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Fluctuating house voltage

Started by Johnnie F., Feb 25, 2019, 05:56 PM

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Johnnie F.

Quote from: ken kenobie on k-fI don't know if its just where I live out in the bush , but recently the mains voltage to the house seems to be fluctuating all the time.

Any one else suffering the same annoying house voltage problem

It's a huge problem almost anywhere out in the sticks; it will be felt especially in the summer months from March to June, when many people operate their air conditioners. Worst it is from around 7 to 9 p.m., when people come home from work and start their rice cookers. Then the voltage drops in some places even below 140V. At that voltage your air conditioner will eat full electricity but not cool at all, your fans might get stuck and the motors burn through etc.

There are AVR (automatic voltage regulator) available. but alas, if you don't plan carefully and get what you actually need, you might end up with even more problems than before. It needs to have sufficient power for your needs, or it might shut off all at voltage too low, and your fridge is without power until you notice the problem and switch manually. Only some automatically switch to "bypass" then.

Best are those with "pump" function, not just bypass, in case they cannot manage the step-up transformation. Those automatically switch to operation with capacitors instead of transformers, when the transformer cannot handle it anymore due to too much draft and too little input. They will eat a lot more kW, but keep things working.

I use a Voltage Step-Up Transformer I can adjust manually, and after that a medium size AVR, cost together about 30,000 THB. Makes up to  3 air cons and water heaters etc. still work fine, when much of Thailand suffers from too low voltage to cool down.

If I started from the beginning, I would buy this (only, instead of strong voltage step-up transformer and medium size AVR):

If you're already having problems, don't buy one of those cheaper AVRs. Good ones suitable to help air cons etc. cost 25,000 THB up. And don't expect them to lower your electricity bill. But they help to get what you pay for in any case!