RFI RESPONSES AMENDMENT 0003.PDF

Replace Michel Hall Transformer and Distribution Panels

Project # 4725286

HSCGG1-12-B-PFA028 AMENDMENT 0003

RFI #1. Is a generator enclosure required for the 200KW generator? There is no specification for one.

RESPONSE:

The generator requires a weather proof enclosure. The engine generator set enclosure shall be corrosion resistant, fully weather resistant, contain all set components, and provide ventilation to permit operation at rated load under secured conditions. Provide doors for access to all controls and equipment requiring periodic maintenance or adjustment. Provide removable panels for access to components requiring periodic replacement. The enclosure shall be capable of being removed without disassembly of the engine-generator set or removal of components other than exhaust system. The weatherproof enclosure shall have the generator tank mounted within the enclosure. The fuel fill line shall be accessible without opening the enclosure.

RFI #2. Can you clarify the number of conduits required from the switchboard to the generator?

Drawing E-401 shows 8 Drawing E-600 shows 4.

RESPONSE:

Provide a total of six conduits from the generator to the electrical room. Three 4" conduits will contain the generator power conductors to the switchboard. One 4" conduit will be a spare. One 2" conduit will contain the generator control wiring. One 2" conduit will contain the power conductors to the generator for block heaters, battery charger, etc.

RFI#3. Keynote 2 on Dwgs E100-400 and Note 1 on E401 call for the bidder to extend, modify or replace feeders and branch circuits 'as required'. In order for the bidders to be approaching this equally, Owner must identify what specific feeders and/or branch circuits need to be replaced. We acknowledge that some amount of branch jumpers or minimal feeder extensions at the panel location may be needed for the new panel connections. However, there is no information available to the bidders to lengths of wire are involved. None of the panel feeder or branch conduits are shown.

Alternatively, should the bidders include an allowance for this work? If so, please identify the amount to be carried.

Or, can we assume that all feeders and branch are in usable condition and properly sized, and that any concealed discrepancies or unsuitable wiring will be addressed as a change order on discovery? Please advise.

Refer to panel schedules on E-601 to E-605 and provide costs to extend all circuits for a particular panel.

RFI#4. Is it possible to extend the bid due date by at least one week, as at this time of year key people relied on for quotations are in varied stages of vacation, leave etc. also another USCGA project is scheduled to bid the same day as Michel Hall. A postponement will aid those parties planning to bid both projects.

REPONSE:

See amendment 0002.

RFI#5. E600 Keynote 8 calls for replacing the feeder wiring directly between Panel Main X-ray and Panel Dental X-ray, and removing the existing ECB. The connection at the main panel is shown as a tap off the line side of the main breaker. There is no indication of the existing conduit and wire size, or if any of that can be re-used. A potential problem exists with the connection shown at the main panel. If shown correctly, this may fall under the tap rule in the NES, and require a very expensive 400A feeder be run to the 150A dental X-ray panel. Please verify/confirm if this is the case and advise what may or may not be re-used from existing.

An alternate method would be to feed the Dental X-ray panel from a 150A branch breaker in the main panel. This would allow use of the ECB as a junction box and only jumpers within the ECB enclosure would be needed to reconnect the power, assuming it is sized correctly. The enclosure would remain without the breaker in it and a cover plate would need to be installed where the operating handle was.

Please review and advise what the bidders should allow.

RESPONSE:

E600 Keynote 8 calls for replacing the feeder wiring directly between Panel Main X-ray and Panel Dental X-ray, and removing the existing ECB. The connection at the main panel is shown as a tap off the line side of the main breaker. There is no indication of the existing conduit and wire size, or if any of that can be re-used. A potential problem exists with the connection shown at the main panel. If shown correctly, this may fall under the tap rule in the NES, and require a very expensive 400A feeder be run to the 150A dental X-ray panel. Please verify/confirm if this is the case and advise what may or may not be re-used from existing.

RFI#6. Dwg. E103 keyed note 5 calls for demo of exist UG1 and transformer, and its feeder back to panel LDP1, and to run a new feeder from LDP1 to new recessed panel UG1. One-line drawing E600 shows panel UG1 fed from panel PDP1. Please clarify which is correct.

RESPONSE:

Dwg. E103 keyed note 5 calls for demo of exist UG1 and transformer, and its feeder back to panel LDP1, and to run a new feeder from LDP1 to new recessed panel UG1. One-line drawing E600 shows panel UG1 fed from panel PDP1. Please clarify which is correct.

RFI#7. There is no transfer switch specified for the generator. Please confirm.

Power transfer from normal power to the emergency generator shall be accomplished with the electrically operated circuit breakers. Refer to keyed note 1, drawing E-600. In the event of normal power loss, the generator controller will open the main breaker and transformer breaker.

The generator controller will signal the generator to start. Upon starting of the generator, the electrically operated breaker for the generator will be closed by the generator controller. This will be accomplished in less than ten seconds.

Upon restoration of normal power, an adjustable timed relay (0 to 30 minutes) within the generator controller will restore normal power. This will be accomplished by a relay in the generator controller synchronizing the generator frequency with the utility power frequency. Upon synchronization, the generator electrically operated breaker will be signaled to open by the generator controller. The generator controller will then signal the electrically operated main breaker and transformer breaker to close.

RIF#8. E-001 Electrical Demolition Note #19 requires subcontractor to replace 'non-working' breakers (in the panels to be replaced under the bid option) with new ones 'in kind'. In order to price this, USCG must identify the specific manufacturer(s), quantities, types and ratings so pricing can be obtained, or alternatively, should an allowance be carried to cover this item? There is no way for a bidder to determine the scope of existing 'non-working' breakers from the information available. Please advise.

See panel schedules on drawings E-601 to E-605 for breaker quantities and size.

RFI#9. E-400 Keyed Note 4 - who is responsible to drain the fuel from the existing Generator tank, and is the fuel to be turned over to USCG? Please advise.

REPONSE:

Contractor is responsible for draining and disposing of the fuel.

RFI#10. Similarly, various notes on the plans and specifications inform the bidder that all demolished equipment, material, etc. is the property of the USCG and they may or may not elect to take possession of these items. On the big-ticket items, this will greatly affect the cost to be carried in the bid for disposal.

For the existing Generator, control panels, fuel tank and accessories being removed, is the contractor to dispose of this equipment, or will it be loaded on a flatbed and delivered to USCG on site? Please advise.

Contractor is dispose of all equipment as part of demolition.

RFI#11. Dwg.E-500 detail C2 shows a bonding jumper connected to the 'ATS' enclosure. There is no ATS per se shown on the plans or specified, but is the intent to connect this jumper to the new switchgear? If so please specify desired size of the conductor if this is the case.

The bonding jumper is to be connected to the switchgear enclosure and not and ATS.

RFI#12. E-500 detail C2 shows a single ground rod required per NEC 250-52. Where is this rod to be installed - there is none shown on E-401 within the existing building. Is this rod in addition to the triplex configuration shown just outside the building on E-401? If so, is it to be drilled thru the sub-basement floor? Or, is the triplex arrangement the only ground rods required? Please advise.

RESPONSE:

The triplex are the only ground rods required for service entrance grounding. Drilling into the floor is not required. The ground rods at the generator are required for equipment grounding.

RFI#13. E-401 indicates (2) unsized conduits connecting the new switchgear to the existing switchboard converted to a splice box - please identify the actual desired size and number of conduits intended to make these connections.

RESPONSE:

Instead of conduit, run a 3" deep, 24" wide ladder cable tray. Provide fire rated barrier at penetration at electrical room wall.

RFI#14. E-401 new conduit connecting panel PPE to the new generator is not sized. Should this be a 2" RSC conduit inside the building to be consistent with the callout on E-600, and should the callout of (8) 4" Schedule 40 PVC conduits in the ductbank on E-401 be changed to (7) 4" and (1) 2" conduit, or is the intent for (8) 4" and (1) 2"? Please advise.

RESPONSE:

The indoor conduit to panel PPE shall be 2". Provide a total of six conduits from the generator to the electrical room. Three 4" conduits will contain the generator power conductors to the switchboard. One 4" conduit will be a spare. One 2" conduit will contain the generator control wiring. One 2" conduit will contain the power conductors to the generator for block heaters, battery charger, etc. to panel PPE.

RFI#15. E-600 and E-401 do not call out the desired conduit size from the Existing MV Switch to the new 500kVA transformer. Please identify the conduit size desired.

Conduit from the MV switch to the 500kVA transformer shall be 2" RGS.

RFI#16. E-401 - no detail is given for the new 4" maintenance pads - are these required to be doweled into the existing sub-basement floor slab, or is a bonding agent required? If so, what prep is required on the existing floor? Also, is any reinforcing bar or mesh required within the housekeeping pad? Please advise.

RESPONSE:

Provide #5 dowels along the length the equipment every 2'OC. Along the length, one dowel 6" from the front of the pad and one dowel 6" from the rear of the pad. The dowels shall be imbedded 2" in the exiting slab and protrude 2" into the new pad.

RFI#17. E-500 detail B4 shows a 4/0 Tin Coated copper ground jumper connected from the ground ring to the Generator. E-401 calls for 3/0 bare copper ground wire throughout. Please clarify which is correct.

Also, no wire size is called out for the neutral bus to rod connection, in detail C2 - is this intended to be 3/0 bare copper? Please advise.

Provide 4/0 bare tinned copper ground wire to the generator.

RFI#18. Dwg E401 calls for (8)-4"PVC conduits from the Generator to the switchgear. Dwg E-600 calls for (3) 4" Conduit plus one (1) spare conduit for the power connection. Which is correct? Please advise.

RESPONSE:

Provide a total of six conduits from the generator to the electrical room. Three 4" conduits will contain the generator power conductors to the switchboard. One 4" conduit will be a spare. One 2" conduit will contain the generator control wiring. One 2" conduit will contain the power conductors to the generator for block heaters, battery charger, etc.