators)

c. Required advance notification YES, always

d. Government switching requirements, if applicable Negative

e. Whether temporary power is required during replacement of the existing transfer switch Negative

29. Generator and ATS Concrete Pads Please provide the required structural and environmental design criteria for the generator and ATS pads, including, if applicable: Maintain additional 8” perimeter to specified sub-base tank size

a. Minimum concrete strength 4000PSI @28 days

b. Pad thickness 6” minimum

c. Reinforcement requirements #5, grid spaced @ 12 inch on center each way

d. Equipment anchorage requirements doweling required

e. Wind-loading criteria No

f. Seismic criteria No

g. Flood-elevation requirements No

30. ATS Mounting Arrangement The SOW appears to reference both installation of the ATS on the exterior of the equipment enclosure and anchoring the ATS to its own concrete pad. Please clarify the required ATS mounting arrangement and exact intended location. Replace MTS with ATS in same location

31. Generator Sound Attenuation The SOW specifies a "Level 1 Sound and Weather Attenuation Enclosure." Because acoustic classifications vary among generator manufacturers, please provide any required maximum sound-pressure level in dBA and the required measurement distance. 70-89 @ 23 feet

32. Fuel Tank Requirements Please confirm any specific requirements for the minimum 250-gallon double-wall sub-base fuel tank, including:

a. UL listing/certification UL142

b. Tank venting Yes

c. Remote or direct fill arrangement

d. Leak detection Not required

e. Overfill prevention Standard UL subbase fuel tank

f. Required environmental or Base-specific fuel-storage requirements Negative

33. Load Bank Testing The SOW requires a two-hour load-bank test. Please confirm the required testing duration at each load step, including 25%, 50%, 75%, and 100% load. Please also confirm that the contractor is responsible for furnishing the load bank, temporary cabling, and all test connections. 25% 15 mins, 50% 15 mins, 75% 30mins, 100% 30 mins. Contractor responsible for load bank testing and report.

34. Generator Feeder Sizing & Breaker Compatibility

a. Issue: The SOW currently calls for a 125kW, 208/120V, 3-phase, 4-wire generator to be paired with (4) sets of 4-500kcmil Copper (CU) feeders. This configuration yields a 1,520A capacity. However, a 125kW generator at this voltage outputs roughly 434A, and standard manufacturer units are equipped with a 600A breaker. A 600A breaker mechanical lug typically only accepts up to (2) parallel conductors.

b. Question: Are the 4 sets of 500kcmil CU feeders an oversight in the SOW? We recommend modifying the feeder schedule to (2) sets of 4-350kcmil CU, which safely supports the 600A breaker capacity and physically fits the generator’s termination lugs. Please confirm if this alternative is acceptable.

The recommendation of 2 sets of 4-350kcmil is acceptable