Attachment 5.pdf

JFTB HANGAR 1 REPAIRS PHASE 2

ADDENDUM 2 – 11 MARCH 2010

CLARIFICATIONS

Addendum 1 Demolition Clarification

Demo and remove all items circled in red or marked with red paint in Addendum 1 Photos per specification Sect. 01732 – Selective Demolition.

Items identified as “Blackout Lights” in Addendum 1 Demolition Photos are Heat Activated Devices (HAD’s). See DRAWINGS below.

Items shown in Addendum 1 Demolition Photos are meant to provide for demolition of systems not being replaced, and or, to augment systems that are being replaced.

Existing Mechanical, Electrical, Plumbing and Fire Systems that are being replaced should be demolished in their entirety.

DRAWINGS

F-1 General Note 1.a.: Demolition of the existing hangar bay deluge systems shall include all Heat Actuated Devices (HAD's) and all associated copper air tubing and conduit."

RFI’s

1.01 Q: Drawing E-2 note 1. States to install new light fixtures, connect it to the specified circuit in panel. Where is the point of connection for these new fixtures? Do we use the existing conduit and wiring from existing lights to each panel? Do we remove the existing type A fixtures?

A: The 64 new lighting fixtures are grounded in 16 rows. Route the circuits for each row in a common conduit over to the column line in the center of the hangar. Extend the circuits from the new fixtures to the new control contactor panel located above the lighting panel without intermediate splices. Provide junction boxes and conduits as needed. The detailed design of the new conduit, boxes, and wiring shall be in accordance with NEC. Provide terminal blocks in the new control contactor panel for all external connections. The circuits to the new emergency lights shall also be routed through terminal blocks in the new control contactor panels to minimize the number of conduits. A new 1-1/4" conduit shall be installed from each of the 3 existing lighting panels to its new control contactor panel, for all of the new circuits connected to that lighting panel. note that all circuits will have no more than 10 amperes load.

1.02 Q: Drawing P-1 Pipe Schedule - compressed air piping is required to be "black steel with scrd MI fittings." Drawing P-5 Center Bay pipe run - compressed air piping is "copper type L." Which material is correct? If material is partial copper and partial black steel, please detail what areas are what material.

A: This question was answered in Addendum 1 Phase 2 for Drawing P-5.

JFTB H1 PH2 ADDENDUM 2 P-2

1.03 Q: Is the existing 2400 V electrical system, which is to be removed, still energized?

A: The 2400 V electrical system is no longer energized.

1.04 Q: Drawing E-6 Note 1 states to route parallel set of 1" conduit with 3#1 and 1#6 from panel to receptacle. 3#1 and 1#6 will not fit in a 1" conduit. Do these receptacles require a neutral conductor? What is the purpose of a parallel run?

A: Conduit size should be 1 ¼”. The receptacles do require a neutral conductor. The purpose of a parallel run is to reduce voltage drop for the 400Hz system.

1.05 Q: Drawing E-8 RENOVATION NOTE 2 states to furnish and install 1000A 120/208v 3 phase 4 wire panel. Route 1 1/2" conduit with 3#1 conductors and 1#1 ground.

Please verify that the conduit and conductors are sized correctly for 1000 amps. Also is a neutral conductor required? Are the 400hz convertors meant to be ran parallel or is this a redundant system?

A: Based on the estimated load the panel size can be 600A 120/208V 3PH 4W (sheets E-8 and E-9 shall read 600A panel instead of 1000A). The conduit and conductors should be 2 ½” conduits with single-insulated (3)-500 kcmil conductors and (1)-#3 ground. The 400Hz converters are meant to run parallel.

1.06 Q: Drawing E-8 Renovation Note 1 states to install 3/4" conduit with 3#8 and 1 #10 ground connected to a 150 amp breaker. By code you cannot install #8 wire on a 150 amp breaker. Please advise.

A: The corrected note should be 1½” conduit with 3#1/0 and 1#6 ground to new 150 amp breaker.

1.07 Q: Section 00100 Bidding Schedule/Instructions to Bidders Item 1 – Removal of Obsolete Equipment. Since Amendment 2 included photographs of equipment to be removed, is it necessary for the bidder to include a breakdown with a list of all items in bid? If so, is the list to include only removal items?

A: It is not necessary for the bidders to provide a breakdown. Bids should include all items circled in red or marked with red paint in the photos in addition to all items required for demolition in the contract documents per specification 01732 Selective Demolition.

1.08 Q: Drawing E-6 bottom right corner of sheet has a note "or connections to 100psi air, 110v A/C 400HZ power on pedestals or pilasters". Please clarify the meaning of this note.

A: Please disregard the Note.

1.09 Q: Due to the extended run length for the 400Hz positions, Voltage drop will be so great that the aircraft will not accept power. The requirement for aircraft external power is MIL-STD-

704. It is also attached.

A: According to UFC 3-555-01N standard/criteria and indicated conductor characteristics, the specified 3#1 and 1#6 ground conductors in aluminum conduit with a parallel run should have a voltage drop to meet the 113V-118V operating voltage of the H-60.

JFTB H1 PH2 ADDENDUM 2 P-3

1.10 Q. The leg breakers in panel MSB are undersized to support the Army H-60 Blackhawk.

A: Breaker size at panel MSB shall be rated for 80A.

1.11 Q: The system is unsafe as it allows a power cable to be energized when it is not plugged into the helicopter.

A: The current design shows each 400Hz receptacle controlled by an individual breaker at panel MSB. Each receptacle can be de-energized by the control of the breaker or by controls on the frequency converter.

1.12 Q: The conductors specified for the 400Hz runs will not fit into the specified conduit.

A: Conduit size shall be 1 ½” rigid aluminum conduit.

1.13 Q: The converters are individual 60kVA units and there is no criteria to parallel them or tie them to a common bus in panel MSB.

A: Parallel connection criteria is provided by the frequency converter manufacturer.

1.14 Q: With two 60kVA 173amp 400Hz 115/200VAC inputs, The bus bar is rated for 1000amps.

A: The two 60kVA frequency converters provide a connected load of about 350 amps. The 100 amp panel is designed to take on full load of the 12 stations plus possible future load.

1.15 Q: MSB shows a connected load of 108kVA. With two 60kVA inputs this load is 120kVA 346amps.

A: The provided load of by the frequency converters is designed to carry the full load of the 12 stations with a 50% demand factor as stated in UFC 3-555-01N Table 12.

1.16 Q: Are you going to be required to provide performance testing of the system, not just the converter?

A: No

1.17 Q: If so, do you have the load demands for the helicopter it is intended to support?

A: See 1.16 above.

2.01 Q: Section 02090 Item 1.01.1 States "Where rust exists the contractor will be required to sandblast those areas to a metal finish." Will the paint manufacturer accept an SP6 or "Commercial Blast" as the required "Metal Finish".

A: All rust shall be removed to an SSPC Commercial Blast Cleaned Surface Finish

(SP-6).

2.02 Q: Section 02090 Item 1.01.1 States "Where rust exists the contractor will be required to sandblast those areas to a metal finish." Item 3.02.1 states "Where sandblasting has disturbed paint on a smooth continuous surface, the paint will be removed completely in that area."

Where would "that area" end in the case of a joist or truss where spots of rust occur here and there? Where would that area end in the case of the doors in phase 3?

JFTB H1 PH2 ADDENDUM 2 P-3

A: Remove all rust areas to an SSPC Commercial Blast Cleaned Surface Finish (SP-6).

Paint may be feather sanded instead of completely removed from entire continuous adjacent surfaces at rust areas.

2.03 Q: Section 02090 Item 1.01.1 States "The underside of the wood decking will be scraped and sanded to receive new paint." Will sandblasting to an SP6 (Commercial Blast) be accepted in lieu of scraping and sanding of the wood deck?

A: Yes, if the wood surface area is not affected.

2.04 Q: Section 02090 Item 3.02.1 States "When surface preparation is complete an appropriate primer (wood, metal, etc.) will be applied to the prepared areas." Shouldn't this task be included under 09910 Painting?

A: Priming has been specified in Sect. 09910. Surface preparation for priming at lead containing paint is specified in Sect. 02090 including special provisions required when lead containing paint is made friable by sanding, sandblasting or other means. This can be accomplished by painters qualified in lead paint abatement or appropriate oversight by the painting subcontractor so that painting can be performed per Sect. 02090.

Work should be coordinated by the general contractor so that painting can be performed per Sect. 02090.

2.05a Q: Refer to sheet E-6, renovation note #1. The note indicates the 400 hz receptacle is 115 volt however, the panel schedule indicates the receptacle is connected to a 30 amp 3 pole circuit breaker. Please provide specification on the 400 hz receptacle.

A: Breaker should be 80 amp 3 pole. Receptacle type shall be Meltric Model DS100 Part# 33-94167-348-A188 with Self-Ejecting Connector Release or equivalent. 400Hz Receptacles shall be installed with Meltric Metal Box with Nylon Angle Part #31-9A053-080-112 or equivalent

2.05b Q: The note indicates to run a parallel set of conduits. Is the intent of the drawings to run two conduits and feeders from the panel to the receptacle? The detail on sheet E-10 indicates one conduit.

A: It will only be a single set of conduits. A parallel run will not be installed for the project.

2.05c Q: The note indicates 3 # 1 and 1 # 6 in a 1” conduit. The conductors indicated will over fill the conduit. The circuit breaker is 30 amp, would 3 #6 and 1 # 6 gnd be adequate?

A: Conduit size should be 1 ½”. Breaker size should be 80 amps for all 400Hz connections at panel “MSB”.

2.06 Q: Refer to sheet E-8, renovation note #1. The note indicates ¾” c with 3 #8, 1 #10 connected to a 150/3 circuit breaker. Is this the intent of the drawings?

A: The corrected note should be 1½” conduit with 3#1/0 and 1#6 ground to new 150 amp breaker.

2.07 Q: Refer to sheet E-11, renovation note #2. The note indicates 1 ¼” c with 3 #3, 1#8 gnd to be connected to 30 amp breaker and disconnect switch. Is this correct?

A: Yes, both disconnect switch and breaker shall be installed.

JFTB H1 PH2 ADDENDUM 2 P-4

2.08 Q: The new lighting fixtures on the fixture schedule are 277V. The new lighting circuits are being fed from 240V single phase and 208V 3-phase distribution panels.

A: This RFI was answered in Hangar 1 Phase 2 Addendum 1 Response to RFI’s 2.22.

END JFTB HANGAR 1 PHASE 2 ADDENDUM 2