clarification lot c technical list no.01 sr. ref clause ... · ref clause / page description...

Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015

Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C

Sr.

No.Ref Clause / Page Description Bidders Query KETRACO response

1 Vol. 1 of 2;

Part 2: Employer’s

requirement;

Section IV: Bidding

Forms

67 For LOT C, in Price Schedule of

Lamu 400/220kV Extension, the

capacity of transformer is 1 X

90MVA 400/220/11kV

However Technical Data Sheet

describes the capacity (Page 167

of 206) as :

• Rated Power at site conditions

(ONAF2 or OFAF) – 450MVA

(150MVA/ph)

• Rated Power at site conditions

(ONAN) 240MVA (80MVA/ph)

Please clarify which one shall

The rated power shall be as follows:

• (ONAF) 90MVA

• (ONAN) 45MVA

2 Vol. 1 of 2;


requirement;

Section IV: Bidding

Forms

Price Schedule

for Lot C

According to ‘Lamu 400/220kV

Substation 400kV Single Line

Diagram’, there is no measuring

point.

But there is ‘Tariff Metering System’

in the Price Schedules of Lot C

Lamu 400kV. There is a Lot ‘220kV

– The Metering Panel (Two Panel)

Main & Backup Panel’ in the

‘Schedule No.1 Plant and

Mandatory Spare Parts from Abroad

– Item No 5.11’ and ‘Schedule No.2

Plant and Mandatory Spare Parts

from Abroad – Item No. 18.12’

Please confirm whether there is a

Lot ‘220kV – The Metering

Panel’?

If there is a Lot ‘220kV – The

Metering Panel’, which

measuring point should be?

Metering panel not required for 220kV.

3 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Substation

Control System

– Page…….

Substation Control System and

Telecommunications

Please make sure Lamu and

Hindi Substation using with SCS

or RTU? Please state the existing

Lamu 400/220kV Substation and

Hindi 220kV Substation Control

System or RTU and

Telecommunications

RTU at Hindi.

Lamu is not constructed, therefore for tendering pupose

bidders may assume SCS is installed.

Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT

Clarification Lot C Technical List No.01

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4 Vol. 1 of 2;


requirement;

Section IV: Bidding

Forms

Price Schedule

for Lot C

There is ‘Tariff Metering System’ in

the Price Schedules Lot C Nairobi

East. There are 4 Lots ‘400kV – The

Metering Panel (Two Panel) Main &

Backup Panel ‘ and 4 Lot ‘220kV –

The Metering Panel (Two Panel)

Main and Backup Panel’ in the

‘schedule No.1 Plant and


– Item 5.10 and 5.11’ and ‘Schedule

No.2 Plant and Mandatory Spare

Parts from Abroad – Item No. 18.11

and 18.12’.

But according to ‘Nairobi East

400kV Substation Single Line

Diagram’ there are 4 measuring

points. According to ‘Nairobi East

400/220kV Substation Single Line

Diagram’, there are 5 measuring

points.

A total of 9 measuring points in this

substation, that is 18 energy meters

and one ‘400kV – The Metering

Panel’ and two ‘220kV – the

Metering Panels’.

Please make sure the quantity of

the ‘400kV – The Metering Panel’

and ‘220kV – The Metering

Panel’.

There are 4 measuring point at 400kV and 5 measuring

points at 220kV.

5 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

12.5 -Metering

Cubicle

According to ‘Procurement

Documents Volume 2 of 2- 12.5.2’.

‘Main and Check meters may be

housed in the same cubicle’, but

there are ‘ The Metering panel (Two

Panel) Main & Backup Panel’ in the



– Item No 5.10 and 5.11’ and



– Item 18.11 and 18.12’

Please confirm that Main Checks

meters should be housed in one

metering cubicle or two?

One panel for 400kV and 2 panels for 220kV.

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6 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Appendix B Existing Telecom and OPGW

System

Having an overview of the

documents that we have

downloaded, we notice that the

Vol 2- Appendix B – Existing

Telecom and OPGW System is

missing

Information is attached in the addendum.

The following drawing shall be used for the purpose of the

tender:

A. Common for all Substation 1KHD636398

7 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Appendix A Plan and Sectional Tender

Drawings

Can you please provide plans

and sections of Lamu 400kV

Switchyard, Hindi 220kV

Substation and Koma Rock

220kV Substation?

Revised substation layout will be uploaded as addendum.

8 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Status of Substation Land Is the land requisition for Nairobi

East 400kV Substation site and

the resettlement on the

responsibility of the Employer or

not?

Yes.

9 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Clause 19.5 &

Clause 19.11

Water Supply for Substation In Clause 19.5, Volume 2 of 2 of

Lot C, water for the substation is

taken by drilling well, while

Clause 19.11 states that water for

the substation is from local tap

water. Please confirm the water

source for the substation.

When ever possible, the water shall be from the main

water supply source. However, in absence of the main

water supply pipe, bidders shall assume the well is

required. The provision of water shall be at the

Contractor's expense

10 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Nairobi

East/Lamu

Fire figthing Can you please confirm if water

fire-fighting system shall be

provided or not?

Water firefighting system shall not be used inside the

Control building.

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11 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Reactive Compensation for Auto-

Transformers

Please clarify the configuration

plan for reactive compensation of

Nairobi East 400kV Substation:

(1) whether the two circuits of

outgoing lines to Lamu require

high resistance (on the drawings

provided, each outgoing line is

with 100MVar parallel line of high

resistance)? (2) a 4×300MVA

transformer is added in the new

Nairobi East 400kV Substation,

for which only two voltage

classes of 400/220kV are

provided, whether a capacitor

shall be installed to compensate

the reactive loss of transformer?

Please clarify the installation

position and capacity.

Details are shown in the SLD and follow accordingly.

12 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Safety & Stability Control Device Design of the safety and stability

control device is related to the

systemic projects of the State

Grid of Kenya, which is not only

applicable to the new and added

substations in this bidding.

Please clarify whether the design

of safety and stability control

device is included in this scope of

bidding? If it is, in which Lot

included?

Clarification not clear.

13 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Appendix A Transformer Capacity At Lamu substation there is need

to construct another new

400/220kV transformer, whose

capacity is about 90MVA, but in

the TECHNICAL SCHEDULES

the capacity is 450MVA

(150MVA/ph), please clarify

which one is right?

Refer to item no. 2

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14 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Appendix A Transformer Capacity In new NAIROBI EAST

Substation the capacity of

transformer is 450MVA,but in the

TECHNICAL SCHEDULES the

capacity is 300MVA, please

clarify which one is right?

The 400/220/11kV Transformers shall be as follows:

• Rated (ONAF2 or OFAF) 300MVA (100MVA/ph)

• Rated (ONAN) 180MVA (60MVA/ph)

15 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Appendix A Drawing (Existing

Telecommunications and OPGW

System)

N/A The following drawing shall be used for the purpose of the

tender:

A. Common for all Substation 1KHD636398

16 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Appendix A i) Please provide us the distance

between Koma rock 220kV

substation and the Nairobi east

220kV substation, for we need to

evaluate the connection works of

the 220kV busbars.

ii) For Nairobi East 400/220kV

Substation, please provide us the

bay width of the 400kV and

220kV switchyard.

iii) For Nairobi East 400/220kV

Substation, is the 220kV

switchyard far away from the

400kV switchyard? where shall

be the control building located,

and also the staff quarter? there

is no overall plan of the whole

substation.

i) and ii) Refer to tender drawings as specified in item 15.

Howerver it’s the responsibility of the Contractor to design

the substations.Bay width shall be determind by

Contractor.

iii) The sizes of the proposed buildings are indicated in the

tender specification and schedule no. 4 of the price

schedules. The contractor to propose a suitable

location and this shall be shown in the proposed bid

drawings.

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17 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Clause No. 1.4 The terminal points, the

connections between the 400kV

terminal towers and the

substation gantry structures are

included in Lot C, but we have

checked the bidding document of

Lot A, Clause 1.4, the

connections has been divided

into the work scope of Lot A. so

the two documents are conflicting

with each other. in our opinion,

the connections shall be in the

work scope of transmission

line(Lot A), please clarify.

The connections for the transmission lines scope is right

upto the gantries. The down droppers and clamps shall be

provided by the substation contractor. The bonding of the

ground wire to the substation earth grid shall be

responsibility of substation Contractor.

18 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Price Schedule

for Lot C -

Nairobi East

Substation

Item 11.1, Item 10.5, Item 10.6 The quantity these equipment in

the Price Schedule and the

bidding drawings are

contradicting. Please clarify.

Price schedule is corrected and revised schedule is

attached in the addendum.

19 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Price Schedule

for Lot C -

Nairobi East

Substation

Please clarify the different

application of the price schedule

Item 26.8(Substation perimeter

fence including security) and Item

26.9(Substation perimeter fence).

26.8 is the Substation perimeter fence with the security

system - security camera connected to Control Center in

Nairobi

26.9 Second layer fence.

20 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Price Schedule

for Lot C -

Lamu 400kV

Substation Ext.

Item 1.3, Item 1.4, Item 1.6, Item

2.3, Item 2.11, Item 2.13

The quantity these equipment in

the Price Schedule and the

bidding drawings are

contradicting. Please clarify.

Price schedule is corrected and revised schedule will be

uploaded in the addendum.

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21 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Clause 1.2.2 The substation work at Lamu 400kV

will comprise the followings:

i. Extension of existing 400 kV

switchyard to accommodate a

transformer feeder bay

ii. Supply, install and commission

One (1) 400/220 kV 90 MVA

transformer

iii. Supply, install and commission

Two (2) x 100 MVAr line connected,

switchable shunt reactors on

Nairobi East 400kV OHL lines.

But after we checked the Price

Schedule of Lamu, we found that

there are several item that should

not in the scope of Lot C, we

think these items shall be

conducted by others. Please

clarify. These items are listed

below for your reference.

Item 26.8 Substation perimeter

fence including security

Item 26.13 Substation gatehouse

Item 26.14 Substation control /

relay building

Item 26.17 Sewage System

Item26.18 Carpark

Item31.6 Single Unit staff house

Item31.7 Double Unit staff house

Item31.9 Access road outside the

sub station

and also, for the items these are

not listed here , we assume that

we only conduct the works

related to the 400/220kV

transformer and the 400kV shunt

reactors.

These are required. However price schedule is revised

and will be uploaded as addendum.

22 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Clause 1.6 (G) Wind Load “For design purposes a basis

wind speed of 39m/s shall be

assumed.”

Please confirm our following

understanding:

According to IEC-60286, the

basis wind speed of 39m/s is the

10-min wind speed at 10m above

ground and with a 50-year return

period.

The Basic Wind Speed 39m/s is the 3s gust. This has to

be converted to Reference wind speed i.e into 10-min

average speed.

23 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Substations mentioned in Lot A

and Lot B are not in accordance

with substations mentioned in Lot

C, please clarify it. There are two

overhead feeders to ISINYA, and

is ISINYA included in Lot C?

From Nairobi East 400kV, there are: 2 x 400kV OHL to

Lamu and 2 x 400kV OHL to ISINYA. The description on

the Lot A and B to be corrected.

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24 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

The bid document mentioned that

the 220kV busbar of NAIROBI

EAST should be joint to KOMA

ROCK 220kV busbar, then how?

Is this part included in Lot C? If it

is, please provide the layout of

the two substations.

The existing KOMA ROCK substation is construted by

others and it is not part of Lot C scope. Revised

substation layout will be uploaded as addendum.

25 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Price Schedule

for Lot C -

Lamu 400kV

Substation Ext.

Item 10.1 Please clarify the item of 10.1

mentioned in Price

Schedules_Lot C_Lamu

400kV.xls is correct or not.

No requirements for new LVAC board. Revised price

schedule attached.

26 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

The manufacturer lists and the

information of control and

protection devices in extension of

existing substation.

The existing substations (Lamu 400kV and 220kV Koma

Rock) are not constructed yet and thus this information is

not available.

27 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

If there is any difference required

in the BOQ, technical

requirements, drawings, such as

the quantity and capacity of the

power transformer, which

requirement could we follow?

Where there are descrepancies please clarify.

28 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Short-circuit current: It is 50kA for

400kV and 40kA for 220kV in

Section J of Schedule of

Technical Particulars, but we

think 40kA for 400kV and 31.5kA

for 220kV is enough

(because this is the HV

equipment requirement), please

clarify.

Please comply as required.

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29 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

The 400kV transformer type in

LAMU substation: In TECHNICAL

SPECIFICATIONS and

Price Schedules_LotC_Lamu it is

auto-transformer, but for tender

drawing legend, it is an

ordinary three-phase transformer

but not auto-transformer. Please

clarify.

It's Auto-Transformer. The revised SLD will be uploaded

in the addendum.

30 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

400kV Disconnector type:

According to the attachment

drawings, the disconnector is

horizontal center break type.

Whether can it adopt three-

column horizontal rotary

disconnectors.

The information shown in the tender drawings are for

tendering pupose only. The offerered plant items shall be

inline with the requirements in the specifications.

31 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Earthing conductor size: It is said

“Main earthing system shall

comprise complete set of copper

tapes (300 mmsq)” in Section 7

of Price Schedules, we think the

earhing conductor size should be

calculated based on IEEE 80 and

submitted to owner for approval

but not confirmed 300 mmsq

now. Please clarify.

For the purpose of the tendering please use the size

specified.

32 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

In Price Schedules_Lot C_NE,

the 220kV CT quantity maybe

changes from 21 to 24.Please

clarify.

In Price Schedules_LotC_Lamu,

the quantity of 400kV

Disconnector with one earth

switch maybe changes from 2

to7, and the quantity of 400kV

Disconnector with two earth

switches

Maybe changes from 3 to 0.

Please clarify.

Price schedule is corrected and revised schedule will

uploaded as addendum.

33 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

In Lamu SLD " PE " equipment is

shown which is not available in

the price schedule. Please clarify

this item.

SLD is corrected and revised SLD will be uploaded in the

addendum.

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34 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Please provide the soil resistivity

and soil bearing capacity value ,

water table level of Nairobi east

substation.

The bidders shall assume the conditions based on their

experience and hence the reason for the site visits. Soil

resistivity and soil bearing capacity value , water table

level measurements is part of the design scope of the

contractor.

35 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Please provide the plot area

available for constructing the

proposed green field substation.

The available plot area is approximately 1500m x 300m.

The proposed substation footprint for 400kV and 220kV is

given in the tender drawings.

36 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Please provide the overall plot

plan indicating the location of

control room, DG building (if

any), gate house , staff housing

units, store , control room.

Bidders shall propose the plan as per the requirement in

the Technical Specification and bid documents. The

design of substation including the layout plan is part of

Contractor's scope.

37 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Kindly provide survey details in

the form of contour level or in the

form of .CSV file and site co-

ordinates for layout boundaries

Bidders shall undertake this work upon contract award.

For the purpose of the tendering the bidders shall assume

based on their experience. This will be part of contractors

scope.

38 Vol. 2 of 2;


requirement;

Section VI:

Technical

Specifications For

Substation and

Overhead Line

Termination

Please provide us the details of

rooms required for the control

room.

The bid documents are clear on the requirements

10 of 33



Sr.




39 Lot

C_Appendix

C.1_schedule 1

of Technical

Particulars_NE

ast_Rev 1,

Page 45 of 206

Please furnish the Rated Voltage

– MOA of 220kV surge arrester.

As per Bidding Document Volume 2 of 2, Section VI,

Technical Specifications , section 7.1 paragraph 1 Bidders

are expected to carry out insulation studies which will

produce the required surge arrester characteristics. For

the tendering purpose the bidders shall propose a

standard rating e.g. 198kV.

40 Lot

C_Appendix

C.1_schedule 1

of Technical

Particulars_NE

ast_Rev 1,

Page 193 of

206

Please furnish the discharge

current of 108kV, Class 4

lightning arrester to be mounted

near the neutral reactor.

For the tendering purpose the bidders shall propose a

standard rating.

41 Price schedule

1 Quantity

mismatch KET-

2014-D-

001_Nairobi

East 400kV

SLD &

Protection Rev

3

As per price schedule 1 item 10.5

Earthing transformer - 3 Nos

As per SLD


As per layout


Please confirm the actual

requirement.



42 Price schedule

1 Quantity

mismatch KET-

2014-D-

001_Nairobi

East 400kV

SLD &

Protection Rev

3


Neutral earthing resistor - 3 Nos

As per SLD

Neutral earthing resistor - 4 Nos


requirement.



43 Price schedule

1 Quantity

mismatch KET-

2014-D-

001_Nairobi

East 400kV

SLD &

Protection Rev

3


Bank of 3 Nos of 100 MVA single

phase autotransformer - 3 Nos

As per SLD


phase autotransformer - 4 Nos

As per layout


phase autotransformer- 4 Nos


requirement.



11 of 33



Sr.




44 Price schedule

1 Quantity

mismatch KET-

2014-D-

001_Nairobi

East 400kV

SLD &

Protection Rev

3

As per price schedule 1 item

12.12

Externally mounted CT's for 3 x

Interbus transformer bays

As per SLD

Externally mounted CT's for 4 x

Interbus transformer bays


requirement.



45 Price schedule

1 Quantity

mismatch KET-

2014-D-

001_Nairobi

East 400kV

SLD &

Protection Rev

3

As per price schedule 1 item

12.13

11kV AIS busbar - 3 Lots

As per layout

11kV AIS busbar - 4 Lots


requirement.



46 Price schedule

1 Quantity

mismatch KET-

2012-D-002

Nairobi East

220kV SLD

Rev 2


220kV Single phase current

transformer - 21 Nos

As per SLD

220kV Single phase current

transformer - 24 Nos


requirement.



47 Price schedule

1 Quantity

mismatch KET-

2014-D-

001_Nairobi

East 400kV

SLD &

Protection Rev

3


Transformer fire wall - 3 Lots

As per SLD

Transformer fire wall - 4 Lots


requirement.



48 Price schedule

1 Item Nos :

1.12

1.13

1.14

& 400kV SLD

KET-2014-D-

001 Rev 3

As per price schedule 1

Metering core is 0.5, Protection

core is with 3P

As per SLD

Metering core is 3P/1.0,

Protection core is with 3P

Please confirm whether metering

core shall be 0.5 or 3P/1.0.

Class 1.0 shall be provided. Revised schedule will be


49 Price schedule

1 Item Nos :

2.12 & 220kV

SLD KET-2014-

D-002 Rev 2


Metering core is 0.5, Protection

core is with 3P

As per SLD

Metering core is 3P/1.0,

Protection core is with 3P

Please confirm whether metering

core shall be 0.5 or 3P/1.0.

Class 1.0 shall be provided. Revised schedule will be


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Sr.




50 Price schedule

1 Item no : 2.5

& Technical

schedule page

45 of 206


220kV lightning arrester- Class 3.

As per tech schedule 1

220kV lightning arrester- Class 4.


requirement.

Class 4 shall be offered.

51 Price schedule

1 Item nos:

1.15 , 2.13 ,

220kV SLD

KET-2014-D-

002 Rev 2

,400kV SLD

KET-2014-D-

001 Rev 3,

Section VI

clause 5.2,

page 81 of 385


Metering class accuracy of

current transformer in combined

CT/VT unit- 0.2

As per SLD



CT/VT unit- 0.2s

As per specification



CT/VT unit- 0.2s


requirement.

Shall be 0.2s. (Also applicable for Lamu and Hindi)

52 Section VI

clause 5.2,

page 81 of 385

& 220kV SLD

KET-2014-D-

002 Rev 2

As per specification it is stated as

"Tariff Metering shall be provided

on each incoming 220kV line".

But in SLD, tariff metering is also

provided in 220kV transformer

incomer feeders. Please clarify.

Please comply as required.

53 Price schedule

1 item no : 2.12

As per price schedule 1, 50VA for

each winding to be provided for

220kV inductive voltage

transformer. Since it is a two

winding transformer, 100VA is

sufficient. But price schedule 1

calls for 150 VA. Please clarify.

50VA for each winding shall be provided. For 2 winding

100VA is accepted.

54 Section VI -

Technical

specification,

clause 14.35,

page 272 of

385 - Auto

transformers

As per specification, no fire

protection is required for

transformers.

Hence we are not envisaging any

provisions in the transformer for

fire protection. Please confirm.

Correct.

55 Lot

C_Appendix

C.1_schedule 1

of Technical

Particulars_NE

ast_Rev 1,

Page 168 of

206

The tertiary winding capacity is

given as 70 MVA in transformer

technical datasheet. We find this

value to be very high when the

transformer tertiary is going to be

loaded with 500 kVA Auxiliary

transformer. Please confirm the

correctness of the value.

The minimum rating of the tertiary winding shall be at least

1/3 of the transformer main winding MVA rating.

13 of 33



Sr.




56 Lot

C_Appendix

C.1_schedule 1

of Technical

Particulars_NE

ast_Rev 1,

Page 165 of

206 & 400kV

SLD KET-2014-

D-001 Rev 3

As per technical schedule

autotransformer is said to be with

stabilising tertiary winding but as

per SLD, tertiary winding is to be

loaded. Please clarify.

The tertiary winding shall be utlised for auxiliary/earthing

transformer for local LVAC supply.

57 Price schedule

1 Item 7.1 &

Section VI -

Technical

specification,

clause 3.4,

page 47 of 385

As per price schedule 1 "Main

earthing system shall comprise

complete set of copper tapes

(300 sqmm)," is given.


" The use of bare, stranded,soft

drawn copper is preferred by

KETRACO."

As per datasheet, bare copper

conductor , lead sheathed copper

conductor, copper flat bars

Please confirm which one to be

followed whether copper flat or

stranded bare copper conductor

or lead sheathed copper

conductor for below ground

earthing.

Both accepted. Please refer to item no. 31.

58 Price schedule

1 Item 7.1 &

Section VI -

Technical

specification,

clause 3.4,

page 47 of 385

As per price schedule 1 "Main

earthing system shall comprise

complete set of copper tapes

(300 sqmm)," is given.


" The use of bare, stranded,soft

drawn copper is preferred by

KETRACO."

As per datasheet, bare copper

conductor , lead sheathed copper

conductor, copper flat bars

Please confirm which one to be

followed whether copper flat or

stranded bare copper conductor

or lead sheathed copper

conductor for above ground

earthing.

Refer to item 57 above.

14 of 33



Sr.




59

Section VI -

Technical

specification,

clause 17,

page 311of 385

& Appendix A


" The resistors shall be rated for

10 seconds and the current

ratings and ohmic value shall be

as shown in the drawings in

Appendix A. The neutral earthing

arrangement shall be as per

requirement indicated in drawings

(Appendix A)." But in the

drawings provided in Appendix A

does not show the requirement of

the neutral earthing resistor and

the neutral of earthing

transformer is solidly earthed.

Please revise the drawings and

provide the necessary current

rating and ohmic value of neutral

earthing resistor in the drawing.

NER is required. Revised drawing will uploaded as

addendum.

60 Section VI -

Technical

specification,

clause 16.1,

page 307of 385

Lot

C_Appendix

C.1_schedule 1

of Technical

Particulars_NE

ast_Rev 1,

Page 196 of

206

Lot

C_Appendix

C.1_schedule 1

of Technical

Particulars_NE

ast_Rev 1,

Page 207

Please clarify the requirement for

Limitation and withstanding of

fault current in neutral about

Earthing Transformers.

As per earthing transformer

specification , it is mentioned

that” Earth fault current required

Amp. 1050”、 “Earthing/auxiliary

transformers shall be capable of

withstanding for a period of 30

seconds”.

As per earthing transformer

technical schedule it is

mentioned that” Limitation and

withstanding of fault current in

neutral for 30s:1050A”.

However, as per neutral earthing

resistor technical schedule, The

resistors limitation and

withstanding of fault current is

500A for 10s.

Comply as required.

61

Price schedule

1 Item nos :

1.13 ,

As per price schedule 1 , busbar

inductive voltage transformer Qty

is 2 Nos. (1 No. per

busbar)

As per SLD, Busbar Inductive

voltage transformer is

represented as 3 x

400V/Sqrt(3)/110V/Sqrt(3).


requirement.

Shall be 1 x Single Phase with 2 windings.

15 of 33



Sr.




62

Price schedule

1 Item no : 11.3

& 400kV SLD

KET-2014-D-

001 Rev 3

As per price schedule 1, one set

of bushing CT has to be provided

for neutral reactor protection.

Please clarify whether the CT

shown in SLD near neutral

reactor is bushing type or outdoor

post type.

Bushing type.

63 KET-2014-L-

104_Nairobi

East 400kV

Layout &

Elevation Rev

2

KET-2014-L-

105_Nairobi

East 220kV

Layout &

Elevation Rev

2

Section VI -

Technical

specification,cl

ause 19.17.16,

page 361 of

385

We noticed a discrepancy

between the drawings in annex

and the specification :

It is specified 7,3m for major

access road (we understand for

heavy roads) and 5m for access

road (we understand other roads

than heavy ones).

In the drawings and according to

the scale, roads are shown of 5m

for heavy roads and main access

roads and of 3m for other ones.

Please confirm that we can

consider 5m for heavy roads and

3m for the other ones.

5m for heavy or main access/perimeter roads in the

substation and 3m for maintenance access, as shown in

the layout drawings.

64 Section VI -

Technical

specification,cl

ause 18, page

312 of 385

Please clarify whether diesel

generator has to be placed in

separate building.

Outdoor type/design with noise enclosure shall be

provided. Bidders shall propose in the bid submissions.

65 Section VI -

Technical

specification,cl

ause 1.6, page

4 of 385

We presume that the maximum

wind speed of 140km/hr given in

specification is 3s gust wind

speed. Please confirm.

See item no. 22

66 Section VI -

Technical

specification,cl

ause 1.6, page

4 of 385

Please confirm whether the Ice

Loading details are applicable? If

so please clarify the weight of Ice

to be considered per meter.

No.

67 General Please clarify whether staff

housing units and store are

located outside the substation or

inside the substation.

Outside the switchyard area but within the substation

land.

16 of 33



Sr.




68 400kV SLD

KET-2014-D-

001 Rev 3

There is no switch between the

auto transformer and auxiliary

transformer. So the failure of

auxiliary transformer will cause

the trip of the CB at HV side of

auto transformer and enlarge the

accident. So we suggest that a

falling type safety fuse should be

set between the auto transformer

and auxiliary transformer,

then, the main transformer will

not tripped if there is only some

fault with the auxiliary

transformer, which will make the

grid more stable.

Please follow to the requirements in the tender.

69 KET-2012-D-

002 Nairobi

East 220kV

SLD Rev 2

As per the 220KV Single line

diagram, 220KV busbar rating

specified as 2000A, but the CT

rating specified as 2500-1500/1A.

Please confirm / clarify 220kV

Busbar rating and CT rating.

Please follow to the requirements in the tender.

70 Section VI -

Technical

specification,cl

ause 4.2.4.3,

page 59 of 385

As per specification, shunt

reactor circuit breakers are to be

provided for special duty

applications based on point on

wave scheme. Hence , please

clarify whether point on wave

relay is exclusively required for

these breakers or pre-insertion

resistor can be used. Price

schedule does not call for any of

these items.

No. Please follow to the requirements in the tender.

71 General Please provide us the initial

Tension on 400kV & 220kV

Phase conductors and shield wire

for tower design

Bidders shall use their experience and engineering

knowledge to determine this.

72 Section VI -

Technical

specification,

Civil works.

clause 19.7.16,

page 361of 385

Kindly confirm whether the

dimension & type of the road,

within the compound of staff

housing, could be considered as

3m & concrete road respectively.

5m and concrete/tarmac road.

17 of 33



Sr.




73 Lot

C_Appendix

C.1_schedule 1

of Technical

Particulars_NE

ast_Rev 1,

Page 169 &

PAGE 4 of 206

As per transformer technical

datasheet ,page 169 the short

circuit

currents are defined as :

- 50kA/2s for HV terminals and

windings (400kV)

According to the general

datasheet and SLD

- 40kA/1s for 400kV switchgear

Please clarify : what is the short-

circuit current to be taken

into account for 400kV terminals

and windings of transformer?"

For Transformer: 50kA/2s for HV terminals (i.e. the

Bushings)

74 Lot

C_Appendix

C.1_schedule 1

of Technical

Particulars_NE

ast_Rev 1,

Page 169 &

PAGE 25 of

206

As per transformer technical

datasheet ,page 169 the short

circuit

currents are defined as :

- 40kA/2s for LV terminals and

windings (220kV)

According to the general

datasheet and SLD

- 31.5kA/1s for 220kV switchgear

Please clarify : what is the short-

circuit current to be taken

into account for 220kV terminals

and windings of transformer?"

For Transformer: 40kA/2s for HV terminals (i.e. the

Bushings)

75 General Please provide the capacitance

value of 400kV and 220kV CVT

For tendering purpose the bidders shall propose a

standard/typical value. (Applicable for all Substations

under Lot C)

76 General Please specify the number of

spare feeders to be considered in

LVAC switchgear.

For tendering purpose the bidders shall offer 2 spares on

each section of the busbar.

77

----

Kindly provide the design factor

of safety for normal condition and

short circuit force condition for

the design of substation steel

structures.Or else specify the

standard of practice to be

followed for the same.

This shall be in accordance to the international standards

(e.g. IEC) as specified in the tender documents.

78 General

Topographic

Survey

Drawing

Please provide us the

topographic survey drawing for

all three(3) substation in order to

have a general information to

calculate earthworks quantity that

will be involved for substation

platform preparation.

The bidders shall be guided by the findings of the site

visit. Topographic survey is part of contractor's scope.

18 of 33



Sr.




79 Remote end

scope of works -

Protection and

telecommunicat

ion

We presume that there is no

remote end scope of work in the

following substations:

1. Isniya -1&2

2. Lamu -1&2

3. Embakasi

Please confirm.

No remote end works at Isinya and Embakasi. Works at

Lamu shall be covered under Lamu Extension scope.

80 Appendix D.1,

Schedule No.1,

Item No.5, 5.8

Please furnish the make,type and

location of NCC and RCC.

Refer to item No. 6

81 Appendix D.1,

Schedule No.1,

Item No.3,

400kV

Protection

system, 3.1,

Overhead line

feeder

protection

Lot C_Tech

Spec_Section

V, Clause

8.2.1.2,

400/220kV

Overhead Line

Feeders, C

Main

protection,

Please provide the make and

type of Main -2,Numerical current

differential relays for the following

lines to be matched with remote

end:

1. Isniya -1

2. Isniya -2

3. Lamu-1

4. Lamu -2

Information on remote end protection is currently not

available, therefore for the purpose of the tendering

bidders shall propose a suitable type/make as specified

the technical schedule.

82 Appendix D.1,

Schedule No.1,

Item No.4,

220kV

Protection

system, 4.1,

Overhead line

feeder

protection

Lot C_Tech

Spec_Section

V, Clause

8.2.1.2,

400/220kV

Overhead Line

Feeders, C

Main

protection,

Please provide the make and

type of Main -2,Numerical current

differential relays for the following

lines to be matched with remote

end:

1. Embakasi

Refer to item 81.

19 of 33



Sr.




83 Appendix D.1,

Schedule No.1,

Item No.3,

400kV

Protection

system, 3.3

Transformer

protection

Lot C_Tech

Spec_Section

V, 8.2.1.4

400/220kV

Auto-

transformers

(400kV side),

C. Auto-

Transformer

protection.

As per price schedule,

As per technical specification,

Main - 2 shall be of High

impedance 3-winding transformer

differential protection with

stabilizing resistor and metrosil.

Please provide the datasheet for

the same.

Proposed data for High Impedance :

1) Relay Type - High Impedance

2) Relay Operating Principle - Voltage or Current

3) Relay Operating Time < 40ms

4) Metrosil Available - Yes

5) Stabilizing Resistor Available - Yes

Revised data sheet will be uploaded as addendum.

84 Appendix D.1,

Schedule No.1,

Item No.4,

220kV

Protection

system, 4.1,

Overhead line

feeder

protection.

Lot C_Tech

Spec_Section

V, Clause

8.2.1.2,

400/220kV

Overhead Line

Feeders, h.

Autoreclose

Lot

C_Appendix

C.1_Schedule

of Technical

Particulars_NE

ast_Rev 1_25-

05-

15,D.Protection

and indication

system.

As per price schedule and

technical specification, auto

reclose and undervoltage relay

should be a separate relay.

But in technical datasheet, auto

reclose and undervoltage is a

part of main protection distance

and line differential (21/87L).

Please confirm whether the auto

reclose and undervoltage relay is

integrated function or seperate

relay.

Should be separate.

20 of 33



Sr.




85 Appendix D.1,

Schedule No.1,

Item No.3, 3.3

Transformer

protection.

KET-2014-D-

001_Nairobi

East 400kV

SLD &

Protection Rev

3

In price schedule, Main-1

protection of transformer is

numerical 3- winding biased

transformer differential protection.

As per SLD, only 1 CT core is

allocated at HV side and LV side

each. There is no CT core at

Neutral end. For 3-winding

differential protection, one more

CT core should be placed at

Neutral end.

Please confirm whether the main -

1 protection is 2 winding

differential protection or 3 winding

differential protection.

2 CTs at HV & LV winding are also sufficient for protection

of the transformer.

Proposed to maintain as Main 1 as 2 winding differential.

86 Appendix D.1,

Schedule No.1,

Item No.3, 3.2

Tie protection

and 3.3

Transformer

protection.

Lot C_Tech

Spec_Section

V, Clause

8.2.4.1,

400/220kV

Auto-

transformers

(400kV side), d.

400 kV HV

connections

protection.

As per price schedule, stub

protection is required.


High voltage connection (HVC)

protection is required.

Please confirm whether both the

protection are same.

No. Stub Protection is for the Tie Bus. Stub Protection

shall be used for OHL bay while HVC shall be used in

Transformer bays.

21 of 33



Sr.




87 Appendix D.1,

Schedule No.1,

Item No.3, 3.3

Transformer

protection.

Lot

C_Appendix

C.1_Schedule

of Technical

Particulars_NE

ast_Rev 1_25-

05-15, D.

Protection and

indication

system, Main

transformer /

Reactor biased

differential

protection 87

As per price schedule,

As per technical datasheet, REF

for HV, LV is an integrated

(inbuilt) feature for main

transformer biased differential

protection 87.

Hence there is no separate REF

relay required.

Please confirm whether the

understanding is right.

If seperate relay is required

please update the same in price

schedule.

Yes, correct.

88 KET-2012-D-

002 Nairobi

East 220kV

SLD Rev 2

Appendix D.1,

Schedule

No.1,Item No. 5

SCS,

Telecommunic

ation &

associated

equipment,

220kV Indoor

Control Panels.

As per SLD, Circuit breaker

cubicle shall be 8 Nos.

As per price schedule, 220kV

Circuit breaker cubicle is of 6

Nos.

2 Nos of tie circuit breaker

cubicles are missing in price

schedule.

Please update the same in the

price schedule.

Price schedule revised and will be uploaded as

addendum.

89 Lot C_Tech

Spec_Section

V,Clause 14,

Power

transformer

Please confirm the insulation

class of auto transformer.

Please refer to IEC 60076 and comply accordingly.

22 of 33



Sr.




90 Lot C_Tech

Spec_Section

V,Clause 15,

Shunt Reactor,

15.2.3, Neutral

earthing.

KET-2014-D-

001_Nairobi

East 400kV

SLD &

Protection Rev

3


neutral earthing shall be directly

connected to earth.

But as per SLD and requirement,

the neutral shall to earthed via a

Neutral Grouding Reactor (NGR).

Please confirm.

The drawing is revised and will be uploaded as

addendum.

91 KET-2014-D-

001_Nairobi

East 400kV

SLD &

Protection Rev

3

Lot C_Tech

Spec_Section

V,Clause 16,

auxiliary/earthin

g transformers.

Please confirm whether the 11kV

side of auxiliary/earthing

transformer shall be directly

earthed or earthed via a resistor.

Earthed via NER.

92 Lot C_Tech

Spec_Section

V,Clause 11,

LV service

equipment,

11.2, Scope of

works

Lot

C_Appendix

C.1_Schedule

of Technical

Particulars_NE

ast_Rev 1_25-

05-15, I. LV

services

equipment, 1.

110V DC

system-

substation

services

supply.

As per specification, minimum

discharge capacity of 110VDC is

400AH.

As per datasheet, minimum

discharge capacity is 250Ah.

Request you to confirm the exact

value so that every bidder will be

in the common platform.

For the purpose of tendering the bidders shall consider

400AH.

23 of 33



Sr.




93 Appendix D.1,

Schedule No.1,

Item No.3, 3.3

Transformer

protection.

We presume that guard

protection is transformer

mechanical protection like

(bucholz, PRV, oil temperture

indictor, winding temperature

indicator etc..)

Yes, correct.

94 Lamu Lot

C_Appendix C

2_Schedule of

Technical

Particulars_La

mu 400kV

ExtPage 164 of

206 & KET-

2014-D-303

Lamu 400kV

SLD REV 2

In Transformer technical

datasheet, it is mentioned as

single phase auto transformer

with vector group YNa0d but in

SLD the representation is shown

as power transformer.

Please clarify whether it is auto

transformer or power transformer

and also whether it is single

phase transformer or 3 phase

transformer.

See item no. 29.

95 Lamu Lot

C_Appendix C

2_Schedule of

Technical

Particulars_La

mu 400kV Ext

Page 164 of

206

In transformer technical

datasheet altitude is given as

1600m but altitude of lamu

substation is 216m. Please

confirm and revise the technical

schedule .

Lamu is 216m and revised schedule will be uploaded.

96 Lamu Price schedule -

4 , Item : 26.14

As per civil works price schedule -

4, substation control/relay

building to be provided with area

40m x 32m. Lamu is an already

existing substation and hence we

presume control building is

already existing and the same

shall not be considered in present

scope. Please confirm whether

our understanding is correct.

Incase control building is required

to be constructed , please

provide the details of individual

rooms in the control building.

Bidders shall include new control building as required in

the price schedule.

97 Lamu General We presume space for control

and protection panels for the

proposed extension is already

available in the existing control

room. Please clarify.

Refer to item 96.

24 of 33



Sr.




98 Lamu Price schedule

1 Item 7.1

"Main earthing system for the

complete substation:- Substation

underground earthing system

with rating of 40kA, 1 Sec for

400kV and 31.5kA, 1 Sec for

220kV."

We presume main earth mat is

already existing and 400kV

equipment earth risers alone

considered in present scope. No

earthing works is considered in

220kV system. Please confirm.

Earthing would be only required for the extented portion

and shall interface with existing gird.


1 Item : 1.14

As per price schedule, it is

mentioned as " Post type

(400/Sq3)kV/(110/sq3)V

(phase‑to‑neutral) (1-Phase) 2-

winding capacitor voltage

transformers with 2 no. of Class

3P for protections and 1 no. of

Class 0.5 for instrument/BCU

with rated output 100VA per

phase (50VA for each winding) "

Since it is a 2 - winding CVT, 1

no. of class 3P and 1 no. of class

0.5 shall be provided. Please

confirm.

Correct.


1 Quantity

mismatch


400kV Disconnector, motorised

(3-phase) 4000A complete with

one integral motorised earth

switch - 2 Nos

As per SLD



one integral motorised earth

switch - 7 Nos


requirement and update the price

schedule.

Refer to item 32.

25 of 33



Sr.





1 Quantity

mismatch




two integral motorised earth

switches - 3 Nos

As per SLD




switches - 0 Nos


requirement and update the

price schedule.

Refer to item 32.


1 Quantity

mismatch


400kV Class 4 20kA (1-phase)

gapless zinc oxide surge

arresters with pressure relief

complete with surge counters and

current leakage meter - 12 Nos

As per SLD

400kV Class 4 20kA (1-phase)

gapless zinc oxide surge

arresters with pressure relief

complete with surge counters and

current leakage meter - 9 Nos



price schedule..

Refer to item 20.


1 Quantity

mismatch





switches - 1 No

As per SLD




switches - 0 Nos



price schedule..

Refer to item 20.

26 of 33



Sr.





1 Quantity

mismatch


Post type (220/Ö3)kV/(110/Ö3)V





Class 3P/1 for instrument/BCU


phase (50VA for each winding) -

3 Nos

As per SLD






Class 3P/1 for instrument/BCU


phase (50VA for each winding) -

0 Nos



price schedule..

Refer to item 20.

27 of 33



Sr.





1 Quantity

mismatch


Post type combined current and

voltage transformer with 2 no. of

Class 0.2 CT cores per phase

with minimum rated output of 5VA

and with (220/Ö3)kV/(110/Ö3)V


winding inductive voltage

transformers of Class 0.2 with

minimum 10VA per phase for

high accuracy metering - 3 Nos

As per SLD

Post type combined current and

voltage transformer with 2 no. of

Class 0.2 CT cores per phase

with minimum rated output of 5VA

and with (220/Ö3)kV/(110/Ö3)V


winding inductive voltage

transformers of Class 0.2 with

minimum 10VA per phase for

high accuracy metering - 0 Nos



price schedule..

Refer to item 20.

106 Lamu Appendix D.2,

Schedule No.1,

Item No.5 , 5.2

KET-2014-D-

303 Lamu

400kV SLD

REV 2

Diameter 1:

Please confirm whether there is

an adequate space is available to

accommodate Tie CB Bay

Control unit in Diameter 1 Control

Panel

Yes.


Schedule No.1,

Item No.5 , 5.4

KET-2014-D-

303 Lamu

400kV SLD

REV 2

Diameter 2:



accommodate Reactor(SR2) CB

Bay Control unit in Diameter 2

Control Panel

Yes.

28 of 33



Sr.





Schedule No.1,

Item No.5 , 5.4

KET-2014-D-

303 Lamu

400kV SLD

REV 2

Diameter 3:



accommodate Reactor(SR1) CB

Bay Control unit in Diameter 3

Control Panel

Yes.

109 Lamu General Please confirm that necessary

space provisions is available in

the control room to accommodate

the protection and control

cubicles.

Yes.

110 Lamu Lot C_Tech

Spec_Section

V,Clause 11,

LV service

equipment,

11.2, Scope of

works

Lot

C_Appendix

C.2_Schedule

of Technical

Particulars_La

mu 400kV Ext,

I. LV services

equipment, 1.

110V DC

system-

substation

services

supply.

As per the price schedule the

110V DC & 48 V DC qty are

mentioned as zero , we presume

that existing DC system is

sufficient to cater the requirement

of new bay extension & no DC

system is included in the bidders

scope.

Kindly confirm our understanding.

Correct.

111 Hindi General Please provide the altitude of

Hindi substation.

Approximately 220m.

112 Hindi Price schedule

1 Item 7.1

"Main earthing system for the

complete substation:- Substation

underground earthing system

with rating of 31.5kA, 1 Sec for

220kV."

We presume main earth mat is

already existing and 220kV

equipment earth risers alone

considered in present scope.

Please confirm.

Change of scope. Earthing would be only required for the

extented portion and shall interface with existing gird.

29 of 33



Sr.




113 Hindi General Please confirm that necessary




cubicles.

Yes.

114 Hindi

Price schedule

1 Quantity

mismatch


220kV Post type current

transformer (1-phase) - 1 No

As per SLD

220kV Post type current

transformer (1-phase) - 3 Nos



schedules 1 and 4 accordingly.

Change of scope. Price schedule revised and will be

uploaded as addendum.


1 Quantity

mismatch



(phase‑to‑neutral) (1-Phase) ,

two winding inductive voltage

transformers Class 3P for

protections, and Class 0.5 for

instrument and bay computer with

rated output 150VA per phase

(50VA for each winding) for

busbar - 0 Nos

As per SLD


(phase‑to‑neutral) (1-Phase) ,

two winding inductive voltage

transformers Class 3P for

protections, and Class 0.5 for

instrument and bay computer with

rated output 150VA per phase

(50VA for each winding) for

busbar - 1 No



schedules 1 and 4 accordingly.

Qty = 0. Price schedule revised and will be uploaded as

addendum.

116 Hindi General We presume that existing main

trenches for the proposed

extension bays are already

available. Only sub trenches

have to be provided. Please

confirm.

Extension of Main Trenches is required for the extension

works.

117 Hindi General Extension of LVAC, LVDC boards

is not in our scope. Please

confirm.

Extension on LVAC and LVDC shall be part of the scope

and the bidder upon contract award shall undertake a

study to determine the capacity of the existing system and

upgrade as necessary.

30 of 33



Sr.




118 Hindi General No scope of works is envisaged

for the future equipments and

equipments supplied by others.

Please confirm.

Change of scope. The current scope includes interfacing

with existing equiment or plant supplied by others.

119 Hindi General We presume existing towers and

gantries are already present for

the extension of transformer and

reactor bays.

Change of scope. New gantry and towers shall be

supplied for the new extension bays. Revised price

schedule will be uploaded.


Item 2.15

Tubular busbar for isolator

connection to the busbar alone

shall be considered. Main busbar

tubes are not considered in

present scope. Please confirm.

Change of scope. Main busbars shall be extended.

Revised price schedule will be uploaded.

121 Hindi KET-2014-D-

302_Hindi

220kV Rev 1,

Existing busbar current rating is

1250A but the bay equipments

are rated for 2000A. Please

confirm the actual requirement.

Comply to requirements.


1 Item 2.12

As per price schedule

220kV busbar inductive voltage

transformer - 2 cores with 0.5 and

3P

As per SLD

220kV busbar inductive voltage

transformer - 2 cores with 3P/1.0

and 3P


requirement.

The information shown in the tender is correct i.e. IVT is

existing and no requirement for new unit.

123 Hindi Lot

C_Appendix

C.3_Schedule

of Technical

Particulars_Hin

di 220kV Ext,

page 24 of 206

Current rating of all the

equipments in the extension bay

is considered as 2000A as per

technical datasheet. Please

confirm.

Refe to item no 121

124 Hindi General Please confirm that necessary




cubicles.

Yes.

125 Lamu Lamu Price

schedule Sl. No

5.9

As per site visit, Lamu substation

is not yet constructed. Hence

please confirm the requirment of

Fault monitoring panel.

It is assumed that the Fault Monitoring System will be

supplied by others under a separate EPC contract.

Therefore for this tender the bidders shall include the

scope to extend and interface with the Fault Monitoring

System to include the new plant items as necessary.

126 Lamu Lamu Price

schedule Sl. No

12.5

Please confirm the requirement

of VT Fuse Box & if the same is

required, please furnish the

details.

Not clear what the bidder is seeking to clarify. However

the requirement is to provide a marshalling box with

isolatable fuse links.

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Sr.




127 Lamu Lamu Price

schedule Sl. No

5.11

Please note that the Price

schedule mentions 220kV

metering panel but 220kV

Combine CT/VT requirement is

not mentioned in price schedule.

Hence please confirm the CT/VT

connection details for this. The

usual practice followed by Kenya

is procurement of Combined

CT/VT.

Qty = 0. Price schedule revised and will be uploaded as

addendum.

128 Lamu Lamu Price

schedule Sl. No

5.5

Lot A is has 220kV line from

Lamu to Hindi substation but Lot

C Lamu price schedule doesn’t

mention 220kV Line protection

requirement. Hence please clarify

the requirement.

Change of scope. Revised price schedule and documents

will be uploaded.

129 Lamu Lamu Price

schedule Sl. No

11.1

Please furnish 90 MVA

transformer technical data sheet.

Technical schedule is provided under section J. The

transfomer shall be auto-transfomer. The tender drawing

show as 2 winding power transformer, this will be revised

and re-issued.

130 Lamu Lamu SLD As per site visit Lamu substation

is not yet constructed. Please

confirm the land develpment

scope of this substation.

This information shall be provided at a later stage.

131 SLD Please note that Hindi SLD has

220kV Bus VT,however same is

not mentioned in the price

schedule & not available at the

Site. Please confirm the

requirement.

Refer to item no. 122.

132 SLD As per site visit meeting , Ketraco

confirmed that the revised scope

includes 2 Nos 220kV line bay.

Please furnish revised SLD & the

revised Price schedule.

See item no. 128.

133 NE SLD Please note that the NE 400kV

SLD mentions Bus VT as 3 X

400/r3 but in the Price schedule

only 2nos are mentioned. Please

clarify the exact requirement

See item no. 61.

134 NE SLD Please note that in the SLD the

transformer quantity is 4nos & in

the price schedule 3nos are

mentioned. Please clarify the

exact requirement

See item no. 43.

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Sr.




135 Altitude As per specification NE

substation altitude is 1600

Meters. In GTP already BIL

values are corrected for 1600

mm altitude.Hence please clarify

whether the offered equipment's

shall be as per GTP.

Yes.

136 Cl. 4.3.1.1 Please clarify the contacts for

Isolator whether copper or

Aluminium

The technical specifications has made references to

relevant IEC standards, and therefore the bidders shall

refer to the standards and comply accordingly.

137 SC Type test Please note that we shall furnish

relevant Type test reports only for

the CB,CT,VT,LA,Disconnector &

Earth switch. Please confirm the

short circuit test requirement.

Please read the tender requirements and fullfill all the

required criteria.

138 Cl 14.7.2 Please furnish the data of the

existing Transformer for parallel

operation

This will be only provided upon contract award and design

review.

139 Cl.15.6.14 Please clarify the galvanising

thickness requirement

The technical specifications has made references to

relevant IEC/International standards, and therefore the

bidders shall refer to the standards and comply

accordingly.

140 Cl 15.2.4 Please clarify whether Tank

construction is conventional or

bolted type for shunt Reactor

For the purpose of the tender all bidders shall offer bolted

type.

141 Design and

Engineering

4.4.2

Please let us know within how

many days notice has to be

issued

Not clear what the bidder is seeking to clarify.

33 of 33