This document discusses the scope and compliance of procurement and contracts for public sector projects. It covers the scope of procurement, the role of procurement, and compliance with procurement contracts. It focuses on ensuring the needs of the public sector are met and contracts are established according to documented parameters. Proper procurement helps guarantee the delivered product or service meets the intended needs.

1. scope and compliance of
procurement & contracts
in public sector projects

2. Presented :
Presented To: Board
Employer:
Designation: (Electrical)
Senior Engineer
2

3. scope in public sector projects
Scope of
Procurement
Role of
Procurement
Compliance
of
Procurement
Contracts in
Public Sector
in Projects
3
Prepared By: Engr. Muhammad Arshad Jawad
(MSEE01121007)

4. Scope of Procurement in
public Sector
The scope of work in a procurement is a
component of a solicitation and describes the
Department's needs and desired outcomes for
the procurement.
4
Prepared By: Engr. Muhammad Arshad Jawad
(MSEE01121007)

5. Role of Procurement
5
Prepared By: Engr. Muhammad Arshad Jawad
(MSEE01121007)
The scope of work in a procurement is a
component of a solicitation and describes the
Department's needs and desired outcomes for
the procurement.
The scope of work helps to ensure that the
product or service meets the documented needs
and establishes the parameters of what could
be included in the contract.

6. In Pakistan, usually transmission is done on 500kV,
220kV & 132kV voltage levels.
As we know the majority of faults occurs on
overhead transmission lines and they are almost
50% of the whole network.
The most likely occurred fault is Line to Ground
(L-G) fault and its occurrence is almost 85%.
The type of faults that may occurs on transmission
lines are shown in the Fig. 2.
6
Overhead Transmission Line
Faults
Prepared By: Engr. Muhammad Arshad Jawad
(MSEE01121007)

7. i. Fault A: Line to Ground (L-G)…………………85%
ii. Fault B: Line to Line (L-L)…………………………8%
iii. Fault C: Double Line to Ground (L-L-G)…………..5%
iv. Fault D: Three Phase (L-L-L)………………………2%
v. Fault E: Three Phase to Ground (L-L-L-G)
7
Overhead Transmission Line
Faults
Fig. 2
Prepared By: Engr. Muhammad Arshad Jawad
(MSEE01121007)

8. 8
The following mechanism are used to protect the
overhead transmission line from any kind of fault.
EHS Shield Wire/OPGW
Tower Grounding Arrangement
Conductor Sagging
Insulators & Arcing Horns
SBVD/SD
Line Bay Arrangement
Overhead Transmission Line
Protection
Prepared By: Engr. Muhammad Arshad Jawad
(MSEE01121007)

9. 9
Extra High Strength (EHS) Shield Wire/Optical
Fiber Grounding Wire (OPGW):
The EHS Shield wire/OPGW are connected to the
peak of any tower and the tower is itself grounded
with the help of grounding arrangement.
Normally, single EHS Shield Wire/OPGW is used
on 132kV and 220kV, where as one EHS SW &
one OPGW or both OPGW are used on 500kV
transmission line towers.
Overhead Transmission Line
Protection
Prepared By: Engr. Muhammad Arshad Jawad
(MSEE01121007)

10. 10
Tower Grounding Arrangement:
The tower grounding is done when the foundation
is laid down.
This arrangement consists on the following
components.
Grounding Rod (16mm/3m)
Earth Wire (7mm 10 No./2.5m)
Cable to Rod Connector & Flat to Cable
Connector
Overhead Transmission Line
Protection
Prepared By: Engr. Muhammad Arshad Jawad
(MSEE01121007)

11. 11
Conductor Sagging:
The proper conductor sag is done to maintain the required
clearance level from the ground level and from the other
lines as well.
The minimum clearance level is 8.5m for 220kV
transmission lines & almost 12m in case of 500kV
transmission lines.
The clearance level may change with the change of
ground features as well as the crossing parameters of the
transmission line.
The required clearance level is marked and calculated on
the profile with the help of template & Sag Tables
respectively.
Overhead Transmission Line
Protection
Prepared By: Engr. Muhammad Arshad Jawad
(MSEE01121007)

12. 12
Overhead Transmission Line
Protection
Insulators & Arcing Horns:
 The insulators and arcing horns are attached with
the cross arm of the tower and the conductor(s).
 Single or Double arcing horns are used with the
insulators arrangement. It depends on the design
and working condition of the transmission line.
 The guard rings are also used with insulators for
this purpose.
Prepared By: Engr. Muhammad Arshad Jawad
(MSEE01121007)

13. 13
Stock Bridge Vibration Dampers (SBVD)/Spacer
Dampers (SD):
The SBVD & SD are used to protect the
conductors from striking with itself and also
controls the vibration of the conductors.
The spacer dampers are normally used within the
bundle conductors for maintaining the proper
clearance distance between the conductors.
Overhead Transmission Line
Protection
Prepared By: Engr. Muhammad Arshad Jawad
(MSEE01121007)

14. 14
OHTL Connectivity with
Substation
Line Bay Arrangement:
The line bay arrangement is required when any
transmission line is connected or terminated in the
substation.
This line bay is connected with the bus bar bay
with the proper protection arrangement and
according to the designed scheme.
The line bay itself has a protection
scheme/arrangement to overcome the fault and to
protect from any kind of damage.
Prepared By: Engr. Muhammad Arshad Jawad
(MSEE01121007)

15. 15
OHTL Connectivity with
Substation
The line bay arrangement has the following
equipments:
Surge Arrestors
CVT
Line Traps
Circuit Breakers
Disconnector /Disconnectors with Earthing Switch
Shunt Reactors
Prepared By: Engr. Muhammad Arshad Jawad
(MSEE01121007)