AF Technical

SAFETY INSPECTION ON 11-KV SYSTEM (Part 2)

2008-11-15T00:59:00.000-08:00

Regulations 66 of Peraturan Elektrik 1994 stipulates that Safety Inspection on electrical installation which receives electricity supply rated more than 100A from Supply Authority (other than domestic installation) need to be inspected by competent person at least once a month (those with stand-by generators). Thus, every electrical installation should be kept in a tip-top condition to ensure security of supply and safety of personnel operating the installation. An air base is one of the critical installations which should be well-maintained as it is very critical to protecting country's sovereignty.
Recently I visited one of the 11-kV installations maintained by JKR. The visit was arranged to guide or enhance the capability of JKR Electrical Personnel in carrying out Safety Inspection works on electrical installations maintained especially the high voltage system.

As the exercise took only about four hours, we had only minimum time to inspect and conclude on the findings. Append below are some photographs taken at site during the inspection for reference. The remarks are purely personal and if anyone needs any further information, please contact the author.

Kota Bharu..

SAFETY INSPECTION ON 11-KV SYSTEM (PART 1)

2008-10-24T17:06:00.000-07:00

Safety Inspection on electrical installation which receives electricity supply from Tenaga Nasional Berhad (TNB) or other supply authorities in Malaysia through a circuit breaker more than 100A (other than domestic installation) is mandatory. This is clearly stated in Clause 66 of Malaysian Electricity Regulations 1994 which is to be read together with Electricity Supply Act of Malaysia 1990 (Act 447).
The Competent Person, Duties of Inspectors and Frequency of Inspection on the installation are stipulated in Clauses 67, 68, 69 and 70.
Recently, I had an opportunity to carry out safety inspection on an 11-kV installation together with Engineers, Technicians and Chargeman from JKR Elektrik Selangor.
Append below are some of the findings which I like to share with others on the observation and actions to be taken to overcome the shortcomings.

Photo 1A
The VCB truck has been removed for maintenance. The barrier provided for is inadequate to prevent access by unauthorised person. Accident could happen by just lifting the shutters (yellow & red) and exposed oneself to the live 11-kV busbar/cables behind the shutter. No warning notice was erected.
Solution :
The bus bar and circuit/cable shutters (photo 1B) should be locked. VCB opening should be blocked by using a bigger cover with DANGER and WARNING signages posted on it e.g. BAHAYA, JANGAN HAMPIRI PANEL INI..

Photo 1C
The RC slabs of cable trench cover are broken and sharp concrete left-over are risk to personnel especially at night.
Solution :

The trench could be filled up with sand and rendered with a thin layer of plaster at the same floor level. This will enable future access to the trench should a new circuit to be added.

Photo 1D
The First Aid Chart displaying The Holgger-Nelson's treatment method has been banned by the International Red Cross Society.
Solution :
A new first aid chart describing Cardiac Pulmonary Resuscitation (CPR) shall be installed to replace the existing one.

Observation :

2A & 2B - missing screws to the 11-kV panels need to be replaced immediately and URGENTLY. This is because, the panel has been designed equipped with the necessary screws to prevent the panel from being thrown out during untoward accident.
2C & 2D - DC supply system is very critical to the safe operation of high voltage equipment. DC is used to power up tripping coil of circuit breaker (open the circuit breaker during fault or when required), power supply to protection relays, etc. As such, DC supply system must always be made available to the panels and it must be maintained properly. Every care must be takento keep the DC system in tip-top conditions by following maintenance schedule recommended by the manufacturer.

Observation :

Switchgear labelling may seems trivial to some but actually it could cause unnecessary lost of lives if it is taken for granted.
Switchgear labelling must at all times be correct and updated immediately if necessary because the label on the panel is always referred to during any activity involving the panel (data-taking, switching, maintenance, replacement, etc). Wrong labelling on the panel could cause wrong switching to me made which may result in accident or lost of power supply. As such, the labelling on the panels must always be determined, updated, corrected and concise to ensure all activities carried on on the panel is always right and accident-free.

Observation :

4A & 4B - show the readings displayed by the respective ammeters and voltmeters of the incoming supplies (no. 1 and 2) from Tenaga Nasional Berhad. The ammeters show that the two incoming feeders from TNB are carrying 40A and 160A respectively.
From those readings, the Maintenance Engineer should always try to balance-up the two feeders as close as possible. This will ensure that both feeders are almost equally loaded and should one of the feeders experiences a power disruption, only about 50% of the installation is effected. If the shown readings are left unchanged and should the higher-loaded feeder experiences a fauly and trip, 80% of the installation load will be disrupted.

Observation :
Gauge 5A shows that there is still gas in the tank while gauge 5B shows that the gas has totally discharged from its tank. Maintenance personnel shouls always check that the gas content of the appropriate fire fighting system must always be made available to face any unwanted accidental fire so safe guard the installation.
Temperature gauge of 5C shows the oil temperature recorded of an oil transformer. This temperature gauge also acted as an Alarm and Trip protective device that will permit or stop the flow of current into the transformer depending on the condition of the transformer temperature. So, every gauge function must be fully understood by the maintenance personnel so that a right and prompt decision could be made to ensure the availability of power supply to the installation is always safely maintained.

T & C OF HT EQUIPMENT AT USIM NEW LIBRARY SUB-STATION

2008-09-20T09:53:00.000-07:00

Views of USIM new Library Building - almost ready to
be commissioned and used (19-Sep-2008)

Universiti Sains Islam Malaysia (USIM) new library building construction started about two (2) years ago and now it is in the final phase of construction. Located on a hill behind Computer Science Faculty, the building will be another landmark of USIM campus.

Incoming 11-kV cables to feed electricity supply
to the sub-station no. 9 (Library)

The building electricity power supply is fed through Pencawang Elektrik No. 9 (PE09) which houses circuit breakers, step-down Cast Resin transformers and Low Voltage Switch Board. The power supply is also back up by a stand-by generator set. As the building M&E equimpent and services are almost ready to be tested and commissioned, its electrical infrastructure contractor is also busy completing the installation. The pre-testing and commissioning of sub-station equipment are being carried out by the Electrical Service Contractor engaged by the electrical contractor who was awarded the job via an open tender system.

All the 11-kV system for the building which comprises of 11-kV power cables, vacuum circuit breakers (VCB), 2 x 750 KVA 11/0.433-kV transformers must be fully tested before putting them into service. The operation of the VCBs can be carried out via Remote Control Panel (RCP) and the transformers are protected by Digital Temperature Relays. The VCBs are also equipped with Schneider SEPAM 1000+ OC/EF relays.

11-kV Vacuum Circuit Breaker at sub-station no. 9 (Library)

750KVA 11/0.433-kV Cast Resin Transformer

The following Basic Site Tests are being carried out on the high voltage equipment BEFORE they are put into service :

A. 11-kV Underground Cable - Insulation, phasing & Pressure Test (AC - VLF);
B. VCB - Insulation(1), Vacuum Check, Pressure Test, Insulation Test(2). Check on limit switches, tripping coil, heaters, meters, indicators, etc.
C. Transformer - Insulation and Ratio Test, Temperature Relay tests (Alarm & Trip)
D. RCP - Operation and status of VCB and Earth Switch.
E. Earthing/Grounding Test - ensure low Earth Impedance on Main Earth Bar and Transformer Star Point earth;
F. Protection Relays - CT Tests and SCIT Tripping Test;
G. Safety Clearances of all HT cables, transformer housing, terminations, etc.
H. DC Supply System - battery voltage, charger and capacity.
I. Others : Rubber mat, as-built drawing, Danger sign, No-Entry sign, CPR Chart, No Smoking sign, vermin-proof netting, cable trenches, trrench covers.

Once the Service Engineer has verified that all equipment tested are safe to be energised (via Form H), the HT equipment (all initially in OFF state) will be energised to receive electricity supply in the following Switching Sequence :

1. Switch ON supply from existing sub-station to the Incomer VCB (OFF position);
2. Verify 11-kV Voltage
3. Switch ON Incomer VCB (VCB 9B);
4. Verify voltage on busbar
5. Switch ON VCB 9C
6. Verify outgoing cable is energised;
7. Switch ON supply to Transformer No. 1 (VCB 9A)
8. Verify Voltage and Phase Rotation at LV Board;
9. Switch ON supply to Transformer No. 2 (VCB 9D)
10.Verify Voltage and Phase Rotation at LV Board.
11. Subsequent switching on LV Board will then be carried out.

1 - Potential Transformer; 2 - VCB Panel Heater
3 - PT HT Fuse; 4 - Relay and Panel Accessories

11/0.433-kV Cast Resin Transformer & Temperature Relay

BBNilai..

KOMTAR JB - SEPTEMBER 2008 STATUS

2008-09-15T09:39:00.000-07:00

The KOMTAR Upgrading Project Team ...

Advertisement on New Faces of KOMTAR JB as pasted on the Bill Board Hoardings :

The building contractor had entered the project site in November, 2007 and the project is supposed to be completed by May, 2009. Fortunately or unfortunately, at the midst of the construction, it seems that the owner has discovered that for the project to be certainly viable, bearing in mind that an investment of about RM 50 million has been allocated for the upgrading project, the podium section will be increased or catered for 6-storey building, instead of just 3-storey originally.

With the new decision, the demolishing area on site has been increased and consultants/designers of the podium block has been requested to re-check and ammend/update/redesign the building to include the next three stories which are mainly car parks. With the decision also, the floor-to-ceiling height of the first floor has been increased to cater for the M&E services and to create ceiling space especially for the big supermarkets.

So, the final status whether the new portions of the block will be constructed concurrently with the exisiting Phase A project will only be known on the 18-September, 2008 where the Johor Corporation Board Meeting will be held.

Photographs below show the status of construction today (15-09-2008) ...

Johor Bahru .. 15_09_2008

NEW UTHM LIBRARY TAKING SHAPE

2008-08-31T02:44:00.000-07:00

The Main Library Building from Utility Block (M&E Services)

Universiti Teknologi Tun Hussein Onn Malaysia (UTHM), Batu Pahat is constructing a new 6-storey cylindrical block to house its Main Library. The block will also house six Lecture Theatres (to accommodate a total of 1,000 students), Vice-Chancellor Office and other administration offices.
The building is being constructed by Pembinaan Hamid-Ecovest Construction JV Sdn. Bhd., an established Design-and-Build Contractor in the country. The consultants involved inthe project are :
1. Juhari Hashim Architect (Architecture)
2. SAFF Consultants (Mechanical & Electrical Engineers)
3. Kristal Padu Sdn. Bhd. (Quantity Surveyor)
4. Civil & Structure Engineers
5. AV Consultant
6. ICT Consultant
7. Landscape Consultant

Recently on the 20-August-2008 (20-08-2008), I managed to visit and inspected the site. The new building is taking shape and the construction has reached the second (2nd) floor.
It is hoped that the building will be completed on-time to provide a modern and up-to-date library facilities to the students and surrounding community.

AFK_Skudai

UPGRADING 11-KV SUB-STATIONS AT UTHM

2008-08-29T09:42:00.000-07:00

Unloading of 200mm x 200mm RC Pile from Lorry at SSU 1

The upgrading works on 11-kV system at UTHM has been awarded to a cloass 1 Electrical Contractor at a cost of about RM 6.7 million. The works comprises of building a new Switching Station No. 1, constructing two new 11/0.433-kV sub-station buildings, upgrading the existing TNB sub-stations and supplying the 11-kV and 415-V related electrical equipment required in the SSU1 and sub-station buildings.

Unloading of 150mm x 150mm RC Pile from Lorry at PE 02

Today (29-08-2008), two lorry loads of RC piles have been delivered to site by the contractor. The setting out of SSU 1 and PE 02 had been confirmed by UTHM and the piling work will start very very soon.

With the initial commitment shown by the contractor, we hope the project could be completed ahead of time so that the activities and programs arranged by the UTHM could be carried out smoothly without any problem or shortcoming.

BPahat/Skudai

NEW CHILLERS TO BOOST USIM A/C PLANT ROOM

2008-08-25T08:59:00.000-07:00

USIM Central Utility Block No. 1 which housed 2 x 400 TR was commissioned in 2006 to supply chilled water to the Administration Block and Pusat Teknologi Maklumat.

Recently, the plant has been upgraded with the additional 3 x 400 TR Chillers which were successfully commissioned. This has increased the plant capacity to 2000 TR which will be used to feed chilled water to the new faculties under construction i.e Fakulti Quran & Sunnah (FQS), Fakulti Ekonomi dan Muamalat (FEM), USIM Main Library and Students Affairs buildings.

Due to very high starting currents of chillers (and compressors), Variable Frequency Starters or Soft Starters (SS) are used in the Chiller Control Panel. The starters (Danfoss) are used to limit the starting currents at a known period and are co-ordinated with the protection relays to prevent tripping of breakers during starting. The relay characteristic curves need to be changed from the normal IDMT Standard Inverse to the IDMT Long Time Inverse at the Circuit Breakers before the SS.

The plant is also equipped with the latest Building Automation System (BAS) whereby the chillers could be remotely monitored and controlled.

BBNilai

NEW IPD SELAMA COMPLEX

2008-08-20T09:15:00.000-07:00

Recently, work has started to constrcuct a brand new and modern office complex at Ibu Pejabat Daerah Selama, Perak.
The works awarded to a contractor from Ipoh consists of consruction of new buildings over the existing ones. This entails the shifting of equipment to a temporary buildings for operational continuity.

Yesterday, the demolishing of existing quarters block was undrway and the hob'c risk is high.

COMMISSIONING OF 11-KV SUPPLY

2008-08-05T09:48:00.000-07:00

Universiti Sains Islam Malaysia (USIM) formerly known as Kolej Universiti Islam Malaysia (KUIM) main campus is located at Bandar Baru Nilai, Nilai, Negeri Sembilan.
The campus initially received its 11-kV supply from Tenaga Nasional Berhad (TNB) in 2005 via Stesen Suis Utama (SSU) No. 2, located just about 100 meters from USIM Main Entrance. This is because TNB was not ready to deliver its supply via its 132/33-kV Main Intake located to the North-Eastern tip of USIM Campus.

However, as the new buildings are being added to the campus, the initial supply of about 3 MW is expected to be exceeded by the new faculties buildings demand. As such, on the 11th. November, 2007 TNB has commissioned its two new 11-kV supply to USIM Main Intake Sub-station. TNB supply is fed via two 11-kV Overhead Lines circuits.

Thus, on the 11th November, 2007, 11-kV supply from TNB was safely transferred from SSU 2 to USIM Main Intake Sub-station. Intricate switching procedures were planned and carried out successfully without any accident. Live-phasing Test on 11-kV Test supply from two sets of TNB Incoming Feeders was carried out using Live-Phasing Sticks. The test was carried out by Syed Abdul Hadi (SAFF Testing Engineer) and me.

Alhamdulillah, at last a more stabilised and sizeable electricity supply system has been established and commisioned to USIM to ensure all its activities are not interrupted.

Bandar Baru Nilai

KOMTAR JB .. DI MANA WAJAH BARU MU ...?

2008-08-05T03:23:00.000-07:00

The project sign board and demolishing works of podium floors

Kompleks Tun Abdul Razak (KOMTAR) is the first high-rise building being constructd at Johor Bahru. It was constructed in 1970. Being the first high rise building constructed about 40 years ago, the building does not has all the modern Building Automation System (BAS) or BMS facilities to control and monitor its amenities to the users. Nevertheless, it has served its occupants well without any unto wards accident happened.

Project Team in a deep discussion while site work continues ..

The planning for KOMTAR Podium Commercial Complex at Jalan Wong Ah Fook/Jalan Tun Razak, Johor Bahru has started way back in 1995. It was put off several times due to several unforseen circumstances and reasons. At last, in January this year (2008) the upgrading works was awarded to a building contractor; Taqi Holdings Sdn. Bhd. The RM50++ million works is to be completed by September 2009 which will change the image of 1970s KOMTAR to a new modern and vibrant Shopping Complex in the city of Johor Bahru.

Clearing work at car park area for new lift core & loading bay ..

With its new facelift and new means of internal transportation system (travelator, escalator, bubble lift, goods lift, passenger lifts), bigger and wider atrium, ample parking space, pre-paid metering, new air-conditioning system, performance-based fire fighting system, wireless internet access and other modern amenities available at modern shopping and commercial complexes will bring up KOMTAR to be at par with other similar premises.

Main Concourse of KOMTAR and view of podium from Jln Tun Razak

So, hopefully, a long wait by the consultants, contrarctors, the users and the public will be paid off once the new KOMTAR is open next year.

Some of familiar faces from project team members.
View of temporary Kebayan Food Courts

To those in the Project Management Team, be steadfast in carrying out the tasks and try to give your level best to accomplish the mission ... May all our sincere effort to make the project a success be rewarded by Allah SWT...Ameen...

JBahru.

PROJECT SITE VISIT - SMKPP MUAR

2008-08-04T08:31:00.000-07:00

The site for Sek. Men. Keb. Persisiran Perdana (SMKPPP) is located at Tanjung Agas, Muar, Johor. The construction of this secondary project was awarded to the contractor sometime in December, 2006 and expected to be completed by September, 2008. However, based on current progress of th project, it is envisaged that the project could not be completed on time.

The electrical contractor was appointed around April, 2008 this year and had since been working on the project. Today's inspection, visit and meeting on the project had given me an opportunity to meet with the contractors and site staff. Informal discussion was held at the Canteen while watching the contractor working.

As for TNB sub-station building, it needs to be handed over to TNB in a good condition and as per TNB requirement. The photographs below show the existing sub-station building and cable trenches which need to be completed and tidy-up.

Among items that the cointractor needs to prepare are :
1. Corrugated HDPE TNB cable pipes shall be made up of solid HDPE 150mm diameter;
2. To repair/make good cable trench inside Transformer Room;
3. Vermin-proof netting size shall be SWG23 Mesh 10;
4. To repair leaks at ceiling slab inside Low Voltage Room;
5. To replace DANGER and NO ENTRY notices at sub-station doors with standard notices;
6. To clean up cable trenches;
7. To pump out water from cable trench;
8. To paint TNB logo on sub-station building;

Factory Acceptance Test (FAT)

2008-07-26T07:27:00.000-07:00

Factory Acceptance Test (FAT) is one of the important processes in Mechanical and Electrical (M&E) System installation during the construction phase of a project. In every M&E works, FAT is carried out after the approval of Shop Drawings by the project M&E Consultant, signifying that the manufacturing process of the switchboard or equipment could be carried out based on the Approved Shop Drawings.
FAT must be witnessed by the Consultant (designer) and the Superintending Officer and often accompanied by the Client to ensure that the products are manufactured in accordance to the tender specification. The various tests which have been specified in the Tender Specifications are to be carried out and witnessed by theproject team. The tested values obtained during the FAT must be as specified by the contractor in the tender submission (with standard tolerances allowed for by IEC standards).
Last Tuesday, I had a chance to attend a FAT on Chiller Switchboard of one of our projects. The FAT was carried out at the Energy Commission-approved Switchboard Manufacturer in Serdang.

The following Factory Inspections/Checks were carried out :
1. Physical Inspection of the switchboard (Type of switchboard, thickness, Form of Segregation, etc.);
2. The specification of the accessories (MCCB sizes (normal rating, kA-rating, class), type and cable sizes, Ammeter, Voltmeter, Digital Power Meter (DPM), protection relays (OC, EF, ELR), CTs (ratios, class & burden), Voltage Surge Suppressor (VSS);
3. Grounding bar inside the switchboard (50mm x 3mm);
4. Size of Main Busbar (R, Y, B & N) where current density < 1.5A/sq. mm. 5. Functional Tests on the Circuit Breakers, Contactors, Relays, etc. 6. Dielectric Test on Busbars (Pressture Test using 2000Vdc for 1 minutes between Phase-Neutral, Phase-Earth).
5. Checking the operation of Power Factor Regulator and verify the sizes of capacitors installed;
6. Checking the Current Transformers (Ratio, Class, Burden);
7. Ensure that the labelling at each MCCB is correct

Upon completion of all tests, the test certificates were signed by parties witnessing the FAT.

Taman Serdang Baru, Serdang, Selangor.

Electrical Installation at Golf Resort - A Case Study

2008-07-21T00:34:00.000-07:00

Golf and Holiday Resorts have grown quite considerably fast in the last 15 years. This may be due to the economic boom experienced by the country and the world as a whole during those period.

As many resorts have been opened, competition to obtain membership to sustain the operating costs of the resorts get stiffer. Subsequently, Resort Managers had been forced to keep the maintenance costs to a minimum to keep the business alive. As the competition continues, one of the the easiest way to keep the operating cost low is by reducing the maintenance budget. This ‘hidden cost’ is very subjective and always fell victim to the resort managers as it is only known to those people who are directly involved in the maintenance activities.

There have been cases whereby Resort Managers had reduced the maintenance budget so much that has resulted in the quality of services offered by the resorts had tumbled dramatically. This has brought bad reputation to the resort.

Kukup Golf Resort (KGR) was one of our clients for a year between 2005 to 2006. We had carried out monthly Electrical Safety Inspection on its 11-kV and 415V systems during the 1-year period which ended suddenly due to Management Take-Over.
KGR is one of the four golf resorts in the country where we had offered our Safety Inspection Services for the past 10 years. The other three golf resorts under our list are in Selangor (1), Terengganu (1) and in Johor (1).

In my opinion, I believe Resort Manager had not put much emphasis on the requirement of Malaysia Electricity Acts 1990 (Act 447) and Malaysia Electricity Regulations 1994 when managing their respective resorts. The management has been iformed by their respective ‘Competent Person’ that failing to comply with the Act and Regulations, they are liable to be charged (penalty) for RM10,000 and RM1,000 per day for every day of non-compliance. In a real term, if this was to be calculated, a resort which has been operating for the past 5 years without complying to the Act 447 shall be penalised to pay an amount equal to RM10,000.00 plus RM(5 x 365 x 1,000) = RM 1.835 million !!!!

Some of the most common non-compliances by the Golf Resort’s Management are :

1. Does not employ the right category of Competent Person;

2. The registration of installation (including Generator Set) has expired;

3. Protection Relays re-calibration was not carried out;

4. Illegal wiring carried out by non-Competent Person;

5. Switch Rooms have been converted to Temporary Stores;

6. No as-built drawings to be referred to during power failures or break-down;

7. Switch Rooms are not kept locked at all times;

8. House-keeping of switch rooms are hardly or never carried out at all;

9. No testing at a five-year interval has ever been carried out ;

10. Provision of tools to maintenance staff is inadequate.

The above general remarks are equally true to most of the golf resorts and other installations (factories, ware-houses, complexes, etc.) inspected monthly by our Competent Electrical Engineers. Those are similar remarks written monthly inside Form I which were sent to the Energy Commission of Malaysia for record and further action.

I sincerely hope that all managers of any premises (golf resorts, factories, installations, etc.) to take note and treat the requirement of the Act 447 is equally important to the provision of the best facilities to your clients. Please take note that all hard works done by your F&B and Marketing departments will render useless once the electrical installation at your premises experiences a major break-down or fault due to poor maintenance caused by very low maintenance budget.

Examples of electrical accidents happened to KGR two years ago (shown in the photographs below) should be a lesson to all other resorts.

The after-effects were :

1. Cancellation of functions (loss in revenue);

2. Bad reputation to the resorts

3. Damage to perishable food stuffs;

4. Penalty to be paid to the Energy Commission (Suruhanjaya Tenaga) for non-compliance of the Act 447 and Electricity Regulations 1994;

5. Injury to personnel/staff

So, since money is not everything in life or business, the quality of electrical installation must be taken care of by the right Competent Person required by the law to ensure that the facilities at the resorts is well-taken care off and are always in a good operational condition.

Further details on facilities available at KGF could be obtained from the following web-site : http://www.kukupgolfresort.com.my/facilities.html

Transformer Oil Dielectric Test

2008-07-21T00:16:00.000-07:00

This is one of the tests carried out on oil-immersed transformer (Oil Natural or ON). The mineral oil used acts as a coolant and insulator to transformer windings.
The dielectric test is carried out to check whether the dielectric strength of the oil is still within telerable limit i.e more than 30-kV after six (6) times voltage injection across 2.5mm gap (as per IEC standard).
The procedures to carry out the tests are as follows :
1. make sure the transformer oil temperature is relatively cool (about room temperature);
2. identify the location of sampling valve;
3. open the outer protective valve cap;
4. loosen the screw (valve) slowly until droplet of oil appears to flow out;
5. wet the inside beaker with oil by letting the oil flow into the beaker (rotating the beaker);
6. after the flow of oil into the beaker is constant and the beaker is about 20% full; throw away the initial oil;
7. slowly start the oil sampling by letting small jet of oil to flow into the beaker through the side wall;
8. make sure that the flow is smooth and no bubble is collected;
9. collect enough volume of oil into the beaker (at least 50% full)
10. once the sampling oil is adequate, wipe the outside beaker with clean rug/cloth
11. insert the beaker into the test compartment of the Oil Test Set
12. switch on the oil test set
13. select the desired standart of oil test
14. press the start button

The oil test will be carried out automatically by the set. The test is carried out by :
a. stirring the oil inside the beaker for 5 minutes;
b. slowly increase the voltage across the gap until the flash-over occurs
c. the voltage at which flash-over occured is the dielectric break-down voltage
d. after the flash-over, voltage will be cut-off
e. the fan will stir up the oil again for 2 mintes;
f. after 2 minutes has been reached, the voltage will be increased again until flash-over ocuur again;
g. this will be the second break-down voltage;
h. the 2-minute stirring and voltage injection test is repeated for another four (4) times;
i. after a total of 6 tests have been carried out, the average value is taken.

If the average break-down or flash-over voltage value is > 30-kV, the Oil has PASSED the test and likewise if the average break-down voltage is less than 30-kV, the oil has FAILED the test.
If the oil test fail, the oil can still be saved by carrying out Oil Filtration process. This service could be engaged from Electrical Service Contractor who has an Oil Filtration Machine.

Testing & Commisioning 11-kV Sub-station

2008-07-19T21:22:00.000-07:00

Typical 11/0.433-kV sub-station building (attached)

11-kV sub-station building normally houses 11-kV switchgear (Circuit Breaker, High Fuse Unit (HFU) or Load Break Switch (LBS), 11/0.433-kV Distribution Transformer and 415-V Low Voltage Switchboard. This three-room building normally measures 35' x 15' (10.6m x 4.6m) by TNB Standard or 39' x 15' (11.9m x 4.6m) according to JKR Standard.

As this building is the source of electricity supply to a new project, there is always an urgency that all the equipment be installed and commissioned before the other Mechanical and Electrical (M & E) equipment in the building are tested and put into service.

Thus, it is very important in all projects which receive the 11-kV supply (whether from TNB or exisiting 11-kV Main Intake Sub-station (MISS) or Main Switching Swithing (MSS) or Stesen Suis Utama (SSU - in Bahasa Malaysia) to properly test and commission every equipment installed inside the 11/0.433-kV sub-station before energizing or switching on the 11-kV supply to the said sub-station. This is imperative to ensure that the 400-V stepped-down 3-phase Low Voltage (LV) supply to be used for the Testing and Commissioning (T&C) of M&E equipment in the project does not experience any disturbance or causing any danger or untoward accident to the contracting personnel.

According to the Malaysia Electricity Regulations 1994, before any electricity supply to be given to a new premises, Forms G and H must be submitted to the Supply Authority for record and approval.
Form G denotes that a Competent Person has duly verified that he or she has carried out the supervision of the installation works (and it has been done according to the safety rules and regulations) while Form H submitted by the Competent Person who had confirmed that all tests have been carried out on all equipment which are to be energised and he has confirmed that it is safe to switch on the electricity supply to the 11-kV switchgear, transformer and LV Board.

Some of the basic tests on the equipment housed in the 11-kV sub-station are :

A. 11-kV Switchgear (Circuit Breaker or RMU)
1. Insulation Test 1 : using 5-kV DC
2. AC Pressure Test for 1 minute (record leakage current)
3. Insulation Test 2 : using 5-kV DC
4. Vacuum Check (if Vacuum Circuit Breaker is used)
5. SF6 gas check (if SF6 CB is used)
6. Calibration of all out-going circuits protection relays
7. Calibration of protection relays according to settings approved by TNB or Consultant
8. Insulation, Ratio (and pressure test) on 11/0.110-kV Potential Transformer
9. Insulation Test on incoming 11-kV cable (5-kV DC)
10. Pressure Test on 11-kV XLPE Cable (Very Low Frequency (VLF) = 19-kV AC for
60 minutes/phase)
11. Tripping Test on Transformer Alarm and Trip Temperatures
12. Verify and Test Earth Resistance

11-kV SF6 Ring Main Unit, Vermin-proof netting,
Grounding Copper Tape & Ventilation Louvred Opening

B. Distribution Transformer
1. Insulation Test (P-E, P-S, S-E)
2. Ratio Test (at every tap, 1 to 5)
3. Insulation Test on Primary and Secondary Cables
4. Verify Star-pint Neutral earth point and pit

11/0.433-kV 1000KVA ONAN Transformer : Alarm

& Trip connection; trenching, cable support

C. Main Switch Board (MSB or LV Board)
1. Calibrate all protection relays
2. Insulation Test on all out-going cables
3. Insulation Test on the main busbar
4. Check Earth Resistance
5. Ensure Voltage Surge Supressor (VSS) is earthed accordingly.

1600A 415-V Main Switch Board : relay
calibration, as-built drwgs, label, panel opening

Once all the test results are produced and verified by the Consulting Engineer/Designer and all tests have been verified by the Service Engineer, then only the 11-kV electricity supply be switched on the incoming Circuit Breaker/LBS.

There are other basic and important requirement such as Danger and No-Entry signages, 11-Kv and 415-V Switch Boards labelling, Rubber Mat, CPR Intruction Manual, As-built Diagram, etc. must be installed before or once the switchboards are energised.

Photographs below show some of the defects or non-compliances to Electricity Regulations of an 11-kV installation which has been energised !!!
It is hope that immediate actions are taken by the Project manager to ensure that the 11-kV installation does not cause any danger to the operating personnel within the vicinity of the 11-kV sub-station.

Some of the defects observed at the energised 11-kV sub-station are :

A. 11-kV Switchgear (Circuit Breaker or RMU)
1. There is no label at Ring Main Unit - Danger sign, etc.
2. Incoming and outgoing 11-kV cables are not properly or firmly supported;
3. 11-kV trench is still littered with waste materials (paper, wood, plastic, etc.)
4. No as-built drawing framed at the wall of the room;
5. LV Board shares the same room with the HT equipmnt (problem of competency personnel)
6. Louvred windows to be fitted with SWG23 Mesh 10 vermin-proff wire netting
7. Earth pit for 11-kV RMU earthing is not found/could not be located (identified)
8. 11-kV Log Book is to be provided
9. Temperature Alarm & Trip facilities at the RMU - could not be verified
10. Trench cover must be provided and the trench shall be filled with clean river sand
11. To test and verify Earth Resistance connected to HT panel

B. Distribution Transformer
1. 11-kV Primary cable termination is a bit doubtful (saddled with wood)
2. Cable trenches are not properly constructed and covered
3. Secondary cables (415V) are not properly saddled/bracketed to the side walls of trench;
instead the cables are 'pulling-down' the bus-bar attached to cable termination flags
4. PVC/PVC green cable used as star-point neutral is not properly terminated/linked/welded
to the earth electrode at the earth pit;
5. To verify whether the Alarm and TRip contacts are linked to the Ring Main Unit (RMU)

C. Main Switch Board (MSB or LV Board)
1. All protection relays were not calibrated by Service Engineer
2. Some of front metal panels could not be closed due to misalignment;
3. MCCB panels must be correctly labelled;
3. Short-circuit Current Rating (Isc) of some MCCBs are not 43-kA minimum
4. Power Factor correction capacitor bank is to be tested and commissioned
5. Cable trenches c/w cover is not properly installed (debris still littered at the bottom of the
trench)
6. Log book is to be provided;
7. CPR instruction framed-poster is to be installed inside the LV Room.

11/0.433-kV Tx : grounding pit, cleaniness,

cable trench, trench cover

Note : It is not the intention of the Inspector to find fault on the project execution. As a Service Electrical Engineer, I would like to say that legally and for safety sake, the sub-station and its related components SHOULD NOT BE ENERGISED YET as there are still impending job such as relay calibration, labelling, trench works, etc which were not done yet but are VERY IMPORTANT to ensure safety to the equipment and personnel handling it.

ChanSowLin-SgBesiCamp-170708