CADJ24-1029 RFIs and Answers_v2.docx

Prime Projects International

1. Reference to Statement of Work Item No. 4.2 Electrical:

Question: Please provide the manhole design that was not included in the RFP package, as mentioned.

Answer: Attached Question: Please clarify the type of 200kVA pad-mounted transformer - Is it Radial feed or Loop feed?

Answer: Radial Feed

Lac Assal Services

1. Secondary Load and Voltage Requirements:

Question: Could you please specify the secondary load (what size and number of breakers are needed?) and voltage requirements for the following equipment: Primary Power is 3 phase, 4160 V, secondary power will be 120/208 V (single phase/3 phase)?

Answer:

- 150KVA Secondary Distribution Centers (SDC) See the attached specification sheet for the SDC

- 200KVA Transformer (Use Only for the 400 HZ Convertor) The secondary side of the transformer will require insulated 800 KCMIL THHW wiring to a service disconnect rated for 520-540 AMPS, which will feed the 400 Hz converter.

2. Load and Voltage Requirements for Frequency Converter:

Question: Could you specify the load and voltage requirements for the 60Hz – 400Hz Frequency Converter?

Answer: The 400Hz Frequency Converter requires 208 Volts, 3 Phase, 150KW, 187.5 KVA.

3. Missing Manhole Design Attachment:

Question: Section 4.2.2 of the SOW states that the contractor shall follow the attached manhole design. However, no such attachment was included with the SOW. Could you please provide the missing attachment?

Answer: Attached

OMANG

1. Question: Please provide SLD (Single Line Diagram) for power cable distribution.

Answer: Still following up for an answer.

2. Question: From the provided site plan, we understand that the High Voltage Line (red color) is located between SDC19 & SDC20, and the Communication Hand hole-Fiber Line network (blue color) is shown only to illustrate the cable layout path and crossings. There is no modification required in this scope of work. Please confirm.

Answer: That is correct. The high voltage line and comm line are pre-existing and are shown to help the Contractor understand what utilities will be crossed.

3. Question: Please confirm that the supply of PSC (2 Nos) & SDC (4 Nos), including switchgear, is the contractor’s scope or will it be supplied by the government?

Answer: The PSCs and SDCs are to be provided by the contractor.

4. Question: Please confirm that the contractor’s scope is limited to the cable laying from PSC in the power plant to the 200 KVA Transformer through proposed Manholes (7 Nos). No further utility connections (like LV Power distribution, lighting, HVAC, etc.) are required.

Answer: Correct, the scope is for the installation of PSCs, SDCs, primary distribution line, manholes, 400 Hz converter, 200 KVA transformer, and secondary distribution line between the converter and transformer. It does not include lighting or HVAC.

5. Question: We understand that one PSC will consist of three (03) circuits to transfer the primary power (i.e., 2500 Ft x 3 = 7500 C). If this is correct, does the other PSC (shown in Site Plan) not require similar cable laying?

Answer: Only to the First Transformer (SDC) specifically for the Site.

6. Question: Will one PSC remain as a standby?

Answer: The second PSC will back feed the system.

7. Question: What is the purpose of two PSC units?

Answer: See the answer to question 6.

8. Question: Can the concrete pad for two PSCs be constructed as a single pad, or does it require a separate pad for each PSC?

Answer: Contractor's choice; however, the Contractor needs to follow manufacturer recommendations for spacing.

9. Question: Please provide the Precast Manhole Design.

Answer: Attached

10. Question: Please provide the details of Power Plant (supply to PSC).

Answer: Please See Electrical One-line

11. Question: Provide PSC and SDC recommended Manufacturer details along with Part No.

Answer: SDC and PSC specifications attached.

12. Question: The duct bank consists of 6 conduits that shall run from the power plant to MH4, with three conduits above and three conduits below. In this case, three circuits (2500 Ft x 3 Nos) shall run at the bottom side conduits. Similarly, from MH4 to MH7, there will be a duct bank of 4 conduits. In this case, three circuits (2500 Ft x 3 Nos) shall run as two at bottom side conduits and one at top side conduit. Please confirm.

Answer: No, the three cables shall be run in the same conduit. The extra conduits (5 between the power plant and MH4, 3 between MH4 to MH7) are to accommodate future growth and allow for new cable runs if a section of conduit collapses.

13. Question: Please clarify if any interface with the electrical automation and control system is anticipated in this SOW.

Answer: No, there will be no need for electrical automation within the SOW as it is not a requirement.

14. Question: After receiving the answers to the above queries, we will need a minimum of two weeks to receive prices from various suppliers. Hence, we request you to provide an extension of Two Weeks from the current submission date.

Answer: No

1. Question: Please confirm that the required PSC is 5 kV and SDCs are 150 kVA.

Answer: The PSC is rated for 15KV, for our service it is purposely de-rated to 5KV.

(The PSC features six (6) individual three-phase disconnects. Each connection point, referred to as a Ways, is rated for 600 amps and all are bussed together on one side. Each 600A connection point is an IEEE-386 Dead break. All power connections in or out of the PSC are through either 600A Dead break or 200A load break connections.)

2. Question: Are the PSCs Switchgear or Single Switch?

Answer: They are Switchgears.

3. Question: Provide the recommended manufacturers' options for 60-400 Hz Frequency Converter.

Answer: This is a Contractor-provided option.

4. Question: What is the secondary voltage for the 200 kVA transformer?

Answer: 208V, three phase, 400 Hz power needs to be outputted by the 400Hz converter. The 200 kVA needs to provide adequate power to the Hz converter with that output in mind.

5. Question: Is there any existing 5 kV switchgear with available spare for the 4160V feeder in scope?

Answer: Yes, with the PSC.

6. Question: Is the power source identified for the drainage sump pumps within each manhole?

Answer: No.

7. Question: Is the 40-600 Hz converter connected to the 200 kVA transformer?

Answer: Yes. The 200 KVA transformer is specifically called for to feed the 400 Hz converter.

8. Question: Please approve the extension request of a minimum of 2 weeks from the current date of submission.

Answer: See answer above.

Primary Switching Center (PSC)

1. Question: Please confirm that the total connected load will be 800kVA (4x150kVA SDC + 1x200kVA transformer).

Answer: High Voltage = 128.205 amps. (Currently getting clarification on this answer)

2. Question: Provide PSC incomer voltage and current details.

Answer: 4160V & 200 amps max load capacity.

3. Question: Confirm the number of PSC outgoing circuits - is it 4 or 1 each?

Answer: 4.

4. Question: If it is a Single Circuit, will cable tapping occur in every outgoing terminal? Please confirm.

Answer: No, at each Secondary Distribution Center (SDC) the termination point will be 200A 15kV Load break Elbow W/ Test Point.

5. Question: Does the scope of work require auxiliary cable from PSC to endpoint to avoid mid-terminal breakdown?

Answer: No

Secondary Distribution Center (SDC)

1. Question: Provide outgoing details of SDC.

Answer: SDC specifications sheet is attached. The SDCs can either have 4160V 3-phase primary power run through them or transform 4160V primary power to 120/208V US standard power.

2. Question: Do we need to consider separate cables for each SDC?

Answer: No

3. Question: Will cable sizes for SDC differ from the Transformer cable sizes? Please confirm.

Answer: No, all high voltage cable should be 15kV JCN 1/0 AWG AL Primary UD 133% EPR FN.

200KVA Transformer

1. Question: Provide outgoing details for the 200 KVA Transformer.

Answer: 200 kVA Transformer - 4160V Delta Loop Fed Primary - 208Y/120 Wye Secondary - NEMA 3R - Oil Cooled - 125°F Ambient Rated. The Secondary side of the Transformer will need to use insulated 800 KCMIL THHW size wiring to a service disconnect rated for 520-540 AMPS that will feed the 400 Hz convertor.

2. Question: Do we need to consider separate cable for this Transformer?

Answer: No, cable for the High Voltage side will be the same, “15kV JCN 1/0 AWG AL Primary UD 133% EPR FN. With Load Break Elbows”

3. Question: Provide the connection details/type from Transformer to Frequency Converter.

Answer: The Secondary side of the Transformer will need to use insulated 800 KCMIL THHW size wiring to a service disconnect rated for 520-540 AMPS that will feed the 400 Hz convertor.

400 Hz Converter

1. Question: Provide the required amperes for the Hz Converter.

Answer: 520-540 Amps will be fed in to the 400 Hz converter.

2. Question: Should the Converter be placed open or in a closed room? Please confirm.

Answer: The converter needs to withstand outdoor environmental effects.

4160V Cable:

1. Question: What will be the required type of cable – single core/3 core/4 core?

Answer: No, all high voltage cable should be 15kV JCN 1/0 AWG AL Primary UD 133% EPR FN.

2. Question: Provide the type of termination.

Answer: 200A 15kV Load break Elbow With Test Point.

Manhole:

1. Question: As per standards, the distance between two manholes should be 50 meters or less. However, a few manholes’ distances are more than 50 meters. Please provide the customer’s requirement.

Answer: The standard referenced is UFC 3-550-01. The section pertaining to manhole separation is 3-11.6, which allows for 120M separation. Can we check this info?

**Cosmezz Group**

1. SOW: pg. 4 par. 4.1.6 “The contractor shall pour four (4) concrete pads sized for 150 kVA Secondary Distribution Centers (SDC), 1 concrete pad sized for a 200 kVA transformer, 1 concrete pad sized for a 400Hz converter and two (2) concrete pads sized for Primary Switching Centers (PSC) at the locations specified by the BCE on the project site map.”

SOW: pg. 8 par. 4.2.6. “The Contractor shall place a 200 kVA transformer on a pad as outlined in section 4.1.6 at a location as indicated by the BCE.”

Question: The attached drawing indicates a transformer rating of 750kVA. Please confirm the correct transformer rating.

Answer: This was a mistake in earlier iterations of project development. The correct value is 200kVA.

2. Question: Please confirm this project will not require a US professional engineer to sign and stamp design documents.

Answer: That is correct, a US professional engineer is not required for this project.

3. SOW: pg. 8 par 4.2.4. “The Contractor shall place 4 SDC transformers on concrete pads poured by the contractor as outlined in section 4.1.6. The SDCs shall be centered on the pad with utility stub ups under the high voltage side of the SDC cabinet.”

Question: Please provide SDC technical requirements - rating.

Answer: The SDC technical specs are attached.

4. Question: Please confirm that an ACI certified concrete batching plant and USACE testing certified laboratory is a requirement for this project.

Answer: No, neither are required.

5. Question: Please confirm that the Project Manager, Construction Manager, Safety, and QC do not need to be US Nationals.

Answer: Correct, these positions are not required to be filled by a US national.

6. SOW (amendment): pg. 8 par 4.2.3. “The Contractor shall place one (1) Primary Switching Center (PSC) in the power plant as sited by the BCE.”

Question: Please confirm that PSC refers to medium voltage switchgear. Should this be a 3-way or 4-way switch? Please provide more information on PSC.

Answer:

- a) Please confirm that a canopy/shed for PSC, SDC, transformer, and converter is not a requirement.

Answer: Not a requirement.

- b) Please confirm that bollards (traffic protection) are not a requirement.

Answer: Not a requirement.