PinkyMacGodess
Suspended
Usually they don't. Heck, some places aren't even effectively grounded. It depends on the inspectors, and the maintenance people.
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Which power strip do you recommend? Is IKEA's OK?
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Usually they don't. Heck, some places aren't even effectively grounded. It depends on the inspectors, and the maintenance people.
Those facts and numbers are provided in previous posts. Which is why some cannot understand. Many only want to be told how to think; do not want to know why.
Which point was not explained without reasons why? Please provide specific answers. Then that reason why can be rephrased.
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Earth grounding for appliance protection can be missing even when an earth ground exists and meets code. Electricians, inspectors and maintenance people need not meet earthing requirements for appliance protection. They only need meet earthing requirements for human protection.
Summarized is a preliminary inspection that would identify earthing for appliance protection - a 'secondary' protection layer. A 'primary' protection layer should also be inspected. Nobody has yet asked about that.
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CSpackler
macrumors regular
Wouldn't a circuit breaker be redundant as most US households are 115v AC / 15amp circuits with breakers already? Standard circuit breakers are temperature controlled if I'm not mistaken (therefore will not trip at the same wattage), so I guess if it was a hard 15amp trip that would be an interesting feature. But if they are just another standard breaker it would be redundant.
They would appear to be redundant but that would be a good thing, right? If the breaker should fail in the main breaker box then the one in the strip would provide a backup.
CSpackler
macrumors regular
Ok. Let's start with the built-in surge protection ability of electronic appliances such as computers and audio/video equipment. You assert that this equipment has a certain level of built-in tolerance for surge energy but you don't detail how much, to what tolerance spec and specifically what design elements achieve it.
I think most people know that electronics tolerate a range of voltage fluctuations. The question is, is that range sufficient to absorb the kind of surges one might expect from, say, even a whole house surge protection system which the [point of use] surge equipment manufacturers say still let through enough energy that it could damage electronic equipment unless protected by their surge suppressors?
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Also, if the breaker on that branch circuit trips it shuts down everything on that circuit which in my case would be a lot of a/v equipment including an HTPC computer; better to have just the offending power strip trip than the whole circuit.
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It is more complex. We provide a number (ie 15 amps) to simplify it for layman.
For example, seven 100 watt light bulbs consume (700 watts/120 volts) maybe 6 amps. And will sometimes consume 50 amps for a short period. Does that 50 amps trip a 15 amp breaker? Of course not. In part because that short 50 amp demand on a 15 amp circuit is not a human threat or problem. A breaker's 15 amp number says much more when one understands complex operations behind a simplistic 15 amp number.
Same applies to voltage variations that electronics can withstand without damage (that other's post asks about). Design standards, even before PCs existed, meant 120 v electronics withstanding 600 volts without damage. Today's electronics meet and often exceed that number. Again spec numbers that define a 120 volt appliance (to a layman) also define more complex operations and robust protection. At least one Seasonic power supply claimed 1800 volts without damage. Bottom line: all appliances contain robust protection from various and different anomalies. Summarized by simple spec numbers.
Another example is a Maxim MAX491E line driver with an Absolute Maximum Rating (Vcc) of 12 volts DC. Voltages exceeding 12 volts damage that IC. And that line driver is also rated to withstand up to 15,000 volts without damage when part of a larger system. Another example how a simple number actually defines robust protection. An example of why knowledge must come from datasheets - not from hearsay, soundbytes, and advertising. And an example of why knowledge (reality) requires more and 'harder to read' paragraphs - with numbers.
An old technology called ethernet operates on tiny single digit volt signals. That same port must also withstand about 2000 volts without damage. Another example of robust protection routinely inside appliances.
In summary, first, a 15 amp breaker means even 60 amps can be provided to many appliances without tripping or risking human life. A 15 amp number summarizes for layman actual operations that are more complex.
Second, it also applies to protection inside all appliances. Electronics routinely convert hundreds of joules surges into rock stable, low DC voltages to safely power its semiconductors. A surge that can destroy a plug-in protector may also be too tiny to overwhelm protection inside appliances. Worse a plug-in protector may even compromised that existing internal protection. As demonstrated in a design review - when plug-in protectors earthed a surge destructively into a network of powered off computers. Robust protection compromised by an adjacent plug-in protector.
That 15 amp breaker must be on a power strip - to protect human life. All appliances already contain robust protection - to protect appliance life. Simple spec numbers summarize more complex protection - of humans or appliances.
AtheK
macrumors newbie
I plug in my macbook pro straight into the wall. NBD. 4+ years and counting. no issues here.
PinkyMacGodess
Suspended
And breakers, and GCFI outlets fail more than you would expect. We had a GFCI that failed that took out an expensive Hubbell USB charging outlet. The USB charging part was fried. I actually think I heard it *POP*, and smelled the fumes. The circuit stayed up, but the USB bits were dead, and the GFCI had tripped. Electrician thinks it was the GFCI. Had a breaker that kept tripping too. Put a meter on it, and it didn't even get to the 10amp load, and *POP*. Stuff happens...
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The inspector here checked thoroughly for rounding, even at the pole. He commented that many contractors think he won't check for proper grounds, and they hate him for it. We passed. I ran into a guy at the local electrical wholesale place that hated the inspector with a white hot passion. He got tagged repeatedly for screwups on grounds. That inspector retired, so I can only expect the new ones 'let it slide'...
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I like the Xiaomi products and they also make wifi controlled power strips and plugs
http://xiaomi-mi.com/news-and-actions/new-mi-smart-power-strip-by-xiaomi/
http://xiaomi-mi.com/news-and-actions/new-mi-smart-power-strip-by-xiaomi/
That inspector can only 'tag' for safety code violations (human safety issues). He cannot inspect for (and probably does not know) appliance safety issues. Those are not in and are not defined by safety codes. He can only cite code violations.
Did he also inspect the 'primary' protection layer? Again, things done to protect appliances are beyond what code requires.
Professionals in this business complain that protection on AC is not required. Dr Standler discusses it in his book ""Protection of Electronic Circuits from Overvoltage":
Meanwhile, a failed USB charger tripping a GFCI is described. GFCI did not damage that USB device. Power loss does not damage any electronics. Otherwise one could say what part was destroyed by removing power. And provide a datasheet number that explains it. USB charger failed in a catastrophic manner. Then GFCI tripped to protect human life - which is why that breaker exists. It did what it is designed to do. It did not cause USB charger damage.
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Potentially destructive surges may occur once every seven years. A number that can vary significantly even in a same town. A number defined by conditions such as how utilities enter the neighborhood and geology. Even how well a 'primary' protection layer is installed. A number that is better understood by learning decades of neighborhood history.
Furthermore, other household appliances may fail; act as protector for that mac.
Apparently this neighborhood has little risk. But reasons why can be many including a location of nearby transcontinental pipelines, no tree rodents, and linemen who do not make mistakes.
Tomorrow
macrumors 604
Yes, "dirty power," as it's called, is definitely a problem but one of a completely different sort.
A power conditioner "cleans up" incoming power by reducing or eliminating noise in the AC sinewaves. It's a completely different problem from power surges or spikes, and while they can both cause problems with certain appliances (mainly electronics), they cause damage in different ways and are remedied with different equipment.
Really? What happens inside electronics? 'Cleanest' or 'dirtiest' AC power is filtered. Then converted to a higher DC voltage. Then filtered again. Then converted to well over 300 volt radio frequency spikes. That is now 'dirtiest' power incoming to semiconductors. Then superior filters, regulators, and galvanic isolation converts that 'dirtiest' power into rock stable, low DC voltages to safely power all semiconductors. Anything that UPS might do is already done better inside electronics.
This 120 volt sine wave UPS outputs 200 volt square waves with a spike of up to 270 volts. Perfectly ideal power for electronics. Electronics are required to be that and more robust. But again, those pesky numbers.
That same UPS power is problematic for motorized appliances. If power conditioning is needed, then get it for a refrigerator, laser printer, furnace, and air conditioner.
Second, tie knots in a power cord. That is also a line conditioner - as long as we make claims without numbers. Yes, a knot is a power conditioner - using same reasoning that also promoted $hundreds of dollar power conditioners.
If a power conditioner is recommended, then each anomaly is defined with numbers. Those single digit or tens volt noise spikes are completely irrelevant to all electronics that even withstand 270 volt spikes from a UPS.
Why are recommendations made by ignoring numbers? Because most are only educated by hearsay and advertising. It must avoid all facts and numbers to protect sales with obscene profit margins.
Effective protection addresses anomalies that can overwhelm superior protection inside all appliances. That means spending about $1 per appliance on an earthed 'whole house' protector. Best protection is also least expensive. And recommended with numbers for protection even from direct lightning strikes - ie 50,000 amps.
Where is a plug-in UPS that will discuss these numbers? Crickets?
Tomorrow
macrumors 604
Electronics use transistors, which produce square waves. Loads such as motors do not convert the incoming sinewave into anything square, or sawtooth, or anything else; they're more forgiving of noise in the incoming signal.
PinkyMacGodess
Suspended
After a good bit more reading on surge protection I am uncertain about the value and type of point of use surge protectors. Westom apparently thinks they are of no value and that one should rely instead only on properly earthed surge protectors at the service entrance ("whole house" protection) yet all the independent, well-recognized authorities (NIST, IEEE, National Lightning Safety Institute, et al) as well as respected manufacturers of surge protection equipment (Leviton, et al) recommend point of use surge protectors as part of a layered protection strategy. [And then there is the issue of the ubiquitous MOV type vs Series Mode design. Not sure what to believe here but I just tried a series mode protector to prevent a laser printer from activating battery power on my UPS every time i print and I'll be damned if it doesn't work - it does at least for that.]
I have learned that the scare stories about point of use surge protectors catching fire/melting appear to be a thing of the past since UL implemented newer, tougher standards in 2009 (see UL 1449 3rd revision). It is also odd that virtually none of the literature from the authorities cited above mention the series mode type of surge protectors; is it because it is such a small part of the market due to its expense or is the technology not taken seriously? I don't know, yet. In the meantime I am hedging my bets and employing a few of the higher quality MOV type point of use surge protectors to replace any older ones and keeping the one series mode device for the laser printer issue. I will also probably get a wired surge device installed at the service entrance after I have an electrician do an audit of my current electrical system.
I have learned that the scare stories about point of use surge protectors catching fire/melting appear to be a thing of the past since UL implemented newer, tougher standards in 2009 (see UL 1449 3rd revision). It is also odd that virtually none of the literature from the authorities cited above mention the series mode type of surge protectors; is it because it is such a small part of the market due to its expense or is the technology not taken seriously? I don't know, yet. In the meantime I am hedging my bets and employing a few of the higher quality MOV type point of use surge protectors to replace any older ones and keeping the one series mode device for the laser printer issue. I will also probably get a wired surge device installed at the service entrance after I have an electrician do an audit of my current electrical system.
Please reread what was posted. I never said that. Do not ignore numbers. 'whole house' protector does 99.5% to 99.9% of protection. Those numbers from the IEEE. A plug-in protector does maybe another 0.2%. Please read NIST, IEEE, etc citations for details. They note a plug-in protector does something useful ONLY if used in conjunction with a 'whole house' solution. It is not either is good enough. Plug-in protectors must be used in conjunction with a properly earthed 'whole house' solution.
In one NIST brochure (figure 7), a plug-in protector earths a surge 8000 volt destructively via a nearby TV. Because the 'whole house' solution does not exist. Professional citations note why plug-in protectors can even make damage easier when not part of a 'secondary' protection layer. That layer is defined by the only item that does protection - earth ground.
Even a 'whole house' protector is ineffective if those other 'system' components do not exist. Each protection layer is defined by the earth ground. Every professional citation figure always includes earth ground. And discusses impedance.
Reread citations with attention to detail and numbers. Plug-in protectors add protection (as I stated) if part of a 'secondary' protection layer. Those other 'layer' components must also exist. But if earthing does not exist, then no 'secondary' protection layer exists. That is when a plug-in protector can even make appliance damage easier.
BTW, also discuss a 'primary' protection layer (as mentioned in sources). Even that gets ignored when the only protection is a 'magic box'. And not a 'system'.
Series mode 'protectors' are actually series mode filters. These have existed longer than PC existed. Only recently, series mode filter companies promoted an old product as surge protectors. And then saw massive sales increases. Anyone promoting anything today as a surge protector can significantly increase sales - even when it does not do protection.
That summary does not include numbers. It does not discuss THE most critical item in every protection system - single point earth ground. Many electricians do not know how to do that properly. Also not mentioned is an essential 'primary' protection layer. But a most glaring omission is numbers and proper grounding.
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Well that 0.2% is tantamount to saying they are useless isn't it?
What is disturbing is your claim that point of use surge protectors can actually do harm if you don't have a whole house protector installed at service entrance and earthed. Can you explain that?
That is demonstrated in figure 7 in an NIST brochure. That plug-in protector earths a surge 8000 volts through a nearby TV in another room.
In one study, a network of powered off computers were damaged. All were on plug-in protectors. Incoming on AC mains (hot wire) Protector put that surge current on all wires (safety ground and neutral). Now that surge is connected directly into a motherboard - bypassing protection inside a PSU.
That is only the incoming path. An outgoing path is also need. Outgoing to earth via a network card, into one computer that was connected to phones, and then into earth. Why? Phones already have an effective 'whole house' protector (installed for free) with a low impedance connection to earth.
We literally replaced each damaged IC to restore all computers. Those ICs clearly defined a connection from cloud to distant earthborne charges that passed destructively through the protectors and powered off computers. Clearly bypassed protection inside the PSUs.
Been doing this stuff for many decades. Have plenty of stories. Bottom line - a protector is only as effective as its earth ground.
0.2% is not zero percent. So it is another part of a solution. But again, numbers must always exist that say how much.
I just got a Tripp Lite (TLP808TEL) from Best Buy. I plugged five electrical cables to it. At the instance I turned on the switch, I heard "Ba" and saw some sparkling light coming out from the unit. Then one of the fuses in my apartment got blown. The unit also die immediately. Very scary. Got to return it to the store for a refund. Know what went wrong? The cheap IKEA power bar did not have this issue. Perhaps that is why Tripp Lite products are not popular and need to be special order in Canada? Checked Staples, Home Depot, Rona, Best Buy, Walmart, Canadian Tire, etc. I cannot find any Tripp Lite products in stores.
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PinkyMacGodess
Suspended
And I've heard they are 'over rated'.
I use APC power strips, and haven't had any issues for the years I've been using them. I did have a Tripp Lite ISOtel that 'blew up', and took out some minor equipment.
But everything blows, and I've had issues with APC UPS's...
Rule of thump I have, buy something that looks good, has features you want, and doesn't cost less than like $20.00.
Some have 90-degree plugs which is really quite awesome...