I guess what you are calling RCBOs are RCD safety devices. These are just to protect people from getting zapped, and do not prevent surges.buksida wrote:We have a major problem in our area with power supply, the existing transformer is seriously overloaded and goes bang at least once a week resulting in a 3-4 hour power outage.
That would be tolerable but the power dips and surges have caused a number of household appliances also to go bang including computers and my thirty thousand baht Yamaha amp.
The electricity board will do nothing about it, UPS units do not help, I have two 8 breaker consumer units with RCBOs but they dont help - is there anything that can be done?
The frequency of a power grid is closely maintained, it will not fluctuate more than about 0.1%. It is a combination of voltage drop and subsequent spikes and surges that is causung the damage.STEVE G wrote:I wonder if it's possible that if the system is overloaded completely, the frequency is starting to drop which will potentially cause damage to some electrics. If that is the case, I imagine that it's hard to protect against short of doing something like installing a large pure sine wave inverter similar to what you have with a solar power set up.
The voltage stability in any supply system is influenced mainly by the fluctuating load. At the lower voltage distribution point transformers have a limited range of self regulation. Grid supply transformers have automatic tap changing equipment to help maintain their output under varying load conditions. The problem being asked about here comes down to inadequately sized local street transformers, in addition to undersized and excessively long conductor runs. Therefore, it is not unusual, or unexpected, to find small changes in voltage levels, as the load is constantly changing, even in well designed systems.Yes, I agree that the frequency should be fixed in a perfect world, as should the voltage:
Yes, the operative words here being: MAY OCCUR. And some of those are dependent on some of the others!A list of severe phenomena which may occur and can cause wide-area
interruption or total system black-out are as follows:
Even with a big transformer on a pole right outside your front gate, there is is still the possibility of spikes that are sufficient to damage sensitive equipment. The only way around having some form of UPS combined with filtering equipment, is to completely isolate the sensitive equipment from the mains and have a dedicated source just for that equipment. This would have to be either a solar system, or a small motor driven generator, which is not really practical. Rather than a multitude of small UPS units it may be better to consider just one commercial type with sufficient capacity for your electronic gear.buksida wrote:Still finding fried appliances this morning.
I knew there would be no easy or cheap solution to this, buying a UPS/voltage regulator for each device that's plugged in isn't practical, unplugging them all every time is a royal pain.
Looks like I'll have to round up the neighbours and give hell to the EB.
There's a large steel mill at Ban Saphan Yaia:http://www.ssi-steel.com/en/abt/abts.htmIs there any close by industrial type loads, such as a freezer factory or similar, that may be causing spikes while switching equipment on?
