Whole house surge protection devices

square_wave

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I live in an apartment and during the heavy rain season, surges can happen. I protect the audio gear via an eaton ups. But there are still many devices on the mains that are unprotected. I have been looking at full house surge protection devices from companies like Siemens, Eaton etc.

The kind of devices being talked about in this link :

Does anyone have experience with these ? Some of these devices like the Schneider Electric’s Square D even offer connected equipment warranty.
 
This is an interesting thread and I am also keen to hear the views and experience of fellow FMs.
Thanks square_wave for starting this.
 
I live in an apartment and during the heavy rain season, surges can happen. I protect the audio gear via an eaton ups. But there are still many devices on the mains that are unprotected. I have been looking at full house surge protection devices from companies like Siemens, Eaton etc.

The kind of devices being talked about in this link :

Does anyone have experience with these ? Some of these devices like the Schneider Electric’s Square D even offer connected equipment warranty.
Hi I had v bad experience of sudden power surge at my house.my ht equipment ,cctv everything blewup.ht though it was switched off but was connected to the socket.extent of damage only I could makeout once I switched it on.denon av receiver motherboard gone got it replaced.velodyne subwoofer same ,my Epson projector gone beyond repair,had to replace it with new one.cctv replaced everything.
For this I installed inhouse internal transformer about size of small box .it's 8 kv costed me about 65 k.now I feel secured and safe.no maintenance for that.
 
Is it for inrush current protection or transient current surge? Most audio equipment can take a CL90 thermistor in series to protect from inrush current. For protecting from surge you can add a 250v MOV across Line and neutral for surge protection.

If voltage go above that the MCB will trip.

In case of thermistor it's internal resistance will be high initially and after a few seconds it will be low and eventuall be short. So high surge currents will be absorbed.
 
Don't newer MCBs protect against some amount of inrush?

Cheers,
Raghu

I dont think they help with incoming surges. They help when your gear misbehaves electrically and they shut down the line. Maybe an electrical engineer can comment.

‘B’ Curve MCB is used on lines that supply domestic appliances with mainly Resistive Load.

‘C’ Curve MCB with mainly Inductive Load. Pumps, air conditioners etc.
 
Cheers,
Raghu

This is what I see online for D curve. This type of MCB trips between 10 and 20 times full load current. These MCBs are use in specialty industrial / commercial uses where current inrush can be very high. The common applications include transformers or X-ray machines and electric motors.
 
I will try to explain.My writing skills are all over the place , so please excuse..

B curve: 3 to 5 times the rated current, followed by C curve at 6 to 10 times and D curve at 10 to 15 times.

Inrush and over load are two different things.

Equipments like motors etc have inrush current of many times the normal current which lasts only for a small time at start up.
So the breaker supplying them should be capable of withstanding it to avoid trip at startup.

For example, a C curve,10 A MCB will withstand 60 to 100 amps but a B curve breaker will only withstand 30 to 50 amps for a short period of time before it trips.However both of them will trip above 10 Amps on a long time.
The whole idea is to protect the load but at the same time avoid nuisance trips.The curve type also dictates the short circuit current (i.e current caused by a fault or a short in the cable,equipment etc..)the breaker will withstand before it trips.
Hence the MCB chosen for a load will depend on the type of load, normal current it draws and short circuit currents in the location of the equipment.Hope this makes sense.

Surge Protection
Now coming to SPD or surge protection devices,
It protects the equipments in your house from any incoming surge from the street service mains/supply line.This can be a switching surge, a lightning surge etc.Most Surge protection devices operates in a sacrificial method where it shots the phase to ground and destroy itself .They are wired such that one end takes the phase and the other end is grounded. The SPD will remain open in a normal operational scenario i.e normal voltage. But when a surge occurs , the voltage increases and the SPD will conduct the current to ground thereby diverting the energy to ground before it reaches your equipments .They are varistors that conduct electricity only after a certain voltage.

But please note, Nothing can save your equipment's if it is a direct or nearby lightning strike.The energy is so high that, it would destroy the SPD as well as your equipment.The only safe way is to unplug the equipment's from the wall socket when not in use or during a storm atleast.

I have seen very bad results of lighting strikes at commercial installations despite of their over the top lightning and surge protection systems.
 
I will try to explain.My writing skills are all over the place , so please excuse..

B curve: 3 to 5 times the rated current, followed by C curve at 6 to 10 times and D curve at 10 to 15 times.

Inrush and over load are two different things.

Equipments like motors etc have inrush current of many times the normal current which lasts only for a small time at start up.
So the breaker supplying them should be capable of withstanding it to avoid trip at startup.

For example, a C curve,10 A MCB will withstand 60 to 100 amps but a B curve breaker will only withstand 30 to 50 amps for a short period of time before it trips.However both of them will trip above 10 Amps on a long time.
The whole idea is to protect the load but at the same time avoid nuisance trips.The curve type also dictates the short circuit current (i.e current caused by a fault or a short in the cable,equipment etc..)the breaker will withstand before it trips.
Hence the MCB chosen for a load will depend on the type of load, normal current it draws and short circuit currents in the location of the equipment.Hope this makes sense.

Surge Protection
Now coming to SPD or surge protection devices,
It protects the equipments in your house from any incoming surge from the street service mains/supply line.This can be a switching surge, a lightning surge etc.Most Surge protection devices operates in a sacrificial method where it shots the phase to ground and destroy itself .They are wired such that one end takes the phase and the other end is grounded. The SPD will remain open in a normal operational scenario i.e normal voltage. But when a surge occurs , the voltage increases and the SPD will conduct the current to ground thereby diverting the energy to ground before it reaches your equipments .They are varistors that conduct electricity only after a certain voltage.

But please note, Nothing can save your equipment's if it is a direct or nearby lightning strike.The energy is so high that, it would destroy the SPD as well as your equipment.The only safe way is to unplug the equipment's from the wall socket when not in use or during a storm atleast.

I have seen very bad results of lighting strikes at commercial installations despite of their over the top lightning and surge protection systems.

Thanks for such a great explanation. What is your opinion about the non sacrificial devices like Surgex which clamps down on voltage surges ? They seem to be quite popular among the professionals
 
Hi @square_wave ,

To be honest I am not sure.There is not much said in their documents.I am not sure how do they absorb the energy of a surge like a lightning strike without providing a path to ground.They could be just an EMI/RFI filter by the looks of it.They do talk about current limiting , 6000 volts etc but their manual lacks explanation to back it up or I am not getting it right.
In the documents, they talk about better performance of the AV equipment not protection.I could be wrong here.

In my opinion if you want to protect all equipment's or even only the audio equipment,the best approach would be a proper surge protection device at the point of entry of the service mains to your switchboard. This is where the surge should be blocked/diverted.You dont want it to enter the wiring at all.This way you protect all the equipment's along with your audio equipment with the same cost.An additional EMI/RF filter can still be added for you audio anyway if required.
 
Check out EP 2050.

Intending to buy this. With EP2050 installed, I can safely plug the power chords directly into the wall outlet.
 

Check out Siemens FirstSurge too.

The advantage with EP 2050, is that it’s design is advantageous to audio as Prem has indicated.

Siemens first surge costs Rs. 40k ( that is the lowest price on Amazon and ranges from 40k to 65k with different sellers; not sure what the price is if one contacts Siemens directly ) while EP-2050 costs Rs.60k without customs duty.

I am not yet decided on which one to go for or just stay with the sound foundation barracuda distribution box which is connected to my audio system. Add one more for Rs.10k for my home theatre gear. These are the two systems for which I would need surge protection.
 
For excellent sound that won't break the bank, the 5 Star Award Winning Wharfedale Diamond 12.1 Bookshelf Speakers is the one to consider!
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