Advice on UPS backup power supply - DVR & 8 cameras

[weeboludo 0]

Hi, I'm designing my first system for a friend and I will have a few questions I hope you can advise on, but first I wanted to ask about backup power.

 

The system is DVR & 7-8 external cameras with IR. I had a bash calculating the backup time:

8 Cameras at 12Vcc 450mA ... 8 * 12 * 0.45 = 50W
From website, the DVR consumes 25W
Total for system: 75W

Looking for a random example, I found the DirectUPS DP1000 1000VA 600 Watts UPS at more or less US$100 ....

Does this really mean:

600 / 75 ( * 0.9 for perfromance) == Around 7 hours

This is way more than I expected. Have I gone wrong in the calculations??

 

Creating an entire closed loop power circuit for the cameras seems like alot of work - though I'll have to lay the signal cable anyway.

 

Any really strong argument for having perhaps 3 smaller UPS rather than 1 big one?

 

Thanks in advance for any advice

[hardwired 0]

Nope, it doesn't work that way, the wattage of the UPS is the peak power it can supply, not for how long.

 

Take a look at a UPS selector here- http://www.tripplite.com/en/products/ups-system-runtimes.cfm to get a better idea on runtimes. I would just localize power at the DVR, it simplifies things greatly.

 

As long as the runs are not terribly long, you might want to consider using baluns and CAT5 cable, that way you have everything in one cable, and you could change later to IP cameras (assuming the runs are under 300 feet).

 

Another choice would be to use Siamese RG59U with 18/2 power wire in the same cable.

[Soundy 1]

Taking the 12V, boosting it up to 120V, only to step it back down to 12V for the cameras is extremely wasteful. I'd use a central power supply for the cameras that has its own 12V backup batteries, so when the power is out the cameras just run directly off the batteries. Then you can use a smaller UPS for the DVR (be sure not to run unnecessary things, like the monitor, off the battery side).

 

Something like this: http://www.enforcer.com.tw/EnforcerVideo/MODEL1_2.htm

[shockwave199 0]

I have my dvr and monitor on the UPS. My dvr doesn't like a hard shut down at all, so when there's an outage I can do a soft shut down, in which case having the monitor to see that bit of navigation is helpful. I also have six cameras on the UPS as well. Doesn't buy me much time, but enough to shut down properly if the outage goes on for a bit. Tell you the truth, it's all hooked up and it doesn't look particularly pretty, like if everything was in a power box, but it works so I leave well enough alone. When I fiddle with things, even for an improvement- it always makes things worse. However, I'd take the advice above over mine, for sure.

[Soundy 1]

My dvr doesn't like a hard shut down at all, so when there's an outage I can do a soft shut down, in which case having the monitor to see that bit of navigation is helpful.

If it's a Windows-base DVR, you can install the UPS software that will monitor the UPS status and initiate a proper shutdown automatically when the power gets low.

[shockwave199 0]

You mean a dvr card? My dvr is a stand alone unit.

[Soundy 1]

You mean a dvr card? My dvr is a stand alone unit.

Well, not a function of the card, technically... most UPSes can be connected to a PC that can be loaded with software that will monitor the UPS health and remaining run time, and among other things, can trigger a soft shutdown (same as clicking Start -> Shutdown) when the UPS capacity falls below a pre-defined level (for example, when there's less than 5 minutes' power left). Most such software can also alert you when the battery is close to failing, or if there are any other potential problems with the UPS.

[weeboludo 0]

Taking the 12V, boosting it up to 120V, only to step it back down to 12V for the cameras is extremely wasteful. I'd use a central power supply for the cameras that has its own 12V backup batteries, so when the power is out the cameras just run directly off the batteries. Then you can use a smaller UPS for the DVR (be sure not to run unnecessary things, like the monitor, off the battery side).

 

Something like this: http://www.enforcer.com.tw/EnforcerVideo/MODEL1_2.htm

 

Good point, I'll have a look around see if I can find something similar available around here. Cheers

[weeboludo 0]

My dvr doesn't like a hard shut down at all, so when there's an outage I can do a soft shut down, in which case having the monitor to see that bit of navigation is helpful.

If it's a Windows-base DVR, you can install the UPS software that will monitor the UPS status and initiate a proper shutdown automatically when the power gets low.

 

The idea was a standalone Linux based DVR, running without monitor. There will be power outages, and they will drain the battery completely and there will be noone around to reset it. So .. I'll be wanting somehting with BIOS wake ... wake-on-lan or something.

 

I'm fairly handy with Linux, so as long as it will wake up and connect to the internet I am happy entering the system myself by SSH and fixing anything by hand. So either wake-on-lan or some BIOS setting. Though maybe I might have to build a system myself rather than buy a standalone (later I'll maybe ask you all for opinions on the models available here to see if you have experiences)

 

Cheers

[weeboludo 0]

Nope, it doesn't work that way, the wattage of the UPS is the peak power it can supply, not for how long.

 

Take a look at a UPS selector here- http://www.tripplite.com/en/products/ups-system-runtimes.cfm to get a better idea on runtimes. I would just localize power at the DVR, it simplifies things greatly.

 

As long as the runs are not terribly long, you might want to consider using baluns and CAT5 cable, that way you have everything in one cable, and you could change later to IP cameras (assuming the runs are under 300 feet).

 

Another choice would be to use Siamese RG59U with 18/2 power wire in the same cable.

 

Thought I had to be wrong. Cheers for the calculator, unfortunately available equipment here (Argentina) is pretty limited, not sure if any models I see are on this, so I'll have to get my pen & paper out.

 

Thanks for the advice on cables & wiring ... that was going to be my next post once I understand the backup power requirements and once I have some measurements of the distances.

[Soundy 1]

My dvr doesn't like a hard shut down at all, so when there's an outage I can do a soft shut down, in which case having the monitor to see that bit of navigation is helpful.

If it's a Windows-base DVR, you can install the UPS software that will monitor the UPS status and initiate a proper shutdown automatically when the power gets low.

 

The idea was a standalone Linux based DVR, running without monitor. There will be power outages, and they will drain the battery completely and there will be noone around to reset it. So .. I'll be wanting somehting with BIOS wake ... wake-on-lan or something.

 

I'm fairly handy with Linux, so as long as it will wake up and connect to the internet I am happy entering the system myself by SSH and fixing anything by hand. So either wake-on-lan or some BIOS setting. Though maybe I might have to build a system myself rather than buy a standalone (later I'll maybe ask you all for opinions on the models available here to see if you have experiences)

 

Cheers

All the standalones I've worked with fire up right away when power is applied, so that shouldn't be an issue. The difference is in whether they can do a clean shutdown under control of the UPS. Not sure about other brands, but APC UPSes have a Java-based control utility so they should be able to trigger a clean shutdown with any system that supports Java. A DIY Linux box should be workable... don't know about a standalone, though.

 

 

Edit: on the other hand, I've rarely come across a DVR, standalone or not, that had serious issues with a simple hard-power-down. Power surges are another matter, but shutting down from a basic power outage shouldn't be a problem.

[shockwave199 0]

Yes to clarify, the hard shut down problem is an isolated problem to my dvr. Once or twice it was slow to come back up after a hard shut down. So I avoid it with a ups in line, which gives me time to get to it.

[ssmith10pn 0]

This should do it.

 

One Megawatt of battery backup with two 1 megawatt generators.

 

 

 

[Soundy 1]

Or just get Mr. Fusion...

 

[camera-newbie 0]

Hey Smith.. Aren't those what they had in Jurassic Park? Hope they're no Dino's running around with the power out eating your cameras!!

[weeboludo 0]

Been a while, but thought I'd report back. Went to a store specialising in CCTV systems and They have the following UPS:

http://www.argseguridad.com/producto_detalle.php?id=459

With 1 x 4A output, 4 x 1A outputs and claims to run for 5 hours.

 

The cameras were about 0.5A so I imagine I could connect 2 to each 1A output. The price is equivalent to 200 US or 130 pounds.

 

They recommended coaxial cable with power cables incorporated, and said using passive baluns that the cables could stretch up to 100m without losing too much signal.

 

The standalone linux system they have powers up automatically on hard shutdown.

[AndyA 0]

My dvr doesn't like a hard shut down at all, so when there's an outage I can do a soft shut down, in which case having the monitor to see that bit of navigation is helpful.

If it's a Windows-base DVR, you can install the UPS software that will monitor the UPS status and initiate a proper shutdown automatically when the power gets low.

 

The idea was a standalone Linux based DVR, running without monitor. There will be power outages, and they will drain the battery completely and there will be noone around to reset it. So .. I'll be wanting somehting with BIOS wake ... wake-on-lan or something.

 

I'm fairly handy with Linux, so as long as it will wake up and connect to the internet I am happy entering the system myself by SSH and fixing anything by hand. So either wake-on-lan or some BIOS setting. Though maybe I might have to build a system myself rather than buy a standalone (later I'll maybe ask you all for opinions on the models available here to see if you have experiences)

 

Cheers

 

 

they wake on ac resume on most stander bios

[Soundy 1]

They recommended coaxial cable with power cables incorporated, and said using passive baluns that the cables could stretch up to 100m without losing too much signal.

They misspoke - 1000m would be more accurate.

 

The standalone linux system they have powers up automatically on hard shutdown.

*ALL* PCs are capable of this - it's a BIOS option, independent of the OS.

[jenifer123 0]

I don't have any knowledge about the calculation of circuit, but anyways you are doing a good job for your friend, all the best.

[ubermik 0]

The problem with a hard shut down is the MBR on the hard drive

 

The MBR is constantly updated as the data on the hard drive is updated and if someone is unlucky and the hard drive is powered down during an update of the MBR it "can" not only corrupt the data on the hard drive but in rare instances brick the hard drive

 

With this in mind I find it quite appalling that DVR manufacturers, especially larger ones like hikvision, Dahua, Samsung and so on haven't built in a Linux interface for standard UPS makes such as APC

 

As for a UPS, they tend to have two values, one is their watt/hour value which is the same as a batterys AH value, how much "power" it can store and a second which is its maximum load current

 

So you could have a 2kw UPC which can only provide a maximum of 500watts, but would supply that amount for "around" 4 hours or alternatively one that is a 2kw UPS that can supply 2kw for 1 hour. So you need to figure out what the value actually is

 

Many APC models state their "capacity" not their maximum load which is often quite a bit less than their capacity

 

But also bear in mind that even if a UPS has 2kw capacity you wont get that full capacity. Partly due to losses in the conversion process and partly because the batteries will reach the lowest voltage that the circuitry can effectively step up to 240v but some of the 2000 watts will still be in the battery as well as bearing in mind that any value stated is only the capacity when brand new, over time the capacity of the batteries, what voltage they charge to and how quickly their voltage drops will all change.

 

So a UPS that is a couple of years old might have a significantly lessened capacity compared to when it was new, so choosing a UPS that allows you to change the batteries (or battery packs) yourself is always the best way to go rather than sealed units that aren't owner serviceable

 

Most APC models either take standard batteries or have a simple lead/connector arrangement you can prise off and stick onto new batteries so I have tended to use APC models partly because of that and partly because their collect and return warranty service is handy as posting a faulty UPS back to the manufacturer is quite expensive and not all manufacturers will cover that cost

[Fivealive 0]

UPS labels will always state KVA and KW and they will be slightly different.

 

UPS are usually marketed in their KVA rating however

 

The KW rating (which accounts for losses ie power factor) will be the one to use for your loading requirements.

 

Typically small UPS have PF at 0.8 though can range from 0.6 to unity. So a 1kva UPS with PF of 0.8 will have a maximum load capacity of 800w (0.8Kw)

 

Battery AH is the rating that the battery should be able to continuously supply exactly for 1 hour - Which doesn't mean or help most that purchase UPS

 

UPS will usually state the full load runtime of the UPS on batteries, which Typically on a small UPS is usually all that is required

 

Often UPS are specified by consultants, which in reality means we calculate the battery requirements for a specified runtime at a specified load. If this runtime is to be required at end of life of battery, the industry standard is to add on another 20% for battery deterioration.

 

Hope this helps :0)