6 APRIL 2011

After having my breakfast, I went to a 'Pencawang Pembahagian Utama (PPU)', Batang Kali. I went there with Mr. Mohd Hafizi, Mr. Taufik and Mr. Amir. The main purpose of going there is because of Mr. Amir and Mr. Taufik have to take load reading at the PPU. They have to take load reading every one hour until 10 pm. I took the opportunity to learn about the PPU.

PPU Batang Kali is the smallest PPU in the region of Rawang.

PPU Batang Kali

The electric supply of PPU Batang Kali come from two sources that is from 'Pencawang Masuk Utama (PMU)', Rasa and from overhead (o/h) line. From the overhead line, the electric goes to overhead line box in the PPU.

O/H line box

O/H incoming

O/H outgoing

Then, the electric will flow to transformer, in order to step down from 33kV into 11kV.

stepdown transformer 33kV/11kV (TX2)

stepdown transformer 33kV/11kV (TX1)

After flowing into the transformer, it will flow into circuit breaker. PPU Batang Kali didn't use overhead line as their main electrical source, so at the circuit breaker it will open circuit for electric that comes from the transformer. The circuit breaker only short circuit for current that comes from PMU Rasa.

Circuit breaker

electric supply from PMU Rasa

Open circuit

At the circuit breaker, there is an ammeter that showed the load reading. There is certain current load, if the load exceeded the limit, the circuit breaker will trip.
example:
     - CT ratio: 600/5
     - setting: O/C: 2.5A, 50%, 0.1 (over current)
                   E/F: 1A, 20%, 0.1 (earth fault)
     - So. the max carried load is 300A.

 Tag for CT ratio with O/C: 50%

Tag for CT ratio with O/C: 100%

After the circuit breaker, the current will be distribute to the building around the PPU.
In the PPU, there is two more chamber. One of the chamber is consists of tap change, control panel and battery charger. The tap changer's function is to maintain voltage to be 11kV all the time. This is important to avoid overload voltage that will break down electrical appliance in the residence, but at this PPU, the tap changer switch is already broke down, so the switching will be run manually. The switching only happen when there is a report from the residence. The control panel will control the transformer while battery charger will charge wet battery that is in the other room. If there is 'black out', the battery charger will provide current for the PPU.

The two chambers in PPU Batang Kali

Control panel for TX1 & TX2

Battery charger

Spare charger

Wet battery

At the evening, I continue my study on the PSI. For this evening, I have covered 6 topics that is ‘PROSEDUR PERANCANGAN PENYALURAN BEKALAN VR (SERBIS)’, ‘PROSEDUR PERANCANGAN PROJEK SISTEM 33KV BAGI PENCAWANG PEMBAHAGIAN UTAMA (PPU)’, ‘PROSEDUR PROSES PERMOHONAN LAMPU JALANRAYA MENGGUNAKAN PEPASANGAN TNB’,  ‘PROSEDUR PROSES PERMOHONAN BEKALAN ELEKTRIK SECARA BIASA’, ‘PROSEDUR MENYEDIAKAN UNJURAN BEBAN DAN SERAKAN BEBAN UNTUK NEGERI’ and ‘PROSEDUR PENGURUSAN PERMOHONAN & PENYALURAN BEKALAN KE LAMPU AWAM’. 


That's all.. =_+