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[Geoff Doane]

Here's the link to the Liebert series I was talking about:

http://www.liebert.com/dynamic/displayproduct.asp?id=1013&am p;cycles=60Hz

The configuration software needs to run on a PC, but it only needs to be done once, so you can probably borrow somebody's laptop for that.  You ought to have a UPS anyway if your rig includes a computer, and this is one way to get all your power coming from one source and isolated from any junk that might be out there.

Geoff

[E.P.]

Thanks, Geoff! I'll look into those.

I'm thinking one of those and a SurgeX will do the trick, although I maybe going to far there.

[John Monforte]

I have been reading this all along and I think I can chip in here.

I have been called in to fix noises and buzzes in studios and high-end audiophile stereo systems for 30 years now. In almost every instance, the causes were from methods that "improve" standard wiring practices in the interest of better sound (clipping power cord grounds, fancy Faraday shields, bizarre technical grounds leading to unusual places, etc.) Without exception, removing this "better science" has fixed problems.

I'm not saying 'anything but standard is bad', but gear has been designed with standard power wiring in mind and it works. Power supplies in gear have regulators in them that isolate gear from dippy, spiky and fuzzy utility power.

I have found a piece of gear or two that should not have been built the way it was and caused some problems, but that is the exception.

Spike protection will help if lightning hits you, but it will not do anything in normal day-to-day operation.

If you have a problem, get out the test gear to find and remove it. If you are looking for ways to get better sound, I'd look at the audio gear itself, not its power source.

[E.P.]

I think what you are saying, John, is pretty similar to what Keith has been saying. Now, I know very little about this, but I'm inclined to say I agree with you - don't get fancy, get the basic wiring right. I don't expect my gear to sound magically better, I just want to be protected from surges, and not have the problems that the Furman I used gave me.

However, I know so little that I might no know if what I'm thinking is too tricky.

Would a SurgeX, a good USP like the Liebert, replace the wall plugs with good quality plugs, and then plug everything in with MOV-less plug strips be sticking with the basics, with some protection?

That's what I'm thinking now.

But maybe you guys are saying why mess with the SurgeX or the UPS?

[Socrates]

Geoff Doane wrote on Tue, 23 January 2007 16:27

Socrates wrote on Sun, 21 January 2007 22:59 Bought all 6 500 kva units they had (heavy toroid with capacitors), and the jewel in the crown, a 1000kva tripplite that has soft-start circuitry so it doesn't blow a fuze when you turn it on. The small units I gave to family members for their systems, and have a few on the shelf.   Are you sure these are 500 kVA units, and not just 500 VA?  500 kVA would probably weigh as much as a car.... Geoff

Sloppy thinking...They are half and one kva as you suggest.

To answer Gil1, I think a surgex is important to protect your equipment against transients.  It is insurance and will pay for itself if it mitigates a large transient. Whether one needs some sort of power conditioning is another matter, and I agree with those who suggest a power conditioner may not be required.  I have mine mostly because I got a good one for $40!

The MOVs are moist-pro for a few reasons.

1) When they do their job they get a little more fried with each transient. Once totally fried, they are electrically inert.  So, you don't really know when your protection goes away.

2)  I can't remember the rest of the reasons.

Also, in a power strip, and some furman models, are the inductors and capacitors large enough to clean up lower frequence noise?  If they are teeny-tiny, all you have is an rf filter. I think the one rack space units are just a socket breakout with a few movs and just enough inductors and caps to be able to claim noise filtering without being sued by the ftc.

Its been a couple of years since I researched this and did my setup, but my impression was that the furman brand was quite a bit more expensive for what it does than if you look into regular electronic equipment suppliers.

I got a surgex brand gadget for transient suppression. I think it uses capacitors and is not consumed or worn out when it supresses a transient--between $100 and $150 and I suppose its good for 15 amps or so.  Also, it is designed not to shunt the transient to ground as that just makes the ground hot due to its inherent resistance and inductance.

I don't know what 'power conditioning' really means, but what I have is basically a giant low pass filter which reduces noise on the line and creates a ground that is between the two legs of the ac line rather than being tied to one of the ac legs as 110 volt lines are wired. Since I have absolutely no problems with hum as long as everything is plugged into the same buss, its either working or its unnecessary. The noise filter is a different box than the transient suppressor--they do entirely different tasks.

As far as taking power off two legs of a three phase system, I have always been puzzled by this.  Near as I can tell, any two legs are going to be 120 degrees out of phase with each other rather than the 180 degrees of a regular two wire system. So, does that make the RMS voltage a bit less than it would normally be? I guess as long as the power supply is getting all it needs...

In response to a recent question, I will re-iterate that I ran a separate cable from the distribution box (the circuit breaker box) up to the bedroom studio. First of all, I was having problems with the lights going dim or blowing a breaker due to the heavy current surge of some of my goodies on power-up. The bedroom wiring is designed for lights esentially and nothing else. Also, the vacuum cleaner will occasionally pop the breaker and I hate to have my computer do hard crashes.

To scale this concept to a larger installation, I think the important thing is that all 120 volt stuff is coming off the same side of the 220 volt feed. Otherwise, there can be a 220 volt difference between the hot side of two pieces of gear, and as good as the gear might be, there can be noticeable hum--this happened to me.

At this point, my system is completely and absolutely silent and free of 60 cycle hum, so I am satisfied. As I read this I was thinking how nice it was to have a hum-free setup for a couple of years since there was a time when I seemed to be dinking around with it all the time.

One caveat: If you use balanced power, and plug in a guitar amp that is essentially a two-wire approach where the chassis is tied to the 'neutral' side of the ac line--there is a big problem.  I think older Fenders and Marshalls would do this with a cap and a switch where you were esentially putting the chassis to whichever side of the ac line gave less noise. With balanced power, the ground is in fact 60 volts away from the hots, and if you short them together you have a problem.

The cure is to ensure that the amp has a three wire power cord where the ac hot and neutral go only to the power transformer and the ground goes to the chassis.

[Socrates]

John Monforte wrote on Tue, 23 January 2007 19:57

...Power supplies in gear have regulators in them that isolate gear from dippy, spiky and fuzzy utility power...

I used to take this position quite strongly myself, but I was exposed to some situations where the noize was getting through.  My  thought was that the high frequency interference does not play by the rules and leaps adjacent wires that have tiny capacitive coupling and so on.

If I take your approach to be getting the fundamentals 100% correct (wiring, grounding) and see if there is still a problem--I agree. And to have the wiring wrong and trying to cure it with yet more fixes is futile and maybe dangerous.

Better wall sockets might grip the plugs better if you have worn-out ones that are old and loose, but I normally would not bother otherwise.  Did the hospital plugs thing in my 'audiophile' phase, but can't say it made any difference.

[ssltech]

Socrates wrote on Tue, 23 January 2007 21:58

John Monforte wrote on Tue, 23 January 2007 19:57 ...Power supplies in gear have regulators in them that isolate gear from dippy, spiky and fuzzy utility power... I used to take this position quite strongly myself, but I was exposed to some situations where the noize was getting through.  My  thought was that the high frequency interference does not play by the rules and leaps adjacent wires that have tiny capacitive coupling and so on.

Regulators have to 'respond' to a change, and they have a reaction characteristic which is usually pretty slewed. For that reason they do tend to let HF noise through.

And Toroidal power transformers frequently have strong capacitive coupling between the primary and secondary, because the two are wound right on top of one another.

Put these two together, and you can DEFINATELY see how HF noise can and often does find a way through onto power rails. Now, consider the number of high-frequency switching power units out there, and it becomes plausible that there could be HF noise to find it's way through onto your DC power lines.

So maybe I appear to have argued against myself there, I'm not sure... -All switching power supplies seem to have L/C filters on their AC power input connections though, to prevent this sort of muck from getting out.

RF noise on the lines coming into boxes can be treated though. What John M. says is an excellent approach, in my view.

However, I certinly have had people proselytize to me about how their new power conditioner "got rid of the 60Hz noise"...   -That's really a neat trick! -Without that "noise", most conventional power supplies will cease to function!

The 'Hospital power sockets' (hey, I know it's very pedantic of me, but can we PLEASE stop calling them "plugs"? -They really AREN'T plugs, they're SOCKETS, ferchrissake!!! ) won't do a thing for you if you just swap them out and don't change the ground wiring... you HAVE to add a single, insulated ground return to the central point at the fusebox.

In the UK -interestingly- this approach is VERY uncommon. The British power wiring regulations require what's called a "ring main", where power is wired through three 'loops' around a room: a live ring', a neutral 'ring' and a ground 'ring'. The idea is that if you use 20Amp wire, every socket on that ring will have 2 x 20 amp paths in parallel. This distributes the load and reduces current-driven dips. -Certainly, just about every house in the USA that I've ever been in, the lights dim when you turn on a hair-drier. I don't recall ever noticing the effect in any UK home which was wired in the last 30 years or so...

So we have more constant power in the UK. -Yay! -But I can also tell you that 50-Hertz induced hum just doesn't respond the same way to the same rack wiring approaches. If two things are grounded to different sockets in the UK, the loop areas in play suddenly get very large, and the induced ground currents tend to modulate the ground potential, or cause a tiny current to flow up and/or down the ground conductor in your power cable... YIKES!

So yet again I have realised that I should -in the interests of more comprehensive posts- have prefaced my posts earlier with "In the USA..." -But I hope you get the picture.

Here's a simple thought we can hopefully all nod our heads to:

If power grounds all star back to a nice, quiet (unmodulated) ground point, and care is taken so that loops are not set up which can induce current to flow along the cables, (I mean... they're running RIGHT alongside some 50Hz/60Hz cable with BIG AC voltages on them, and sometimes a sizeable current flowing also!) then power ground should be quiet.

Quiet power ground can certainly work as well as a good technical ground, but sometimes you can't get power ground very quiet (because you're next door to a metal-lamp-post fabrication facility with a hundred arc-welders going all hours, dumping massive currents into power ground, and modulating yours no matter WHAT you do!) then a technical ground may become VERY important in your future.

See... This is why Art Kelm over at "Ground One" gets a lot of work. The solution varies with the problem, the problem varies with the location. There's not a simple rule, there's several rules, there's experience, there's testing and there's VERY often a combined-approach solution to most problems.

-Put it all together and you've got a consultancy.

-That'll be twenty-five dollars, please.

-I'll take payment in GB

[Socrates]

Hospital sockets? Wow! I need to get some, I have been using hospital plugs in regular sockets and wondering why its only a 50% improvement.

Oh, and also, I read a good book on solid state voltage regulators once, and they have a 'seeking' voltage variance in the rf regions as the device is constantly either reducing or increasing voltage withing its narrow tolerance range while responding with a tiny delay to the voltage sensor. This noize can be de-coupled with a capacitor.

The UK ring thing is interesting--isn't that three-phase power?  The thing the UK has is 220 volts, so they draw half as much current for a given load.  Might account for the stiffness of their voltages. But, yes, my house was built in 1959, long before anybody started thinking about 1500 watt blow-dryers. Given what I am reading about london housing prices, the power ought to be top-notch indeed!

OTOH, is there a deal in the UK where the plugs and sockets are not standardized so they buy stuff with wires hanging out and have to install the plugs themselves?

I know I went on quite a while in my other post so it might have gotten buried, but I am still wondering about this notion of using two legs of a three-phase power supply. Specifically, does it work properly with the voltages being only 120 degrees out of phase with each other rather than 180?

PS. The other day I was working on the plumbing and noticed that the cold water pipes sparked a bit when I disconnected them.  So, I have some kind of juice going to ground on a regular basis.  I suppose I should have gotten the meter out and tried to find the offender, but was too busy sweating the pipes to bother.

[ssltech]

Quote:

Hospital sockets? Wow! I need to get some, I have been using hospital plugs in regular sockets and wondering why its only a 50% improvement.

Medical-grade plugs are rated pretty well, but if you're only drawing a trickle, there's no compelling reason to get them.

In the UK, -since we're going cross-border here- the power plugs all by law have replaceable fuses in them, which must not exceed 13 amps. The metal is brass, it's solid and you CANNOT bend it. each pin is a block of brass, 'bout ¼" thick... There is ONE legal exception to the fused-plug rule... only one. -It's in hospitals also -as it happens- and it's for X-ray machines with mechanical, non-sprung shutters over the radioactive source. They are allowed to use unfused power plugs, but the plugs MUST be coloured bright red, to differentiate them as potentially 'unsafe' (unfused).

Quote:

The UK ring thing is interesting--isn't that three-phase power?

No, that's something differnt. 240V single-phase is sent around your room by a ring main.

Power over there is nominally 240V (typically 247V). Most houses get a single one of the three phases. Just as in the US, (where 3-phase power is 3x 120V, and wiring between any two lives gives 208V) here in the USA we get two poles of what is in reality a single 'phase', insofar as its timing is unshifted. The terminology is confusing, and people argue for and against the calling of the inverted leg a "phase", but essentially, power is sent to the pole-pigs as 3-phase. The pole-pigs just sniff one phase leg at a time into any given house, then polarity-invert that phase... That's how I prefer to think of it. Wiring between lives in the UK produces 415V, basically double what you get here. Cross-sectional area of copper wire per ampere of current permitted to be drawn is also more conservatively rated over there, which also helps limit voltage sag. Also, wire-nuts are illegal in Britain (ans very possible all of Europe). All connections have to be brass screws into brass blocks. Much more expensive, much more labour intensive, but rather more reliable. -This aspect of the USA electrical codes I can only assume has been driven by the economic pressre to get things working quickly, cheaply and easily as opposed to safely and reliably.

Quote:

is there a deal in the UK where the plugs and sockets are not standardized so they buy stuff with wires hanging out and have to install the plugs themselves?

Plugs are ABSOLUTELY standard. However, whenever it was, -about 30-40 years ago maybe- when the present 13-amp electrical system was brought out, there was an older system which allowed up to 5 amps per socket. It used round pins as opposed to the newer rectangular-section pins. Thus people were allowed to install their own plugs to be sure that it would work with their home setup, instead of having to rewire their entire house just to plug in a new toaster... and then buy all new appliances to fit the new sockets etc.

That's no longer the case really, but do be aware that stuff in Europe is also 240V, and they have several different electrical connections. Therefore plenty of gear made and sold in Europe will have bare wires and the user can install their own plugs. The manufacturers would otherwise have to make a dozen different versions of a toaster for example...

Quote:

I know I went on quite a while in my other post so it might have gotten buried, but I am still wondering about this notion of using two legs of a three-phase power supply. Specifically, does it work properly with the voltages being only 120 degrees out of phase with each other rather than 180?

I think I just touched on it. In the US and A, you get 208V between ANY 2 phases of three. Any single phase leg to neutral gets you 120V. In the UK it's 240 and 415 respectively.

Because of this massive 415V between live legs, two power phases may NOT be used to feed power sockets in the same room, unless they're some B-I-G distance apart, because if you plugged in two guitar amps on to different phases, and both chassis went live (it happens, trust me!) then the two guitarists would have a HIGHLY pyrotechnic handshake!

Quote:

The other day I was working on the plumbing and noticed that the cold water pipes sparked a bit when I disconnected them.  So, I have some kind of juice going to ground on a regular basis.  I suppose I should have gotten the meter out and tried to find the offender, but was too busy sweating the pipes to bother.

Could be static if it's cold where you are... but you'd have to meter it. Remember, this is the time of year when doorhandles bite you, and women who start the gas pump and then go into their car (to retrieve their cellphone and call someone while the gas is pumping) get the shock of their life when their gas pump bursts into flames as they go to remove the nozzle...

Of course they blame the cellphone, instead of the static charge that they built up going in & out of the car to retrieve the blessed thing... and that's how another urban myth gets started!



Keith

[E.P.]

Well, I'm hanging on in this thread by my fingernails, but I guess that's how you learn.

What I'm wondering now is:

Is the only purpose of a UPS to give you time to shut down if there is a power outage? I know some people would say they protect from surges and noise, too, but then I'm hearing that they also turn your power into a square wave, and that's not good. So I'm confused.

Given that the only time my power drops so low that my computer shuts down is in a storm, and I can just not work in a storm, is the Liebert mentioned before a good idea or not?

Gil

[Socrates]

My prescription is one surgex and see how you feel in the morning.  I used to use a UPS on my computer, but when all was said and done it was too much hassle, so I just take my chances.

[rufus13]

[Andy Peters]

Gil1 wrote on Wed, 24 January 2007 15:16

Is the only purpose of a UPS to give you time to shut down if there is a power outage? I know some people would say they protect from surges and noise, too, but then I'm hearing that they also turn your power into a square wave, and that's not good. So I'm confused.

You're right; the main purpose of a UPS is to allow the equipment to ride through short (single-digit minutes) brown- and black-outs.

Computers don't like to be powered-off without proper shutdown.  The shutdown cleans up and closes the filesystems to ensure that no data are lost.  So a UPS that can tell your computer that it's got two minutes of battery time left is a good thing.

A UPS is good on digital gear, especially when it can save programs to EEPROM (or update its firmware).  You can "brick" digital stuff if power is interrupted during firmware updates.  Other than that, though, the main concern with digital stuff is that boot time is longer than basically instant-on analog.  

(Digital gear with "universal" switch-mode power supplies have the bonus feature of being able to deal with wide-range mains input voltages, so undervoltages may not be as problematic as with a linear regulator going out of regulation.)

Now, some UPSes also have surge protection on their mains inputs, and some don't.  RTFM.

Also, some UPSes have true sine-wave output and some have stepped approximations of a sine wave, so again, RTFM.  Hint: cheap UPSes won't have true sine-wave output.

-a

[James Perrett]

I just thought I'd update Keith's information about UK power - things have changed a little since you lived here...

ssltech wrote on Wed, 24 January 2007 21:18

Power over there is nominally 240V (typically 247V). Most houses get a single one of the three phases.

EU legislation is changing this - the voltage throughout Europe is now 230V +/- 10%. That's a fudge that means the UK's 240V and the rest of the continent's 220V supplies still fall within the permitted tolerance but eventually all supplies will be standardised at 230V.

ssltech wrote on Wed, 24 January 2007 21:18

Quote:  is there a deal in the UK where the plugs and sockets are not standardized so they buy stuff with wires hanging out and have to install the plugs themselves? Plugs are ABSOLUTELY standard. However, whenever it was, -about 30-40 years ago maybe- when the present 13-amp electrical system was brought out, there was an older system which allowed up to 5 amps per socket. It used round pins as opposed to the newer rectangular-section pins.

13A plugs are now fitted to everything you buy in the UK and the modern plugs are much less fragile than the older ones. In the old days there were all kinds of standards - 15A, 5A and 2A round 3 pin plugs, 5A and 2A 2 pin plugs and people would often plug their radios into the bayonet light sockets. You cold even buy Y adaptors for light sockets which allowed you to use your radio and still have light.

Cheers

James.

[ssltech]

James Perrett wrote

I just thought I'd update Keith's information about UK power - things have changed a little since you lived here... Quote: ...240V... EU legislation is changing this - the voltage throughout Europe is now 230V +/- 10%. That's a fudge that means the UK's 240V and the rest of the continent's 220V supplies still fall within the permitted tolerance but eventually all supplies will be standardised at 230V.

I wondered when that would all get fededalised. I used to play the occasional gig at "Fiddler's Ferry" power station in Cheshire. The power station was reasonably big -it had eight cooling stacks- and if the regular joke when bands set up was "you want us to crank it up a bit for you???"

James Perrett wrote

13A plugs are now fitted to everything you buy in the UK

Good. About time! -Much better than having a mypoic aunt electrocute themself!

James Perrett wrote

and the modern plugs are much less fragile than the older ones.

Again...VERY good. Moulded plugs have their advantages.

James Perrett wrote

In the old days there were all kinds of standards ...people would often plug their radios into the bayonet light sockets. You cold even buy Y adaptors for light sockets which allowed you to use your radio and still have light.

Pah! -Radios? -For wimps!

My mum used to plug the clothes iron into the light socket. -Think about how much current THAT was tugging down the flex!!!

Obviously these are things of the past, I hear you say. -And I was reminded of the iron-plugged-into-the-bayonet-light-bulb-socket only last week at lunchtime. -I went into the local subway to get a sandwich. They have wireless internet there as a 'magnet' for lunchtime diners, but no power outlets. -But they do have a pendant lamp in a diffused reflector shade above every table. This one chap had unscrewed the light bulb and plugged in his laptop power brick, via a screw-in adaptor. -I checked around for 'vacuum-cleaner-accessible' power outlets and found none in the dining area (this place was built ground-up about a year ago, so it's recent. -I found it fascinating that there were NO outlets in the dining area. The architects obviously thought that power-sucking by the dining public was going to become an issue.

Plus ca change, plus c'est de la meme chose!

Keith