Planning

17-28 may 2010

iii.Planning

In other Organization in the world; specially those related with technical activities, planning unit plays very important roles. The planner has to make sure that every single plan they approved is according to the specification, meet the safety requirements and cost efficient which can prolong the life span of the equipment plus put a stop to undesired accident. TNB also did the same thing.

Ø The job scope of planning engineers is to:-

· Plan the construction of substation for new projects.

· Determine the suitable route for new manhole to be connected with the existing manhole.

· Prepare a 5-year Distribution Network Master Plan (DNMP) which contains load forecast in Putrajaya and Cyperjaya for the next 5 years.

· Certify materials used by electrical contractor meet the standard brand required by TNB.

· Monitor the timeline of projects to avoid time delay which is not cost effective.

Ø Before any projects can be executed,the planner will determine which suitable category it should be with.

Ø There are two types of category:-

· BKKM (borang kerja-kerja model)

· LKKK ( lembaran kerja-kerja kecil)

Ø In both projects,there are a few attachments that must be submitted to the planner in order for them to calculate:

· Maximum Demand (DM).

· Electrcitiy tariff

· Cost incurred

· Date of completion from time reviewed

Ø The attachments will prepared by the technicians are as followed:

· SJHT (Senarai Jadual Harga Tetap)

· 11 KV network diagram.

· Load analysis using PSS ADEPT.

· Cable route using GIS.

· CD (Cadangan Daerah).

The reoson that I didn’t write deeply on the planning section because all the planning forms and procedures are done by the bahasa malayu language only,so that I just wrote the general and main idea only.

Construction

ii.Construction

3-14 may 2010

My first day in the construction was on 3/5 till 14/5.i met the head of the construction unit EN.mukhlis bin zulkipli ,,I have a bit talk with him as I have an idea about the distribution and the power planet from the maintenance department.

He explained to me in brief the normal mission of the construction unit which is:-

Firstly the unit will handle the project after the design/plans are approved.

Secondly the unit is responsible to make sure that all civil infrastructure (manholes, ducts, and substation) and electrical equipments (cables, transformer, switchgears and feeder pillar) are being installed following the correct procedures.

Thirdly the unit are responsible to do a switchgear shutdown, identified the cable to be cut and joined before issuing PTW (permit to work) to contractor.

Then mr mukhlis bin zulkipli got busy with a visitors so that he pass me to the leaders of the construction team mr Termizi and mr,azizul to continue what he had started and earn more info by taking me to some new project which are still under procedure.

Mr Termizi describe how risky and danger are them function because if there is any wrong it cause power supply outage to the customer and it may also cause bad incident for the contractor, for the sake of the power supply incident there are a mandatory steps that the construction unit must follow it which are:

1- Identify substations and normal off point (NOP) in the loop that related with the project to ensure continuous power supply for correlated customers.

2- Authorized person must issue permit to work before the contractors start working and cancel it after the job is completely done.

3- The competent person and the authorized person are taking the taking the full responsibility because there are the only persons who are doing the switching and normalization of the supply system.

During the 2 weeks in construction unit I have learn several things which is:

1- Loop in loop out (LILO) CABLE.

2- Adjusting the underground cable.

3- Fusion connection

4- Cutting ,Joining ,changing the Underground cable

5- Tests done on the cable.

Loop in loop out (LILO) CABLE.

Cable (LILO) is a common project in new industrial park. The main objective is to connect new cables with the existing one and make a new joint. And the procedure is:

Shutdown the power supply: - this procedure is done on the cable involved to make sure no current discharge that could harm the worker.

Normal off point: - is move to a new point in order to maintain the power supply of current customer.

The cables are jointed together and loop into the system.

Adjusting the underground cable :

Ø Distribution cable to the customer

Ø The cable is step down from the substation with 11 KV 415V then its spreads into (MSB) mother Switch Board of each host/house.

Ø Mother Switch Board (MSB)

· Deliver 240 to the plug port

· Contain fuse ; avoid damage to the cable plus its more safety and costing less money.

Ø Steps to install a distribution and the feedback cable :

· Redraw the underground cable

· Plan and Predict for all possiblities in the future.

· Interconnect and install the cable.

Ø Advantage of feed back box distribution cable:

· Easy to trouble shoot

· Maintain service to customer all the time.

· Minimize the danger for technician and easy to connect.

Ø An example of cable redraw and how the feedback Box are working and helping to feed back the supply

· feed back box always on OFF .

· if the supply is OFF from the distribution box the Feed Back box automatically will turn ON

· if there is a maintenance or break down between point 1 and point 2

¾ Firstly they turn OFF the distribution and the feed back as well the

¾ Secondly they will cut OFF the supply at point 1 and 2 .

Then they will TURN ON the both Boxes and the supply will passing through the circuit except the line which is between Point 1 and 2.

Fusion connection

Ø T

here is 2 types of fusion :

Cut-Out fused :- 240 v

Its 3 phase and single phase connecting to the switch board.

J-Slotted fused

Ø Steps of connecting the fuse and the 3-phase rotation device :

· Fuse :

¾ Release the black screw till the end.

¾ Put the fuse between the holder.

¾ Balance and close the black screw.

· F

· 3-phase rotation device :-

¾ The device contain 3 cable (Red, Yellow, Blue)

¾ Connect each color to the right position in feeder pillar .

¾ Check the devices if its rotate in clock wise .it means the connection is correct ,,if moves in comer clock wise it means the connection is reversal.

Cutting ,Joining ,changing the Underground cable :

Ø TNB is supplying electricity to consumer in putrajaya and cyperjaya region by underground cable .

Ø The procedure of cutting ,changing or joining are :-

¾ Use the CABLE IDENTIFICATION SYSTEM

¾ Take out the water from underground by the blower.

¾ Use the Hydrolic cutter to cut a big width cable from far distance for safety purposes.

Ø

Steps of using the cable identification system:-

¾ Connect the transmitter to the feeder.

¾ Use the receiver and tong to indicate the flow of current to know which cable

has no current flow to cut it.

Steps of using Hydraulic cutter:-

¾ after indicating the cable which is out of the current flow.

¾ Evacuate the worker and the technician from underground.

¾ Press frequently the hydraulic cutter and look to the meter indicator the indicator will arise to current point then get back to the zero.

¾ Go down to the underground ,,check the cable by the following tests which I

illustrate it down ,,then join it back.

Tests done in the cable.

1. Phasing Resistance Test.

Ø To test and identify the phase of underground cables.

Ø Also to make sure the phase of underground cables is in correct sequence.

2. Continuity test

Equipment: mugger

Objective: to determine if a complete electrical circuit can be established between two points. The circuit under test is completely de-energized prior to connecting the apparatus.

Maintenance

i. Maintenance

19-30 of April (2 weeks)

Distribution

Basically 11 kV network is the main distribution voltage used by TNB. The 11 kv is stepped down from the 33 kv transmition voltage via power transformer in main intake distribution substation (PMU-Pencawang Masuk Utama) from the PMU the 11 KV is distributed into many feeders via main switch station (ssu) and each feeder consist of a few substance (PE) of 11 KV that stepped down to 415 V via step down power transformer. Sometimes PE called RMU switch gear.

There are various types of customers using the electricity with different voltage and phases :

Ø they use single

phase 240V for the normal houses.

Ø 3 phase 415V. For the consumption of high load in a three phase load such as a commercial category,

Ø For the industrial category there are 2 types :

I. LPC (large power consumer) which are 3 phase

2. 11KV directly from transmission line,

- 3 phase 33KV

Main intake substation PMU and main switch station SSU

The main intake substation (PMU) is a node for terminating and reconfiguring transformer that step down 33KV voltage to 11KV voltage (primary distribution level ) while the main Switch Station (SSU) is a node of terminating and reconfiguring the 11KV line of many feeders consisting of substation.

For the PMU and SSU sides,

the protection implantations at these sides are vacuum circuit breakers (VCB) .they are operated atomically when the current transformer sense the over current or the earth fault or maybe both of them ,and make the relay operate, while the mechanical part operates and motorizes the breaker option.

Substation PE

The electrical connection of the substation in putrajaya operated by TNB is in form of rings called Ring Main Unit (RMU), the connection is illustrated at the Sketching page.

The RMU switch gear is a ring main unit (rmu) connection of a switch that separates the feeder from the secondary distribution transformer.

Ø The substation consists of two main parts which are :

1. switch gear

2. transformer .

v Steps of how is the maintenance are for one of the substation in putrajaya, down is showing which substation they choose to maintain it.

o Substation no 17.05 feeder no 1 :

· Two teams are doing the maintenance

· The first team is to cutoff the supply from the substation 17.05 :

· Firstly they move to off point at ss2..01

· ON the switch feeder from OFF and keep the earth’s switch off.

· Moving to substation (PE17.04) to OFF the feeder from ON and remain the earth Switch OFF.

· Moving to substation (PE2.03) to OFF the feeder switch and remain the earth switch OFF.

· After making sure that all the feeder switch is OFF on the substation (to prevent any short circuit or fault) they turn ON the entire earth switch.

· Then at the substation (PE17.05) which want to service it first thing to make sure before starting the maintenance is to check the voltage indicator to know eitherthe voltage is still passingor dead

· If the light is on its mean there is still voltage atthe cable

· If the light is off it means the cable is dead.

· After cut off the supply the second team is starting the service after getting a safety rules from the person in charge.

Transformer service

During my visit to PPU located at precint 10, I have given a chance to see how MTM staff serviced the power transformer. On this day I went up onto the 11kv transformer and learned afew parts of the transformer such as:

Gas preservation system

Gas detector relay

Dehydration breathers

Oil to oil bushings

Power transformer that TNB usually use are on OTP (oil transformer planet) type. It is generally mixed with the Gas, water and contaminants. The content of the contaminants generally increase with time. In the oil treatment plants (OTP) these associated gases, water and contaminants are separated from the oil and taken away .in fact, it is electrically critical that the oil doesn’t contain too much of these substances. after treating the oil in the oil treatment plant, the stabilized oil is then again ready to be used in power transformer.

Tests

High voltage DC test.

Ø The tests are on switchgear to test the reliability of vacuum tubes on VCBs.

Ø Results :

1. Earth phase should be 240V.

2. Phase to phase voltage should be 415V.

3. The phase rotation must be red to red, yellow to yellow and blue to blue.

Insulation Resistance Tester.

Ø Tested to the cables and switchgear to check for possible leakage resistance failure.

Maintenance cycle

According to the maintenance policy, all the services for substation and main intake substation must be done according to the time cycle as well as the equipments brand. For example the 11 kV VCB (vacuum circuit breaker) of SIMEMENS or ABB must be serviced for every 18 months while VCB 33kv is 12 months from the time reviewed