Computers & Electronics

UPS backup power supply worth it?

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  • Aug 12th, 2017 6:54 pm
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cam1878 wrote:
Jul 22nd, 2017 9:36 pm
Did you get an answer to your original question?

As someone who designs critical (UPS) electrical distribution for data centres, I can help out if you'd like.

(FYI - Near all of the technical aspects of Westom's posts are correct, however it's just very hard to follow the thought process, let alone filter out the arrogance and superiority complex that's going on.)
Yes, please share with us what this whole home earth ground protection system is.
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SickBeast wrote:
Jul 22nd, 2017 9:41 pm
Yes, please share with us what this whole home earth ground protection system is.
To be honest up front, I don't have experience with consumer grade SPD's, but I assume the functionality is the same.

When an external surge occurs (either from lighting strike nearby, spike in utility voltage from other means, etc) the SPD will effectively create a short circuit between the line voltage "hot" wires to the ground. The device does this in less than 1 ns.

The protective component is a metal oxide varistor (or similar). See here for a commercial grade SPD spec sheet.

In order for this to be effective, the device must be properly grounded (Like Westom said, without proper grounding, even the most expensive SPD is worthless.)

These devices are typically installed on main distribution panels, so in the case of a house, directly off of the utility panel. With this configuration it will provide protection for all loads fed from that panel.

In terms of cost, there is no $1 SPD. As Weston said, it would be $1 per protected device (i.e. all of them).
I assume he's referring to a device like this. $90, but most people can have up to 90 devices at home. Therefore $1/each.

For the technical info on that product family, you can look here.
http://www.eaton.com/Eaton/ProductsServ ... htm#tabs-2

I'm fairly sure the "joule" rating on everything is just marketing. Units are typically spec'd based on a variety of characteristics.
Proof not to utilize joule ratings as comparison information.
More proof.

To try to answer OP's original question:
UPS systems have different primary functions than SPD's. They're meant for battery backup.
If a UPS happens to have an SPD built in, then it can also provide surge protection. However, obtaining enough technical data on the SPD integral to the UPS would be difficult, making it hard to compare it to standalone or whole-home SPD's.
Last edited by cam1878 on Jul 22nd, 2017 10:31 pm, edited 1 time in total.
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cam1878 wrote:
Jul 22nd, 2017 10:31 pm
To be honest up front, I don't have experience with consumer grade SPD's, but I assume the functionality is the same.

When an external surge occurs (either from lighting strike nearby, spike in utility voltage from other means, etc) the SPD will effectively create a short circuit between the line voltage "hot" wires to the ground. The device does this in less than 1 ns.

The protective component is a metal oxide varistor (or similar). See here for a commercial grade SPD spec sheet.

In order for this to be effective, the device must be properly grounded (Like Weston said, without proper grounding, even the most expensive SPD is worthless.)

These devices are typically installed on main distribution panels, so in the case of a house, directly off of the utility panel. With this configuration it will provide protection for all loads fed from that panel.

In terms of cost, there is no $1 SPD. As Weston said, it would be $1 per protected device (i.e. all of them).
I assume he's referring to a device like this. $90, but most people can have up to 90 devices at home. Therefore $1/each.

For the technical info on that product family, you can look here.
http://www.eaton.com/Eaton/ProductsServ ... htm#tabs-2

I'm fairly sure the "joule" rating on everything is just marketing. Units are typically spec'd based on a variety of characteristics.
Proof not to utilize joule ratings as comparison information.
More proof.

To try to answer OP's original question:
UPS systems have different primary functions than SPD's. They're meant for battery backup.
If a UPS happens to have an SPD built in, then it can also provide surge protection. However, obtaining enough technical data on the SPD integral to the UPS would be difficult, making it hard to compare it to standalone or whole-home SPD's.
Interesting, thanks! That does look more useful and effective than a UPS actually. Thank you for explaining this so clearly. I may look into this type of product the next time I'm doing electrical work at my house.
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Whole home SPD won't do much for those in apartments or condos.
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willilumplump wrote:
Jul 23rd, 2017 12:37 am
Whole home SPD won't do much for those in apartments or condos.
A 'whole house' solution is a commodity. cam1878 has demonstrated one example of this commodity. Please do not assume his are the only solutions. Numerous solutions are available. Even the utility will rent one. A girl who reads the meter may install it. It is that simple.

Not detailed by cam1878 are two critical features. First a connection to earth ground must be low impedance (ie less than 10 feet). And must be to a single point earth ground. That means it cannot just *meet* code requirements. It must also *exceed* code requirements. Since and again, a protector is only as effective as its earth ground. That box is only a connecting device. It does not do protection. It connects every incoming wire to what does protection.

That defines protection during each surge.

Second, that protector must be at least 50,000 amps. That defines protector life expectancy over many surges. Since a protector must not fail even after direct lightning strikes. And since an effective protector must remain functional for decades.

cam1878 provides examples of effective protectors. But those are only boxes that are ineffective if the most critical system component does not exist. Those examples can be completely ineffective IF earth ground is not understood and properly installed - as cam1878 also notes. It remains this simple. Protection is always about where hundreds of thousands of joules harmlessly dissipate.

A protector adjacent to an appliance must do something completely different from protectors demonstrated by cam1878. An adjacent protector must either 'block' those Joules or 'absorb' those joules. So a plug-in protector (or UPS) is rated in joules.

Protectors demonstrated by cam1878 are rated in amps.

What do joule numbers tell us? Plug-in protectors are near zero protectors. Those are completely different from something also called a surge protector - demonstrated by cam1878.

Joules is relevant for ineffective protectors that are so expensive and that are located inside (adjacent to an appliance). Amps are relevant for a protector that actually connects to protection - a low impedance (ie less than 10 foot) connection to single point earth ground.

Any condo owner has an electrician install what cam1878 demonstrates. Any apartment dweller can even rent one from the AC utility. If this effective solution does not exist, then plug-in protectors can even make appliance damage easier. Or in rare cases, create a fire.

Again, what has the tiniest joules? A consumer style UPS. Just enough above zero to claim it has surge protection. Using that same reasoning, tying a knot in a power cord is also 100% protection. Instead, informed consumers properly earth this effective solution that costs about $1 per protected appliance.

But again, and not always understood. That best solution is only as effective as its earth ground. Protector is simple dumb science. Protection is the 'art' of earthing.
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westom wrote:
Jul 23rd, 2017 9:40 am
Amps are relevant for a protector that actually connects to protection - a low impedance (ie less than 10 foot) connection to single point earth ground.
westom wrote:
Jul 23rd, 2017 9:40 am
Protector is simple dumb science. Protection is the 'art' of earthing.
What I'm gathering from this is that the discussion is more about semantics than anything else.

I'm not disagreeing with you that the protection itself is done by proper grounding (i.e. low impedance, short and straight conductors, etc.)

But holistically both the protection (proper grounding) and a protector (the device that actually utilizes the protection) are needed in order for a load to be protected.

I also wouldn't exactly call grounding an art vs. science... It's still a fairly simple concept of electrical design.
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Gee wrote:
Jul 23rd, 2017 2:09 am
Most modern condos have a fuse panel in the unit.
Yeah, but how do you get "10 feet to earth" when you're 70 feet above grade?
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willilumplump wrote:
Jul 23rd, 2017 5:59 pm
Yeah, but how do you get "10 feet to earth" when you're 70 feet above grade?
In the case of SPD's installed adjacent to panels (not the plug-in kind), they're fed from their own breaker, but the feed to the device must be as short and straight as possible to minimize the impedance. In the spec's that I've written for commercial installations, we have them installed no more than 24" from the panel, much less than 10' - but this is for data centres, not a house.

I'm assuming this is the length that Westom is referring to.
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cam1878 wrote:
Jul 23rd, 2017 4:11 pm
But holistically both the protection (proper grounding) and a protector (the device that actually utilizes the protection) are needed in order for a load to be protected.
Some venues have no protector. But every structure that has effective protection always has earthing. The only component of each protection layer that must always exist is earth ground. Protectors only exist when an incoming wire cannot make a direct to earth connection. But earth ground must always exist.

This applies to broadcast stations, telco switching stations (COs), munitions dumps, rocket launching pads, airports (every plane must be grounded to the tarmac), mines, electronics atop the Empire State Building and WTC, high voltage transmission lines, and even nuclear hardened communication stations.

Best protection for cable, satellite dish, and OTA antenna has no protector. But must always have that low impedance connection to single point earth ground.

Less than 10 feet is a ballpark number so that consumers can better understand this. For example, if an earth ground hardwire goes up over the foundation and down to an earthing electrode, then protection is compromised. That wire is too long, has sharp bends, and it not separated from non-grounding wires. Protection increases when that hardware goes through a foundation and down to earth. Every foot shorter increases protection. No sharp bends and no splices increases protection. Essential is for an earth connection not be inside metallic conduit - since conduit may increase impedance - compromise protection.

One asked about earthing 70 feet up. Comcast installers, fresh from their training course asked me same. They were routing a cable directly into a third floor. And connecting a ground wire from that third floor entrance 30 some feet down to earth ground. They did not understand that a Comcast cable must drop down to single point earth ground before rising back up to enter a third floor. Then a surge makes a low impedance to earth before entering a building.

In one venue, a 'whole house' solution was properly earthed. A surge still entered and did damage. Discovered was a graphite vein behind the house. A best connection to distant earth borne charges was incoming on AC mains, destructively through that house, and then into that graphite vein.

Single point earth ground (equipotential) at the service entrance was expanded. The house was surrounded by a buried ground wire. Then surges entered earth at the service entrance. Connected to that graphite vein without entering the house. An example of the 'art' that sometimes makes earthing challenging.
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cam1878 wrote:
Jul 23rd, 2017 6:05 pm
I'm assuming this is the length that Westom is referring to.
That would make sense, but for one thing. How do you control for total impedance if you only spec the short run from the device to the panel? In an apartment, you have no control of how long or what kind of wire is used to ground the apartment (assuming you have a breaker panel to work from). If there's significant impedance, it doesn't satisfy the statements made by westom.

FWIW, I once checked the voltage difference between apartment ground and Rogers coax ground (investigating a ground loop making noise): 1.3V. If the two ground levels are that different, it suggests impedance to me. I assume the two grounds are connected in the basement where Rogers' distribution panel is located. One or both of those wires is the problem and, since it's an old building, I would wager that either one could be the culprit.
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westom wrote:
Jul 23rd, 2017 10:52 pm
Some venues have no protector. But every structure that has effective protection always has earthing.
Therefore they are not protected. For consumer electronics to be protected from incoming surges on utility lines, they need both effective protection and a protector to utilize it.
westom wrote:
Jul 23rd, 2017 10:52 pm
Protectors only exist when an incoming wire cannot make a direct to earth connection.
This is the only type of application that people have been discussing in this thread, which is a situation where a surge is received from the incoming utility lines. Protecting from a surge from a direct lighting strike has completely different solutions.
westom wrote:
Jul 23rd, 2017 10:52 pm
This applies to broadcast stations, telco switching stations (COs), munitions dumps, rocket launching pads, airports (every plane must be grounded to the tarmac), mines, electronics atop the Empire State Building and WTC, high voltage transmission lines, and even nuclear hardened communication stations.

Best protection for cable, satellite dish, and OTA antenna has no protector. But must always have that low impedance connection to single point earth ground.
I agree with you on all of these references, however they are irrelevant for this discussion, as they are regarding direct lighting strikes - i.e. not applicable to the questions of people in this thread.

I think it's safe to say that people on this thread are looking to protect themselves from a surge received from their utility lines (whether lightning hitting a nearby pole, a faulty component on the grid, etc.). People aren't going to go install a lightning protection system on their house. (With the exception of properly grounded OTA antennas or satellite dishes, which technically aren't even lightning protected, just grounded.)
westom wrote:
Jul 23rd, 2017 10:52 pm
In one venue, a 'whole house' solution was properly earthed. A surge still entered and did damage. Discovered was a graphite vein behind the house. A best connection to distant earth borne charges was incoming on AC mains, destructively through that house, and then into that graphite vein.

Single point earth ground (equipotential) at the service entrance was expanded. The house was surrounded by a buried ground wire. Then surges entered earth at the service entrance. Connected to that graphite vein without entering the house. An example of the 'art' that sometimes makes earthing challenging.
This isn't art. It's engineering.
  1. Damage occurred.
  2. Inspect design/installation.
  3. Discover equipment was properly designed/installed.
  4. Only remaining variable is the surrounding earth.
  5. Conduct soil type and resistivity tests.
  6. Discover graphite vein.
  7. Fix as described above.
There's no art to it, it's science and logic. Please stop making it sound like it's harder than it is.
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willilumplump wrote:
Jul 23rd, 2017 11:34 pm
That would make sense, but for one thing. How do you control for total impedance if you only spec the short run from the device to the panel? In an apartment, you have no control of how long or what kind of wire is used to ground the apartment (assuming you have a breaker panel to work from). If there's significant impedance, it doesn't satisfy the statements made by westom.

FWIW, I once checked the voltage difference between apartment ground and Rogers coax ground (investigating a ground loop making noise): 1.3V. If the two ground levels are that different, it suggests impedance to me. I assume the two grounds are connected in the basement where Rogers' distribution panel is located. One or both of those wires is the problem and, since it's an old building, I would wager that either one could be the culprit.
You are correct that in an apartment/condo situation you have less control over what's possible, but that doesn't mean no control.

In your example, I don't think it's the difference in impedance of the ground conductors themselves that would cause that (you can have a 50' cable and a 1' cable connected to the same ground and have the same voltage potential - but with different impedances). Your situation sounds like your building has two ground rods in separate locations that aren't bonded together. Even if they're only 4' apart, it can create a voltage differential between two different soil types. It's likely one is in the main electrical room and the other in the telco entrance facility.

From the OESC:
10-200 Current over grounding and bonding conductors
(3) Where, through the use of multiple grounds, an objectionable flow of current occurs over the grounding
conductor,
(a) one or more of the grounds shall be abandoned;
(b) the location of the grounds shall be changed;
(c) the continuity of the conductor between the grounding connections shall be suitably interrupted; or
(d) other effective action shall be taken to limit the current.
Unfortunately there isn't really a better answer than "get the landlord to bring it up to code" to resolve that kind of problem. At least not that I can think of off the top of my head.

Some protection is better than none though, if it's a difference between using a plug-in surge protector vs a panel-mount SPD, I'd pick the one that redirects the surge farther upstream from the devices any day. The farther the surge has to travel to get to the sensitive electronics the better. If the current has two paths, one being a short circuit to ground at the panel, the other via another 50' of conductor to a receptacle and back, it will take the path of least resistance.
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cam1878 wrote:
Jul 24th, 2017 7:53 am
Therefore they are not protected. For consumer electronics to be protected from incoming surges on utility lines, they need both effective protection and a protector to utilize it.
Then you do not know about the consumer's primary protection layer. We have only discussed the secondary layer. A primary layer does not need a protector. But it always must have an earth ground. If that street transformer does not have its required earth ground, then that primary protection layer has been compromised. Only earth ground (without a protector) provides and defines that layer of protection.

Second, earthing is an art. Semantics can argue details. But most have little idea of what their earth really is. Science will eventually explain it once the problem is discovered. But home owners never do such an analysis.

Connecting speculation with experimental evidence eventually discovered that graphite vein. No science knew it was there until after a solution was finally discovered - using 'artist' techniques. Standard earthing techniques are often sufficient. But sometimes the 'art' pokes its ugly head into and compromises a system.

Sometimes 'artist' techniques are necessary because science is unknown. Nobody, using well proven science, knew that graphite vein existed or that it would be a problem. It was discovered using an 'art' (that is impossible without science knowledge).

Third, some best protection only has earth ground - not protector. TV cable, satellite dish, and OTA antenna has best protection only with earth ground. Only item that creates every homeowner's primary protection layer is the always required earth ground - no protector used or needed.

Fourth, techniques used in airport, telco COs, nuclear hardened communication stations, and munitions dumps are also used in homes. Lightning (and other surges) don't see any difference between those and a home. Many techniques proven n those other facilities were later implemented in homes - such as Ufer ground. The Ufer ground orginally protected munitions dumps. It now provides superior protection in homes.

Details may vary. But surge protection for everything (even mines) uses these same well proven (science) concepts that also apply to homes.
Last edited by westom on Jul 24th, 2017 9:42 am, edited 1 time in total.
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willilumplump wrote:
Jul 23rd, 2017 11:34 pm
FWIW, I once checked the voltage difference between apartment ground and Rogers coax ground (investigating a ground loop making noise): 1.3V. If the two ground levels are that different, it suggests impedance to me.
You measured resistance. View a 50 foot Romex cable from receptacle back to the breaker box. That may measure well less than 0.2 ohms resistance. That same wire can measure 120 ohms impedance. What happens when a tiny 100 amp surge passes down that wire? 100 amps times 120 ohms means something less than 12,000 volts.

Less than because that current must find other (and destructive) paths to earth such as through a nearby TV.

We often say lightning will take the path of least resistance. Not entirely true. Lightning takes a path of least impedance. Wires are often thick enough. Impedance is not reduced by making a wire thicker. Impedance is reduced by making that wire shorter, eliminating sharp bends, keeping it out of metallic conduit, etc. None is measured by a digital meter.

That is when protection becomes an 'art'. We may not realize mistakes. We discover those mistakes after damage has happened. Using science, we discover and correct our mistakes. That is the 'art' of connecting a surge harmlessly to earth. Even wire splices may compromise an otherwise effective protection system.

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