6/6/10 to 24/6/10 Department of Project

7.1 Scoop of Works
-7.11 Project Planning
Economics and feasibility studies, preminary engineering design, cost estimates and economic evaluation of any alternatives. The projects are done without waste the money .The consultant also give advices on site selection, construction method and equipments
-7.12 Project Management
Planning, coordination and control of all activities of any project in terms of cost estimation time and function to ensure that the clients the objectives are met.
-7.13 Advisory Activities
Design reviews and independent design checks certification procedures and expert advise in all areas of the firm expertise.
-7.14 Engineering Design
Conceptual design, detailed design, drawing and specification, cost estimates and project scheduling.
-7.15 Tender Arrangement
Preparation of tender documents, registrations of tenders, invitation to tender and orders to nominate sub-conductor. Tender evaluation, interview and recommendations.Prepations of contracts documents.
-7.16 Contract Administration
Financial control, payment certificated and settlement of accounts.
-7.17Supervision of Construction
Quality control and inspection of fabrication and construction. Provision resident engineer, supervisor and inspectors.
7.2 TESTING AND COMMISSIONING
7.21 Primary Injection Test
The purpose of PI test is:
a) to ensure that the system wiring connection is in order
b) to check CT’s ratio and polarities
c) to confirm that the CT’s characteristic are matched with each others
7.211 Test Procedures
The testing procedures are as follows:
a) Set up the PI set and connect the ammeters as shown in the diagram below for various protection scheme
b) Ensure continuity of the secondary circuit by switching the ammeters to ohm range
c) Ensure that the primary circuit is in order and inject primary current equal to half of the rated primary current of the CTs.Take ammeters readings
d) Bring up the current to the rated primary currents of the CT’s and take reading again
e) For new equipment is in order, the leakage current should be lower than the max acceptable value
7.22 Secondary Injection Test
The prime purpose of secondary Injection Test (S.I) test is to ensure the entire relay is functioning as excepted. It is very important to test the protective relays for the correct operation of the circuit breaker under normal and fault conditions. This is the responsibility of there testing officer to make appropriate interpretation on test results and initiate the necessary action for remedy action for remedy if required.
Precaution: Do not open-circuit the secondary of a CT while there is a produced in its secondary which may be dangerous to persons and may also damage the insulation of the secondary wiring.
7.23 Test for Over-Current or Earth-Fault Relay
The purpose of the test is to measure that the relays are in a good condition and can play a role as a back up protection unit.
Procedure:
1) We need to short circuit of the CT ,and take up the CT wiring on the relay
2) Set up and injection device and inject the current to the relay check the crippling ampere
3) Continue inject current according to the data shhet.1.3x,2x,3x and record down all data time of tripping and current injection and relevant information
4) Inject at the 2 or 3x rated current and set on the shunt trip coil of the Circuit Breaker
*The circuit diagram of o/c & e/f attached appendix
*Attached with a sheet of the over-current and earth fault relay at appendix
7.24 High Tension Test
7.241 A.C Pressure Test
Before the power equipments are put in services ,they are subjected to high tension test to ensure that the insulation level of the equipment is high enough to withstand over-voltage under different conditions,eg switching transient ,system fault ,lighting surge ,etc the A.C pressure test is applicable for switchgear ,bus-bar ,current transformer ,potential transformer and power transformer.
7.242 D.C Pressure Test
D.C pressure test is applicable to power cable only .We do not apply A.C pressure test for cable because the capacitance of the cable is very high.
7.25 Contact Resistance Test
To ensure the resistance of the circuit breaker main contact still within the range according to international standard
7.26 Transformer Dielectric Oil Test
The purpose of Dielectric Oil Test is to ensure that:
1) Determining the dielectric strength of insulating oils in transformer ,switchgear ,and other electrical apparatus
2) Oil degradation takes place due to oxidation ,acids ,sludge ,gas , and water absorption
7.27 Cable Continuity
The purpose of the test:
1) To make sure the control cable laid by the contractor is according to the specification and design
2) To confirm no damage on the cable and ferruling of multi –cores are as per cable core schedule
7.28 Insulation Test for Cable
The purpose of the test:
1) Make sure the other cable is isolated from earth
2) Make sure no direct fault to earth of the cable cores
7.29 Current Transformer
Current Transformer divides into two types namely: metering and protection
For metering is using Class 0.1 to Class 5.Smaller number of class, the higher the accuracy is
For protection is using 5P10, 10P10, 10P5 and others
Example: 5P10; 5=percentage of error and 10=times of saturation point
Some of the test result attached at appendix

7.7 SINGLE POINT BONDING
-For short cable, eg: Transformer tail and from panel PMU to panel SSU at the same premise/substation

7.8 Difference between Flat and Trefoil Cable



-Higher ampacity(for non-touching flat) -Lower ampacity
--Higher unbalanced voltage (limit of unbalanced<2%) -There is no unbalanced voltage
-Needed transpose core at every joint which is made from crossbond -Need not transpose core. Only crossbond
-More easier and simply,

7.9 Failure of Underground Cable
-Based on research, main reason around 54% shown that failure of underground cable caused by excavation by third party.
-This failure included excavation activities at the side road
-Period of failure:
-Immediately-once excavate will spoil
-Spoil after a period of time-Cable be distressed or flat caused by excavation
-7.91 Increment Degree Of Depth Due To Plantation Of Cable
-Avoid cable from top bucket junkets which is used by third person during excavation. Degree of depth had to increased from 2.5 feet to 3.5 feet
-Below figure1 shown the most accurate and safe location of cable after testing the depth of excavation of cable
Figure1

Latest method of plantation cable with explanation depth