Transformer Feeder Trip Disebabkan Hi Set EF Ketika Energization

Ketika nak ON Transformer pertama kali, kadang-kadang ia akan trip pada hi set EF. Kadang-kadang tak, boleh ON macam takde apa2.

Transformer Magnetizing Inrush - Apa yang berlaku?
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Transformer besar atau kecil, tetap akan ada inrush untuk magnetizing core transformer tersebut. Nilai inrush berbeza-beza dan tidak tetap, dan bergantung kepada keadaan sebelum nak energize... contohnya adakah transformer baru dibuat DC test seperti insulation resistance test pada windingnya, dan sudahkah ia dinyahcaskan sebaik mungkin. Jika tidak dinyahcas dengan betul, akan ada tinggalan DC tersebut (remnant magnetism) yang mana akan berlawan sebentar pada awal energizing dan inrush boleh mencapai lebih tinggi dari biasa.

Bila energize-trip-energize-trip-energize-trip... hingga berjaya, nilai inrush tersebut semakin berkurang... sbb setiap kali energize tu, dia sudah charge sikit demi sikit core transformer tersebut. Tuan boleh perhatikan pada Generator + Step Up Transformer, bila start generator bersama transformer tersebut, tiada inrush yang berlaku sbb voltage build up dari terminal generator bermula dari zero dan naik secara perlahan sehingga ke full voltage.

Kenapa biasanya trip EF Hi Set?
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Ketika energizing, nilai inrush pada ketiga-tiga phase tidak sama. Biasanya 2 phase (R,B) lebih tinggi dari Y atau sebaliknya bergantung kepada construction core transformer. Tuan boleh search pasal

Electrocution Case Cameron Highlands LPG Water Heater - What could be the causes?

Peace be upon all of us,

On 10th of March 2022, a couple was found dead  in their flat unit at Taman Puncak Tringkap, Brinchang, Cameron Highlands. Based on the post mortem, the couple is believed to have died from electrocution.

The water heater used was actually LPG (Gas) type water heater and not the electrical type instant water heater. Up to today, there has been no official investigation report on the cause of the incident i.e. how the gas water heater could have became Live with electricity.

LPG Type Water Heater

The LPG water heater uses gas as a fuel source to heat up the water. When the water reaches the magnetic switch, the sensor notifies the solenoid valve, which then turns on the gas pipeline. Once the gas flows into the burner, it triggers the igniter. The igniter sparks and gas flames appear. The cold water flows into the heat exchanger, which is then heated. For more details on how it works, please refer here.

The only electrical part within the LPG Water Heater is the igniter, which normally uses 1.5V or 3V battery as the ignition source. 

So, what are the possible causes for LPG Water Heater to become electrically Live?

Above is a typical electrical system in an apartment and its earthing interconnection. There