how to calculate load for protection from Surge

[Asit]

Hi Mahiruha,

Very sorry to know about your problems. A few weeks ago during the last untimely storm, I also lost a modem/router and the Ethernet port of the home PC due to lightning. The PC had UPS protection, but the ADSL modem/router was not protected. It also showed that lightning can affect the telephone line and through it can harm Ethernet ports. I have since then replaced all damaged stuff.

What are you going to do repair the damaged articles? And, any measures for the future?

Regards.

PS: You must come and visit my place.

 

[westom]

I think the surge just fries anything that it finds in the first point of entry in to the electronics.

Which was the myth that blamed damaged modems on surges from phone lines.

In this locale, earthed surge protectors have existed on phone lines for well over 60 years. How are modems routinely damaged? Well, it is electricity. Therefore current flows through everything, simultaneously, from cloud to ground.

Yes, current had to pass through that power adaptor and electronics simultaneously. Much later, only something in that electric current path fails.

In modems, surge entered on AC mains, through motherboard, destructively through modem, then to earth ground via the phone line. A most commonly damaged part was a PNP transistor driving the off-hook relay. That was the path from AC mains to phone line and earth ground.

Those who know only using wild speculation assumed surges entered on phone lines. Only because that is the popular myth. We who do this stuff, trace the circuit to discover an incoming and outgoing current path. To have damage, an appliance must have both an incoming and outgoing path. Otherwise, no damage.

Lastly, nothing stops a surge. What does every effective protector do? From the NIST (a US government research agency):

A very important point to keep in mind is that your surge protector will work by diverting the surges to ground. The best surge protection in the world can be useless if grounding is not done properly.

What does the NIST define as useless? That Belkin protector.

 

[mahiruha]

Hi Mahiruha,

Very sorry to know about your problems. A few weeks ago during the last untimely storm, I also lost a modem/router and the Ethernet port of the home PC due to lightning. The PC had UPS protection, but the ADSL modem/router was not protected. It also showed that lightning can affect the telephone line and through it can harm Ethernet ports. I have since then replaced all damaged stuff.

What are you going to do repair the damaged articles? And, any measures for the future?

Regards.

PS: You must come and visit my place.

Hello Asit,
sorry to hear about your experience too. Broadly what I understood is that in case of lighning and sudden rise in voltage in electric supply lines can cauese lot of damage to the electronics and we really don't have a solution to it. I guess it is better then to insure them. I got the electrician to check the circuit breakers and he found some of them are not working and got them replaced. To be honest with you they don't offer much other than piece of mind since one of circuit brekaer actually got tripped and pc got damaged.Also as Venkat suggested I cheked with the electrician if the earhting was done properly and he assured me that it is done properly and a thick copper wire is connected to the mains where external supply comes.He will bring something to attach to the mains so that it will trip when there is a surge. I still don't know what it is but will know in few days.I am still in process of getting things repaired. Replaced the smps of the pc it is now working. One pcb of the tv where the power cord is attached completely got burnt the technician replaced it and and it is working now. I must say I am extremely pleased with the Samsung service they just fixed it within a day.Xbox I got a new one. Other things are in the process of getting repaired not sure if they can be repaired.
I will definitely come to your house.Really sorry for not being able to make there so far. My inherrent lazyness is the only thing to blame. Actually these days I am bit tied up with my niece and nephew 4 and 6 respectively. They are keeping me really busy with lot of antics.They are also the reason that I had to replace the xbox 360 immediately. There is a game called viva pinanta trouble in paradise. which three of us are playing together and I am being their mentor.
thanks.

 

[westom]

I got the electrician to check the circuit breakers and he found some of them are not working and got them replaced. To be honest with you they don't offer much other than piece of mind since one of circuit brekaer actually got tripped and pc got damaged.

Learn what a circuit breaker does. It does not protect any electronics. Circuit breaker trips AFTER damage happens. Its purpose is to protect you from fire AFTER electrical devices have failed.

Or let's put numbers to it. A destructive surge completes in microseconds. Circuit breakers take milliseconds to trip.

Circuit breakers provide human safety. A properly earthed 'whole house' protector is for transistor safety. Routine is to have direct lightning strikes and no damage. Even the protector remains functional. But only if that protector is properly located, properly sized, and properly earthed.

Every telco everywhere in the world has switching computers connected to overhead wires all over town. Does you telco discontinue service when thunderstorms threaten? No. Then your town is without phone service for four days as they replace that computer? No. Of course not. Posted here is the same solution used by every telco all over the world - even 100 years ago - so that direct lightning strikes cause no damage.

Every wire inside every cable must make that 'less than 3 meter' connection to earth before entering the building. All connected short to a same earthing electrode. That solution is why telcos can suffer about 100 surges during each thunderstorm - and no computer damage. Which is why munitions dumps suffer direct lightning strikes without explosion. The solution is that well proven and is that effective. And often not known by an overwhelming majority.

Your damage is typical when one fails to install this well proven solution. Lightning damage is directly traceable to human failure. Circuit breakers trip long after damage is created.

 

[ravin]

I was originally thinking of adding a 1KVa or 1.5KVa 650W UPS + surge protection (360 jourles) + voltage stabilizer (200v-270v) to connect my stereo system.

I know for sure that my house is grounded, and everythime it rains with heavy lightening, the lights go off....But otherwise, I don't really have any problem of brownouts or even blackouts.

Would a UPS still be recommended if I want 220Volts of uninteruptable power supply from the 900mAh battery to feed my int. amp. and cdp. How would it sound?...Or would the Belkin be the preferable choice.