Digital Stabilizers - Horrors in our Apartment

[hifiashok]

So if we focus only on the SURGE protection part, what are the recommendations?

Belkin is the best, 'reasonably priced' available bet (IMHO)!

 

[hifiashok]

Don't these components like amps have built in protection? IIRC lyrita pre/ power amps do have fuses and such protection, not too sure though.

I think protection against surge can be done for the entire house quite cheaply.
Protection against voltage variance between 150-250 kind of range is the domain of stabs.
I asked my local electrician yesterday and he said manual stabilizers from companies like logicstat are good and they cut off immediately if voltage exceeds the set range. I am not convinced though about response time. He said servos would be very noisy.

a house-hold fuse working the way it should depends on its quality (time taken to blow). if the spike crosses it before/while it is blowing (that happens with low quality fuses).....

 

[balakrishna]

Buy SURGE X.

 

[hifiashok]

well i use.. normal spike protectors.. and ups..

and that works..

i had 2 ups lying unused got the battery replaced and both of them have a fuse as well as backed up with a spike protector..

nomal 500va ups gives 20mins back up for tata sky HD and LCD together with medium backlight. (that i have tested )

a UPS is not a good choice for AV (esp. hifi). A CVT is a better bet (not from a backup but a power conditioning perspective), provided you are able to keep it as far away from the audible area as possible.

 

[theironhorse]

a UPS is not a good choice for AV (esp. hifi). A CVT is a better bet (not from a backup but a power conditioning perspective), provided you are able to keep it as far away from the audible area as possible.

that is one issue of staying flat... space constraint..


i am planning to get invertor since months but unable to identify place to keep it..

 

[sridhar-v]

There are some essential points which everbody is missing:-

1. Every electrical item has something called a response time.
2. To fry you electronics takes a few milliseconds of high voltage/high current.

Now for the facts:-

Relay operated systems (unless they are using expensive solid state relays) take between 50 -100 milliseconds to act.
MCBs & ELCBs also have a similar time response.
Servo stabilisers can take upto 200 milliseconds before they start acting. Most low cost ones get into the act in about 500milliseconds.

So you use what I call the high voltage rupture discs (electrical engineers amongst you can let me know the exact technical name please!). The almost instantaneously close the line & neutral when voltage rises beyond the set value. This gives time for your MCB/ELCB to kick in. No current passes upstream of the ruptured disc. Have experienced this umpteen no. of times & saved lakhs of rupees in potential damages.
I have not seen any current ratings on these units. But I know that they are available in various voltage ratings.

PnReddy: Yes for 3 phase connection you will have 3 units across each pair of phase & neutral. But this will be only single phase protection individually. If you are using a 3 phase 440 V unit you do not require this. What you will require is a single phasing cut-out.


Sridhar

 

[rana_kirti]

I saw Crossword selling Belkin Gold Series surge protector in Bangalore Airport. They give you 1 lakh compensation also.

Cheap Belkin 8-Out Surge Protector Gold Series sales India | Belkin 8-Out Surge Protector Gold Series Themes | Belkin 8-Out Surge Protector Gold Series Accessories review

I dont know if UPS is a good idea, will let the experts answer it. Just wanted to share real life incidence that happened which showed the real face of all these digital craps.

I just found lynx india also sells this:
Belkin 8-Out Surge Protector W/TEL/AV/NET Gold Series ? Lynx - The Audio , Electronics And Computer Online Store In India

Belkin is the best, 'reasonably priced' available bet (IMHO)!

Is this gold series belkin surge protector good enough to protect a Subwoofer, AVR & 5.0 Speakers...?

Thanks

 

[borg]

"High voltage rupture disk"-- the technial name is Varistor- MOV
Varistor - Wikipedia, the free encyclopedia

The reason for stabilisers being slow is not just the relays, (relays that operate under 5ms is quite there) but the processing. The sensing circuit that operate the relay need to monitor the input ac waveform and need to be sensitive for sudden changes and at the same time should have sufficient hysterisis to prevent relay chattering. The design strategy is at fault here, most of the stabiliser designs is too slow to react and is not really equipped for this type of situations, They are just for slow varying inputs and also only within a certain specified range unfortunately realworld conditions are far from it

 

[hifiashok]

Is this gold series belkin surge protector good enough to protect a Subwoofer, AVR & 5.0 Speakers...?

Thanks

we need to separate this into two parts, viz., surge-protection and power-conditioning. for surge-protection the Belkin is a good option. do check on the rating on the specific product you choose so the multiple products that you need to handle are supported.

 

[rana_kirti]

we need to separate this into two parts, viz., surge-protection and power-conditioning. for surge-protection the Belkin is a good option. do check on the rating on the specific product you choose so the multiple products that you need to handle are supported.

So is this a correct path....?

Belkin Gold Series ( for surge protection ) + Servo Stabalizer ( for power conditioning )

Would this provide complete protection ?

Thanks

 

[hifiashok]

So is this a correct path....?

Belkin Gold Series ( for surge protection ) + Servo Stabalizer ( for power conditioning )

Would this provide complete protection ?

Thanks

Yes, this a reasonable option. I use a CVT with a Belkin, considered a better option over the servo one. Of course, there are better options. However, pl note, there are no absolutes.

 

[rana_kirti]

ashok thanks buddy...

i spoke to vertex at bangalore but they dont supply thier audio grade servo stabalizer to delhi.

1. So can you or anyone suggest a excellent brand of servo stabalizer available in delhi ?

 

[alsekar]

I am in the planning phase of building a HT(refer my thread: http://www.hifivision.com/my-audio-video-setup/14495-my-journey-building-home-theatre-new-) and this thread has opened my eyes to an important aspect in building an HT. Thanks to all the contributors to this thread.
Regards

 

[digitalv]

ashok thanks buddy...

i spoke to vertex at bangalore but they dont supply thier audio grade servo stabalizer to delhi.

What exactly is an Audio Grade Servo Stabilizer?

 

[hifiashok]

ashok thanks buddy...

i spoke to vertex at bangalore but they dont supply thier audio grade servo stabalizer to delhi.

1. So can you or anyone suggest a excellent brand of servo stabalizer available in delhi ?

well, i would still not recommend a servo (over a CVT) for this specific application. i use a Bhurji CVT, considered the best there is (in India, of course). conceptually, the CVT is an isolation transformer and works on a saturated core principle. a CVT can handle input spikes upto 1500V (tho', not lightning strikes) and the o/p will not vary more than 1% (from 230V). however, if you must look at a servo, go for AE (Automatic Electric), a Pune based company. their variac and auto transformer are separate. if that is not an option, go for Logicstat, Delhi. they use both on the same, to cut costs. btw, servos are also available with isolation transformers, but, i would still recommend a CVT.

 

[suri]

i would still recommend a CVT.[/COLOR]

but,

CVT has a resonant core?

Quote - "An alternative method is the use of a type of saturating transformer called a ferroresonant transformer or constant-voltage transformer. These transformers use a tank circuit composed of a high-voltage resonant winding and a capacitor to produce a nearly constant average output with a varying input. The ferroresonant approach is attractive due to its lack of active components, relying on the square loop saturation characteristics of the tank circuit to absorb variations in average input voltage. Older designs of ferroresonant transformers had an output with high harmonic content, leading to a distorted output waveform. Modern devices are used to construct a perfect sine wave. The ferroresonant action is a flux limiter rather than a voltage regulator, but with a fixed supply frequency it can maintain an almost constant average output voltage even as the input voltage varies widely.

The ferroresonant transformers, which are also known as Constant Voltage Transformers (CVTs) or ferros, are also good surge suppressors, as they provide high isolation and inherent short-circuit protection.

A ferroresonant transformer can operate with an input voltage range 40% or more of the nominal voltage.

Output power factor remains in the range of 0.96 or higher from half to full load.

Because it regenerates an output voltage waveform, output distortion, which is typically less than 4%, is independent of any input voltage distortion, including notching.

Efficiency at full load is typically in the range of 89% to 93%. However, at low loads, efficiency can drop below 60% and no load losses can be as high as 20%. The current-limiting capability also becomes a handicap when a CVT is used in an application with moderate to high inrush current like motors, transformers or magnets. In this case, the CVT has to be sized to accommodate the peak current, thus forcing it to run at low loads and poor efficiency.

Minimum maintenance is required. Transformers and capacitors can be very reliable. Some units have included redundant capacitors to allow several capacitors to fail between inspections without any noticeable effect on the device's performance.

Output voltage varies about 1.2% for every 1% change in supply frequency. For example, a 2-Hz change in generator frequency, which is very large, results in an output voltage change of only 4%, which has little effect for most loads.

It accepts 100% single-phase switch-mode power supply loading without any requirement for derating, including all neutral components.

Input current distortion remains less than 8% THD even when supplying nonlinear loads with more than 100% current THD.

Drawbacks of CVTs (constant voltage transformers) are their larger size, audible humming sound, and high heat generation." Unquote. (from wikileaks)

 

[hifiashok]

suriji, could not understand the 'but'. r u saying the CVT option is not a good suggestion?

yes, a CVT does not run efficient. generates a lot of waste heat. has a loud hum (so my earlier suggestion of keeping it far away from the audible area). but, from a power conditioning (and to an extent surge protection) perspective, there aren't many that come close.

 

[captrajesh]

Very informative thread. But IIRC, I read in some thread in our forum that CVT is not conducive for sound systems and Servo stablizers are better suited for that application. Do not remember the reasons enumerated though

 

[Kevian]

Based on the posts in this thread I find MOVs mentioned by Sridhar as most economic and effective way to protect electronic equipment than Servos, Spikes etc.....

So I googled on this of how to install and where to procure fro...found this link .... after seeing it I realized its out of my domain to comprehend...can anyone help?

btw I got RCD switches installed of 19 amps {I think}....in a box next to electric meter....the question is where do I install these MOVs and how?

Few pictures of the installed MOV setup would be of more help...Sridharji...are you listening?

 

[captrajesh]

Hi Venkus

Your link doesn't work.