Smooth Power

[wacki]

Hi,
Just wondering, if I was to build a house and I wanted to protect all of my sensitive computer equipment and expensive audio setup, what would be the best way to smooth out the power. My current home suffers from sour power and I'm sick of worrying about fluctuating voltages frying all of my equipment. Basically what would be the best way to smooth out the AC to your home. Cost isn't a major factor.

Also, am I correct in assuming transient suppressors don't really condition the power but only limit spikes?


The best solution I've found so far:
http://www.furmansound.com/consumer/ref/rvc-7w.htm

is there better/cheaper?

Basically computing and audio equipment power must be protected/smoothed out.

 

[Geniere]

The device in your link will not help as far as power fluctuations in fact it will worsen that condition because it uses a less efficient toroidal transformer. It cannot provide total isolation as it is stated. The toroidal wound transformer allows the primary windings to be separated from the secondary to reduce capacitive coupling, but some capacitance exists although much lower than with a conventional transformer. This device would be helpful in reducing voltage spikes of high amplitude and short duration, but so would a much less costly filter with a surge protector. It would be far down on my list of choices because of its expense. Whatever device you may use, requires testing periodically to determine if it?s doing its job.

 

[Pudgygiant]

A line conditioner + small UPS would probably work for this. Most line conditioners (the good ones anyway) come with a built-in surge protector. If you really wanna spend dough you can get a UPS with built-in conditioning and surge protection... the one catch would be you couldn't plug your laser printer into it (assuming you have one).

 

[wacki]

Originally posted by: Geniere
The device in your link will not help as far as power fluctuations in fact it will worsen that condition because it uses a less efficient toroidal transformer. It cannot provide total isolation as it is stated. The toroidal wound transformer allows the primary windings to be separated from the secondary to reduce capacitive coupling, but some capacitance exists although much lower than with a conventional transformer. This device would be helpful in reducing voltage spikes of high amplitude and short duration, but so would a much less costly filter with a surge protector. It would be far down on my list of choices because of its expense. Whatever device you may use, requires testing periodically to determine if it?s doing its job.

I didn't know transformers were subject to capacitive coupling. What recommendations do you have for products that could smooth out the ripples in the household current for computing and audo visual equipment.

Also, do you know of any good books that I could read about the subject? And what should I look for (spec wise) when buying a filter/conditioner.

 

[Geniere]

A capacitor is formed when two conductors are separated by an insulator, even air. The greater the surface area, the greater the capacitance. The wires in the transformer act as a capacitor due to their proximity. Some call it ?stray capacitance?. This also provides for good inductive coupling, which is desirable in a transformer while the capacitance coupling might be described as undesirable for some applications. A toroidal wound transformer can separate the secondary windings from the primary windings thereby reducing capacitive coupling but, as well, the inductive coupling and thereby is less efficient.

More when I get some time, probably this evening.

 

[wacki]

very informative, looking forward to hearing from you.

 

[Geniere]

Hi Wacki:

I?m not quite sure what you mean by ?smooth out the ripples in the household current?, but it?s probably meant to refer to voltage fluctuations due to the power company or electrical ?noise? on the wire such as produced with an electric drill due to commutator sparking. I don?t see the possibility of one of your branch circuits being overloaded and decrease the voltage to a point where you would notice it, as the circuit breaker should trip.

Perhaps PowerEngineeer might want to comment on allowable voltage fluctuations

I?d start with the basics. The electrical code (I think) allows a maximum of seven duplex electrical outlets on any given circuit breaker. Assuming a 15-amp breaker, that allows for powering about 1500 to 1800 watt total load and up to about 2400 watts for a 20-amp breaker. A PC, light bulb, and a music amp are loads, which you would add to get your total load. I would avoid using more than 75% of available power. I would not have the audiovisual components and the PC on the same branch circuit unless it?s a 20-amp circuit. Determine what devices are plugged into the branch circuit and consider if it could produce electrical noise. A florescent lamp could generate a lot of noise. Even an incandescent lamp could generate noise if its socket is pitted or the bulb itself is pitted. Anything with a motor should go bye-bye.

REMBER SAFETY FIRST!

Visit your circuit breaker panel and visually inspect it for corrosion, and if you know what you?re doing tighten all screw terminals with particular emphasis on the neutral and groundING wire buss (same buss). You should find a bare, large diameter copper wire exiting the breaker panel and going to a buried grounding rod. It may be hard to trace but if you see the wire in your panel, you?re probably ok.

REMBER SAFETY FIRST!

Replace any duplex outlet on the circuit with a quality 20 amp outlet (even if it?s on a 15 amp circuit), and in the process correct any wiring errors. Only use outlets that have a screw for securing the wire, not the push in connection type. The groundING wire (green or bare copper) is connected to the green screw terminal. The neutral or groundED conductor (white) is connected to the nickel-plated screw terminal. The remaining ?hot? wire (any color but green or white) is connected to the brass colored screw terminal.

Buy a digital voltmeter with a max/min feature, which you can plug into an outlet for a few days to find the lowest and highest voltages. Without the max/min feature, you?ll have to measure a few times each suspect hour and hopefully when a problem occurs. I would not be concerned with readings within 107vac to 126vac, unless you have a low quality PC power supply. Since I drop my expensive Fluke meter so often, I decided to buy a cheapie digital meter from ?Harbor Freight? (google it) for $3.99 a pop. For 4 bucks it is amazingly decent.

If you?ve survived and having done all above, problems may still exist but at least there is now a firm foundation to build on. Even if problems do not exist, as you implied, it?s nice to have a comfort factor and an insurance policy by using additional protection.

If money is no object, you are on the right track with the Furman device. My objection to it is the several citations of ?totally?. This is enough to deter me from buying for the same reason I avoid buying a musical amplifier based on ?peak music power? or a shop vac based on ?peak horse power?. The device could be quite good but it sounds like a marketing ploy. Also it does not seem to offer anything to maintain voltage stability.

I?ve only specified similar devices to protect my company?s products (multi-million dollar medical equipment) from two manufacturers, one of which was merged with the other. The survivor is Oneac Corporation (pronounced oh-nee-ack). They have a web site. I know their products to be quite good but other manufacturers products may be as good or better. Call or E-mail them for advice and pricing. They offer a do-all device.

If it is too costly, we can get into other options.

As far as a good book, I seem to recall one pointed toward the layperson but can?t remember the title. It may have been titled ?Power and Grounding?.

 

[Howard]

If cost isn't a major factor use a battery storage system as a buffer.

 

[Abzstrak]

Originally posted by: Howard
If cost isn't a major factor use a battery storage system as a buffer.

Agreed, APC makes 10kW-200kW systems... this is defintely the best way