1. School of Engineering
Two-months Industrial Attachment
Programmed
With
SP POWERGRID LTD
2014 Internship Programmed 22 Dec 2014 to 27 Mar 2015
Student Name: Muhammad Suradi Bin Ithnin
Contact Number: 81213059
Internship: Customer Project East Section (CPE)
Supervisor: Mr. William
Officer: Raj
1
2. Project/ Assignment Details
Testing and commissioning of LV Board and OG Board
Assist in service connection jobs and major works projects
Support the inspection, installation, testing & commissioning of LVB and OGB
Recommend improvements to processes so as to ensure compliance with technical
specifications and engineering standards
2
3. Summary
Customer Projects East (CPE) section is obligated to handle customer projects at distribution level in
Eastern part of Singapore. CPE, led by Deputy Tony Yeo Cheng Hee has a total workforce of 90
people and is divided into zones consist of senior officers, junior officers, administration group, fitter
and miscellaneous group. Each zone will be taking charge of different areas in the Eastern Part of
Singapore.The key responsibility of the section is to implement and timely complete the distribution
projects to meet local growth and customer demand. Apart from that, CPE section also executes
disconnection & reconnection requests from SP Services for both Contestable Customers & Non-
contestable Customers. I was posted to CP-East under zone 3. Zone 3 covers the Eastern part of
Singapore.
3
4. Safety Pledge
Safety Pledge
Safety is our highest priority
Every life is precious
Every accident is avoidable
We uphold safe practices and strive for zero accident
Group Structure
4
Singapore Power
SINGAPORE OPERATION AUSTRALIA
OPERATION
SP POWERASSETS SP TRANING AND
CONSULTANCY COMPANY
SP AUSNET (51%)
POWERGAS SP TELLECOMMUNICATIONS SPI MANAGEMENT
SERVICES
SP POWERGIRD SINGAPORE DISTRICT
COOLING (60%)
JEMENA
SP SERVICES POWER AUTOMATION (51%) ZINFRA
5. Com Session
Safety Awareness
They will have a safety talked once a month. Before the talked, they
will have a safety pledge. The talked consists of safety pledge, safety
alert, accidents, safety awareness, safety advice (What are the do’s
and don’ts). Every worker will be issued a card containing the safety
pledge
5
6. Safety Awareness
During my internship I have notice that there are posters about safety
around the office. Example of posters like wearing proper attire for
Personal Protective Equipment (PPE) and handling live equipment.
6
8. LV Board
Two types of LV Board 6.6KV substation and 22KV substation
incoming
Used for Distribution of electricity supply at Low voltage
Located inside a substation
6.6kV substation LVB(Old) 22kV substation LVB
Distribution units
Transformer
9. Fuse Sizes for LV Service Cables
9
Cable Size Fuses Used
35mm² 2/C Cu 100A
35mm² 4/C Cu 100A
120mm² 4/C AI 400A if 200A back- up fuses are
installed at customer switchboard;
200A otherwise.
185mm² 4/C AI 400A
300mm² 4/C AI 400A
300mm² 4/C Cu 500A/ 630A
4 X 500mm² 1/C Cu 630A
7 X 500mm² 1/C Cu Large service units are used. Otherwise
solid links shall be used in placed of
fuses.
11. LV Board
Commissioning of Low Voltage Board
1. Ensure that the insulation floor mat is placed in front of LVB
2. Check the copper braid of the LV cables are tightened to the earth bar of LVB
11
12. LV Board
Commissioning of Low Voltage Board
3. Check all earthing points are tightened
4. Check the transformer neutral incoming link is tightened to the neutral bar of
LVB
12
Neutral Incoming
Link
13. LV Board
Commissioning of Low Voltage Board
5. Check that the bus-coupler and transformer
incoming links are in open position.
6. Ensure that the transformer incoming links
remain open as long as the transformer is not
energised
13
14. LV Board
Commissioning of Low Voltage Board
7. Ensure all LV cables terminated at LVB are properly tightened
8. Ensure all outgoing LV cable terminated are installed with earth fault indictor;
14
15. LV Board
Commissioning of Low Voltage Board
9. Ensure that no fuses/ links are inserted in each distribution units
10. Ensure that the rating of the fuses to be used for the respective cables is in line
with that as shown in SPPG-ND-OI-DC (Proj-TS)-02; AND
15
Fuse Blow
1) Cable fault
1) Overloading
1) Ageing Fuse
16. LV Board
Commissioning of Low Voltage Board
90s old LV Board fuses used for 6.6kV substation
11. Check substation auxiliary supply cables are terminated properly
16
17. 6.6kV Substation LV Board(Old)
17
Fuse to let the supply
flow.
Labeling is to
indicate which unit
is being used or spare
SPPA LVB (Special Procedures)
18. 6.6kV Substation LV Board(Old)
18
All earthing cable will be terminated at the
earthing point.
21. LV Board
Upon commissioning the LVB, Project Officer shall
1. Check the voltmeter and the selector switch are functioning properly
2. Check the voltage at LVB is 230V±6% phase to neutral and 400V ±6%
phase to phase
21
Voltmeter
22. LV Board
3. Ensure that the phase sequence of LV cable is correct
4. Ensure LVB doors are closed and locked properly before leaving site
23. LV Board
Upon commissioning the LVB, Project Officer shall
5. Turn on the auxiliary supply to the substation
23
26. Glossary
26
In the Event of Emergency
Term Contact number Example of Event
ESC 6778 8888 1. Circuit Breaker trips
2. Black out
3. Public complaint of no
supply
4. Swgrg panel’s Alarm
indicator “ON”
5. Diversion 3-4hours
27. OG Board
Before entering a substation. The Project Official
required to get a key for the OGB.
27
M(Master)2(22kV substation)N(North)=M2N
M(Master)6(6.6kV substation)N(North)=M6N
29. OG Board
29
Cable size: 35mm²
2 nos of service cable
in one single unit
Fuse: 100/200A
Cable size: 300mm²
3 Phase
30. OGB Earthing
Earthing located at cable armoring.
The armoring is connected to Substation Low Voltage
Board
It is then connected to the Earth point located at the
Basement of Substation.
Trench
Main Earth
31. OG Board
Installation of Overground Distribution Board
1. The Project Officer shall:
2. Indicate clearly to the Contractor the exact orientation and position of OGB to be installed;
3. Ensure that adequate space is available around the OGB for jointing and network operation and
maintenance; and
4. Ensure that the OGB installation checklist is properly filled and signed before taking over the OGB
from the contractor
31
32. OG Board
Commissioning the OGB, Project Officer shall
1. Voltage check using tong tester
230V ± 6% Phase to Neutral
400V ± 6% Phase to Phase
32
Phase to Neutral
(216.2V-243.8)
Phase to Phase
(376V-424V)
241V
418V
33. OG Board
Commissioning the OGB, Project Officer shall
2. Ensure that the phase sequence of LV cable is correct; and
3. Ensure OGB doors are closed and locked properly before leaving
33
38. Recommend Improvement
Widening the space of the Low Voltage Board
termination point
Using a insulated Busbar for safety
Termination pointBusbar
Before i talk about LV and OG Box, i will talk about Safety. Safety is the company priority.
Cu stand for Customer.
What is a floor mat used for? From safety. It keep the insulation
The busbar at the Neutral will be connected to the main earth located at baseman substation.
Earth fault indictor is a device which are tripped when there is a short circuit.
Auxiliary supply are distributed to DB, lighting etc
Incoming supply comes from the transformer
All earthing cable will be terminated at the earthing point. It is to ensure powered equipment, exposed metal parts are connected to ground to prevent user contact with dangerous voltage if electrical insulation fail.
Auxiliary supply is used to give supply to the substation. Example lighting, Switchboard etc.
Auxiliary supply is used to give supply to the substation. Example lighting, Switchboard etc.
The auxiliary is used to give out supply to the substation. Example lighting, DB etc
What’s the different between them? The physical look is different one is bigger than the other but both function the same. The centre has a locked. Why it has a locked? Well because it located is at a area where there has less people. Example like highway.
Because of the small cable size, the fuse needed to used is 100A. Red indicate Line and Black to indicate Neutral.
Number 3 is the incoming. It is using 300mm² 3 phase. It is connected to a substation. The whole busbar are linked. It is to give out the supply.
Number 4 is connected to another OG Board. It is using 300mm² 3 phase.
The project official need to get a key for the substation he/she is heading. Before heading to the OG Board, the Project Official has to get a key. This key is used to unlock the OG Board. The box that contains all those keys has an alarm. The Project Official will be given 24hours before returning the key back.
Each OGB unit is connected to a customer or OGB . The housing address can be found at the labelled section. Sitting of OG board should be at conspicuous location and not causing obstruction to pedestrians or vehicles. As near as practicable to the customer’s supply intake point/switchboard. Red indicates L1, Yellow indicates L2 and Blue indicates L3.For the cable size of 35mm² /3 phase uses 100A. Neutral busbar is connected to the substation transformer (Star). Neutral and earth are common. Each has User
Because of the small cable size, the fuse needed to used is 100A. Red indicate Line and Black to indicate Neutral.
Number 3 is the incoming. It is using 300mm² 3 phase. It is connected to a substation. The whole busbar are linked. It is to give out the supply.
Number 4 is connected to another OG Board. It is using 300mm² 3 phase.
What is upper jaw? Upper jaw is connecting to the busbar. Each busbar has a supply. Red, yellow, Blue and Neutral/ Earth. All the busbar are connected to the main incoming of the OG Board. The cable that is the biggest is the incoming. Let say there are 2 300mm² cable. How to know which is which. By using a Clamp on tester.The one that has the higher voltage is where the supply is coming from. The other could be connecting to another OG Board. The Lower jaw is the outgoing. Going out to customers.
Using a lamp tester, the project officer have to check the phase sequence whether it is correct or not. Busbar and cable end.
Before reaching the excavation work, there will be 3 signs. First sign is Caution to warn people that there is a excavation work. Works Ahead is the second sign. Third sign is to indicate which road is being used for excavation. The bottom left shows a expected completion when the excavation is done. It is to notify the resident.
Straight jointing is for diversion. Intermediate is for length.
This is where they keep all the completed project. Located at the ground floor.
