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I’d like to add a separate circuit for a pc. Is an isolated ground necessary or desirable? Are spec or hospital grade outlets worth the extra money? Metal box or plastic? Any recomendations for surface mount wiring ? …..Don’t want to fish thru’ blown in celluouse. Many Thanks.
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hey j - I don't know squat about your wiring but that blown in cellulose is some sweet insulation, isn't it? - yb
*Be sure to use 10 gauge oxygen-free copper wire....Ho, ho, just kidding..I got on an audiophile jag there for a moment. Guess I'm trying to say that, from a common sense perspective, a PC is no different from any other electrical device that has a power supply and some sensitive microcircuits that can get fried by surges. In other words, the "purity" or "quality" of the current entering the PC doesn't mean anything to it, so most of your questions are answered with, "It don't matter." Now I suppose some "computerphile" can pop up with some stuff about how it do matter, but I doubt it does on any significant scale. Surge protection does matter. Having a separate circuit will eliminate voltage spikes from other appliances on the circuit, so it doesn't really matter where the surge suppressor is located, though the circuit panel types generally cost more than those at the outlet. Every home center I've been to has had a surface wiring system of some sort in its electrical section. They all are about equally ugly, too.
*I'm a bit of a 'computerphile' and agree with Barry. We don't put any special isolated wiring into our instalations. Just think about surge protection, especially if you have poor power reliablity in your area. If it's a new house you may also want to think about a bit of network cabling linking possible computer locations in the house (bedrooms, study, utility room) or at least put some conduit with pull strings in. Cheers,Scott.
*Dear Computerphiles,Would you share specific cable type and grade specifications for residential networking and home office use? Phone, co-axial, etc.
*Scott,What's your take on Intel's new home network device that uses the phone line to link separate computers? A similar concept with using the AC lines for TV reception, intercoms, etc. has huge drawbacks. Is this the same? QED's question is also cogent, as it seems that any built-in cabling becomes obsolete fairly quickly. What if I put in the latest twisted pair or fiber optics only to have the cable company's coax become the standard?
*Hi Barry.I don't know anything about Intel's latest. I'll have to read up on it.Regarding cable types... Catagory 5 vs. Coax. I'd start with 1" conduit with pull string. Put whatever cable you use today or, if it makes you feel better put both types in at the outset. Just make sure you leave a pull string in. If the runs are long or convoluted, be sure to put pull boxes in the middle of runs so that you can pull the cable a bit at a time. Hide the pull boxes in closets or behind doors and cover them with something nice to minimize unsightliness. Category 5 cable is particularly suceptible to abusive treatment.I would run each cable back to the utility/mechanical room of the house and use this as a wiring closet. If you have multiple computers, printers, or other devices then this is where your hub equipment will sit. This room is also a good point of entry for your phone and cable service.Cheers,Scott.
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Cellulose may be fine in many applications but in this case I think it was a mistake. The house was built in the 1880's. Since the stuff was blown in, it seems as tho' the house is self destructing ..... moisture problems. Going to pull some clapboards this summer (if they don't fall off first) and check it out. Feel bad about it, it's the folks place.
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IMHO, don't bother with a separate branch circuit for the PC. Computer equipment actually uses very little power.
The supplied AC does have to be clean and stable, though. But rather than going to the trouble and expense of adding a branch circuit, I think you're MUCH better off just using an existing outlet and buying an UPS (Uninterruptable Pwer Supply). These have gotten pretty cheap lately ($99 for the ones with smaller batteries), and are the ultimate in cleaning up the AC.
I view "surge suppressors" with a great deal of skepticism. There are no standards for them, and many if not most of them offer only the minimum of protection. And none of them will isolate your PC from brownouts and voltage dips (say, caused when the furance or air conditioner fan kicks in).
As for networking, I'd run Cat5 and Coax. Cat5 twisted pair is good for everything from telephones to Gigabit Ethernet. Coax's for TV. I can't see any residential datacomm need for fiber, but it might be used for routing Dolby Digital Surround Sound.
Also, don't pull Cat5 through too long a run. If it stretches too much, it'll no longer work like Cat5 and won't work too well for high speed data (100Mbit and up).
--BarryO (ccomputer engineer "day job")
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The service is fairly recent but the wiring is ancient- no grounded outlets ......been using an adapter.
*Spec. grade recepitcals are definatly worth the money, they are only about $2 each, hospital grade is excessive (unless you are building a hospital), I wouldn't use the 3 for a dollar recepticals for anything. If you like the industrial look, you could suface mount EMT.Jay
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Some of this was covered on an old thread, for additional info try < Obsolete Link > this link.
*J. you've got potential problems. Choose your approach, either from the inside or outside, but the walls must open. If timberframed, check for soundness, watch for powderpost beetle damage. Conventional wisdom is they infest new, moist wood only. Add "moist" back into old wood, and shazzam...bugs. Seen it last year in a circa 1830-1850 house.Seemed old and dry at first. Had cells blown in with no: vapor barrier/house wrap/tarpaper. Sorry 'bout the bummer, dude.
*Computers don't care if they're connected to ground (i.e., their operation isn't affected). Although for safety reasons, you should see to it that they are grounded, somehow, through the 3rd prong: it's very unlikely, but a short in the power supply could make the chassis "hot" otherwise.
*If you are using a modem, you REALLY need a ground. I have seen a number of computers blown thru the phone line. Even a laptop running on its own power should have its phone connection run thru a grounded spike protector.
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UPS's like the APC BackUp 650 Pro have a place for the phone line ..... but I am wondering, do most ups's use a wire circuit's ground for protection, a fusible link, or both? Thanks for all the previous posts ..... really helpful.
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They use the circuit ground.
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JC, et al;
Isolated ground circuits are usually needed only if you have a large amount of rotating machinery on the same service. They are the sources of "dirty power". 3 phase air handlers are the worst (best?) sources
The chassis ground is an important feature. It is there for added ESDS protection. You should run a ground line for the computer circuit.
I feel spec grade receptacles should be mandatory in kitchens, bathrooms, & hallways. These outlets tend to receive high current appliances or frequent usage. The residential grade are fine for lamps or low wattage appliance you plug in and leave plugged in.
Surge devices can save your equipment. Make sure to have them on your power, cable input, & telephone. Look for UL® 1449. Also, if you a lightning arrestor rated at 600 volts & a surge arrestor rated at 300 volts, guess which one will take the hit?
Cheers;
JE
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Ditto.
Ultimate protection can be approached with a UPS system. This will protect against low voltage/brownouts.
I also suggest an surge/isolation device on phone lines (either modem or phones) especially with electronic phones and in rural areas.
*J, George,I hate to deviate too far into the perilous topic of cells here, but I would like to know more about the specific instances you've cited with moisture problems.Were these dense-packed intallations or conventionally filled? What is the construction of the cellar floors/crawlspaces? Dirt? Concrete? Any water problems in the cellar?J, how is the self-destruction manifesting itself?Thanks,Steve
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Steve, Foundation is stacked granite, there was a water problem ..... installed a drain from cellar which exits the side of a hill. The celluose was conventionally installed ....it was a state/fed program ...wasn't here when they did it. Dirt for thr cellar floor. The house was sound when they bought it 27 years ago but it really seems to have deteriorated since the stuff was blown in early 80's.It seems to have retained moisture and my suspision is that it is a combination of things, exterior moisture penetrarating the clapboards, interior moisture from cellar and unvented bath and damp cellar, and no vapor retarder. Any thoughts you might have would be greatly appreciated. Thanks
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J,
Sounds like a major part of the problem is the cellar. A dirt floor, even when dry to the touch, can be releasing a lot of moisture into the house. Any insulation installed with no effective air-diffusion retarder would have started the process of holding moisture in the walls.
Try putting a two-foot square patch of plastic on the floor and weight it around the perimeter. Leave it there for a few days. If there is moisture under the plastic, then you have too much moisture coming out of the celler floor.
A layer of heavy poly or better yet, cross-laminated poly (sold at masonry supply locations) taped at the seams and covered with sand or stone to keep it in continuous contact with the floor should cut the moisture in the house quite a bit.
But, and here's the rub, if the water in the cellar is running in through the walls, it'll pool up on top of the plastic, so you have to cure the infiltration first. What's the gutter situation? You could also pour a concrete floor sloped to a drain (again, using cross-laminated poly under the concrete).
My understanding of cellulose is that if it is blown to a density of 3-3.5 lbs/cu. ft. it will act as its own vapor barrier, but blown looser than that it needs a seperate vapor barrier. What are your inside wall surfaces? Plaster?
Steve
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Steve, the walls are plaster and I'm not sure about the density of the celluose. There's some poly in the cellar now. It(the cellar) is dry during the summer but springtime it is wet. I tend to think the celluose turned the existing situation into a real problem. As drafty as the house was, any moisture in interior wall cavities didn't stay there for long.I think the celluose retained the moisture. I won't know how bad it is till I tear into it, but I get the feeling it's too far gone to repair. Many thanks for the posts.
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jj,
Sorry to hear that. If you want to be able to keep the plaster and still insulate, you are going to have to get the moisture dynamics of the house cured, as any insulation will cause the same problems if the walls are being fueled with dampness.
Let me know what you see when you open the walls.
Steve
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Wondered how effective are those vapor retarding paints, if at all? Glidden used to have one called Insulaid.
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J,
I don't know specifically about the specialty paints, but any painted wall is a pretty good "vapor" barrier. The problem is that the moisture gets into the walls so many other ways than via diffusion through the surface. Most moisture is carried into the walls via air movement, so an effective air barrier is what is really needed, in addition to keeping the RH below 60 percent or so.
In a balloon-framed house the wall framing is a natural flue running straight from the wet cellar to the attic, usually fairly uninterrupted. Low density cellulose or fiberglass will not stop the wet air from flowing from the damp cellar through he wall cavities and unloading the moisture along the way. You need to physically stop air movement into and through the wall cavity. Bringing cells up about 3-3.5 lbs/cubic ft. Will do this. But if you still have very high interior moisture levels, you will still develop moisture problems.
You really have to get the moisture problem under control if you want to insulate effectively and still keep the house healthy.
Poly on the dirt is not effective unless it is brought into solid contact with the dirt by covering it with sand or stone (or concrete).
Steve
*On surge arrestors, i would suppose both would take the hit as any surge will exceed both thresholds. Get arrestors with a "ready" LED -- the technology used in some of them (MOV?) wears out with each surge that is clamped to ground. I put in an Intermatic surge suppressor at the panel and have one of the "insured" power strips -- that assure they'll pay for damaged equip. Insurance may be the ultimate protection.The only way i'll know if any of this works is if the neighbors get zapped and I don't.Spec outlets are absolutely worth the money for anything that draws more than an amp or is changed more than occasionally, I think. Don't use the spring-loaded backwire option on the 30¢ jobs.
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I'd like to add a separate circuit for a pc. Is an isolated ground necessary or desirable? Are spec or hospital grade outlets worth the extra money? Metal box or plastic? Any recomendations for surface mount wiring ? .....Don't want to fish thru' blown in celluouse. Many Thanks.