Question about UPS

[sometimewoodworker]

7 hours ago, peterfranks said:

Hmm, things seem to get better the more time I spend on Lazada, or do I misunderstand something?

 

If I order this thingy, I don't need a power supply, as I can feed the cameras directly from the UPS, and it should last at least an hour with my setup. Is that correct?

 

https://www.lazada.co.th/products/dc-ups-zircon-zmn-45-cctv-wifi-router-i-8-i1470910579.html?

 

Edit: I should have read further before posting, as it seems to output only 2A, so i wonder how they can talk about 4 cameras and a dvr in the spec, as that would exceed 2A power usage by far.

Are you sure that it is total 2A output?

Much more likely it is 2A per camera.

also since it shows 2A output at 24V you can drop that down to 4 x 5.5V x 2A

[peterfranks]

34 minutes ago, sometimewoodworker said:

Are you sure that it is total 2A output?

Much more likely it is 2A per camera.

also since it shows 2A output at 24V you can drop that down to 4 x 5.5V x 2A

There is of course little info available, but I see only 1 output, so that is why I think it is 2A total.

 

There are 4 x 2000mAh batteries built in. 4 cameras x 1A + 1 router at 1A + DVR at 2A = total 7A

 

You think those batteries can provide 84 Watt for 3-4 hours?

 

I don't see the point of dropping the voltage to 5.5V, as my cameras need 12V

 

This would of course be the ideal solution for me, if it works, so if I could get more info that would be appreciated.

 

https://www.jib.co.th/web/product/readProduct/48054/338/UPS--เครื่องสำรองไฟฟ้า--ZIRCON-MINI-DC-UPS-ZMN45-2200MAH-LAN-POE-USB--ZMN45-2200mAH--BLACK

[peterfranks]

1 hour ago, Crossy said:

 

That little module would do the switch over very nicely, but yes, it's limited to a 10A power supply due to the relay and probably the charging diode.

What is the advantage of this dual power device? Does it increase the current to 20A?

 

https://www.lazada.co.th/products/power-off-protecter-module-dual-ac-power-supply-automatic-switching-module-ups-emergency-cut-off-battery-power-supply-i2921922519.html?

 

In the description of the other device, it says switching power will go off for a few seconds.

 

This one says 10ms.

 

Which is the most likely switching time?

[Crossy]

1 hour ago, peterfranks said:

What is the advantage of this dual power device? Does it increase the current to 20A?

 

https://www.lazada.co.th/products/power-off-protecter-module-dual-ac-power-supply-automatic-switching-module-ups-emergency-cut-off-battery-power-supply-i2921922519.html?

 

In the description of the other device, it says switching power will go off for a few seconds.

 

This one says 10ms.

 

Which is the most likely switching time?

 

That one is a 220V unit so won't work for your application ???? 

 

[Crossy]

2 hours ago, Crossy said:

That little module would do the switch over very nicely, but yes, it's limited to a 10A power supply due to the relay and probably the charging diode.

 

Looking at this unit again, if that nice fat diode on the left is rated at 20A or more it would be OK. The 10A relay would have a reduced life at over 10A but it's not like you will be excercising it every day.

 

At the price I'd just get one and try it out.

 

If the diode does go fzzzt replace it with one of these https://www.lazada.co.th/products/10-20sq045-20a-45-pec-r-6-schottky-i370864879-s724052568.html

 

[peterfranks]

10 minutes ago, Crossy said:

 

Looking at this unit again, if that nice fat diode on the left is rated at 20A or more it would be OK. The 10A relay would have a reduced life at over 10A but it's not like you will be excercising it every day.

 

At the price I'd just get one and try it out.

 

If the diode does go fzzzt replace it with one of these https://www.lazada.co.th/products/10-20sq045-20a-45-pec-r-6-schottky-i370864879-s724052568.html

 

I found a similar one, same price, which doesn't have that diode.

 

Would that be a better choice?

 

https://www.lazada.co.th//products/i2437450791-s8444211263.html?

[Crossy]

5 minutes ago, peterfranks said:

I found a similar one, same price, which doesn't have that diode.

Would that be a better choice?

https://www.lazada.co.th//products/i2437450791-s8444211263.html?

 

The diode is there to remove any possibility of the battery back-feeding the power supply (some PSUs don't like it). Without actually examining the circuit I couldn't comment on the "no diode" version. It will probably work just fine.

 

More concerning is the long switch over delay these chaps seem to have and how your cameras etc. will react.

[peterfranks]

3 minutes ago, Crossy said:

 

The diode is there to remove any possibility of the battery back-feeding the power supply (some PSUs don't like it). Without actually examining the circuit I couldn't comment on the "no diode" version. It will probably work just fine.

 

More concerning is the long switch over delay these chaps seem to have and how your cameras etc. will react.

Never had thought that the cheapest part in the whole setup would cause the biggest headache ????

 

Do you reckon that the power supply with built in battery, will have a similar switch over delay?

 

I more and more start to lean to one of these. According to the spec it can provide 90W, which I think will be in the range of what my setup actually uses, for 27 minutes

 

https://www.lazada.co.th/products/cyberpower-backup-ups-systems-bu800e-7-2-i2368204846.html?

[Crossy]

7 minutes ago, peterfranks said:

Do you reckon that the power supply with built in battery, will have a similar switch over delay?

 

Probably not, I don't see a relay in the photo, it likely uses switching diodes for an instant change-over (it doesn't have to account for multiple supply voltages like those "universal" boards do).

[peterfranks]

7 minutes ago, Crossy said:

 

Probably not, I don't see a relay in the photo, it likely uses switching diodes for an instant change-over (it doesn't have to account for multiple supply voltages like those "universal" boards do).

 

Sorry to keep annoying you, so what is the difference between the power supply with the built-in battery and the cyberpower UPS? Do you think the power supply with built-in battery last 27 minutes at 90W usage?

 

As far as I understand, those UPS devices all have a 7Ah battery, so what makes them rated 600VA/360W or 800VA/480 Watt?

[Crossy]

All the devices you are looking at likely use the same 12V 7.5Ah sealed-lead acid battery.

 

That would hold around 90Wh of energy if taken to zero charge (not good for it).

 

So your 90W for 27 minutes would take it to about 50% charge asuming no additional losses.

 

The UPS of course isn't going to be 100% efficient, probably nearer 90% wnhen on battery so it would drain the battery further in your 27 minutes.

 

If you were to run the 480W UPS at full power the internal battery would last around 0.2 hours or 10 minutes which seems reasonable for a UPS intended for a PC, gives you time to save and shut down.

 

Either solution would do your job, the power supply with internal battery is a bit more energy efficient and means fewer boxes. 

 

 

[peterfranks]

5 minutes ago, Crossy said:

All the devices you are looking at likely use the same 12V 7.5Ah sealed-lead acid battery.

 

That would hold around 90Wh of energy if taken to zero charge (not good for it).

 

So your 90W for 27 minutes would take it to about 50% charge asuming no additional losses.

 

The UPS of course isn't going to be 100% efficient, probably nearer 90% wnhen on battery so it would drain the battery further in your 27 minutes.

 

If you were to run the 480W UPS at full power the internal battery would last around 0.2 hours or 10 minutes which seems reasonable for a UPS intended for a PC, gives you time to save and shut down.

 

Either solution would do your job, the power supply with internal battery is a bit more energy efficient and means fewer boxes. 

 

 

Thanks for the detailed explanation, so the power supply with built-in battery it will be.

 

Another advantage I see with this is, that once the lead acid battery dies, I can replace it with a higher Ah lifepo4 battery

[peterfranks]

1 hour ago, Crossy said:

More concerning is the long switch over delay these chaps seem to have and how your cameras etc. will react.

This will be my last time, I promise, but I just stumbled on this one.

 

Will this have a similar switchover delay, since I see only 12V quoted, or would it be a better option?

 

https://shopee.co.th/Hidduck✡12V-150W-12A-Backup-Battery-Switch-Module-Control-Board-Automatic-Switching-i.119346842.13833040673?

[Crossy]

13 minutes ago, peterfranks said:

This will be my last time, I promise, but I just stumbled on this one.

 

Will this have a similar switchover delay, since I see only 12V quoted, or would it be a better option?

 

https://shopee.co.th/Hidduck✡12V-150W-12A-Backup-Battery-Switch-Module-Control-Board-Automatic-Switching-i.119346842.13833040673?

 

I see a 5A relay!!

 

Without actually looking at the beast I couldn't comment on the switching delay. There's a worrying number of capacitors on that board, I wonder what they do.

[sometimewoodworker]

5 hours ago, peterfranks said:

There is of course little info available, but I see only 1 output, so that is why I think it is 2A total.

 

There are 4 x 2000mAh batteries built in. 4 cameras x 1A + 1 router at 1A + DVR at 2A = total 7A

 

You think those batteries can provide 84 Watt for 3-4 hours?

 

I don't see the point of dropping the voltage to 5.5V, as my cameras need 12V

 

This would of course be the ideal solution for me, if it works, so if I could get more info that would be appreciated.

 

There was no detail in the Lazada link.

now you have posted another link showing the output as a single POE output that is a different story.

 

While the batteries may be capable of 84W the device you show maxes out at 48W (2A @ 24V)

I had no idea of the power needs of your cameras if they use USB voltage it would be 5.5V

 

simple math allows you to drop the 24V 2A output to 4 x 5.5V 2A

 

however at 12V you can only power 2 cameras. If they need 2A each

 

Yes I now know there is only 1 output, so you would need a converter to drop the voltage from 24V to 12V or 5.5V(USB) to give either 2 at 12V 2A or 4 at 5.5V 2A, if you want to power more than a single device.
 

if you want to use the built in conversion then you are limited to 1 output at 12V 2A

[peterfranks]

@crossy

 

My power supply with built in battery just arrive.

 

Am I correct that the switching happens in the exact same way as the 140 baht switching module I found earlier?

 

https://www.lazada.co.th/products/b0017-automatic-switching-module-dc-5v-48v-10a-power-failure-automatic-ups-cut-off-5v-48v-i2471707408.html?

 

[peterfranks]

@Crossy  Don't know why the tag didn't work lol

[Crossy]

39 minutes ago, peterfranks said:

Am I correct that the switching happens in the exact same way as the 140 baht switching module I found earlier?

 

Can't say by looking, if it switches over instantly (like I would expect) then it's evidently got some rather smarter electronics than the other unit which seems from the description to think about it for a while.

 

[peterfranks]

2 minutes ago, Crossy said:

 

Can't say by looking, if it switches over instantly (like I would expect) then it's evidently got some rather smarter electronics than the other unit which seems from the description to think about it for a while.

 

Yes there is no delay.

 

On power supply it gives 11.8V, when unplug the power it remains on 11.8V for a few seconds, then it will be 12.38V without interruption.

Battery not fully charged yet.

 

I see the battery is connected to the 1A. Is that correct or should it to the 30A?

 

[Crossy]

1A is probably the max charging current, leave alone, it's working ???? 

[peterfranks]

I assume what is shown in the first picture are resettable fuses.

 

Can someone make from the explaining text what they are rated at?

 

I have the 18 output version, and it is supposed to be 12v 20A.

 

From the explaining text I make that either the device provides only 10A, or each individual fuse only opens at 10A, which I think may be way too high.

 

I like to be corrected, as I'm probably wrong.

 

[Crossy]

Yeah, the round yellow chaps are PT "fuses".

 

Rather than try to interpret the Chinglish spec. (which might make sense when we know what the fuses actually are) in the manual it's better to research the markings on the devices themselves. 

 

How are they marked, are they all the same?

 

[peterfranks]

3 minutes ago, Crossy said:

Yeah, the round yellow chaps are PT "fuses".

 

Rather than try to interpret the Chinglish spec. (which might make sense when we know what the fuses actually are) in the manual it's better to research the markings on the devices themselves. 

 

How are they marked, are they all the same?

 

They seem all the same X72 XF110

 

I think Google telle me that is 1.1A. Is that correct?

[Crossy]

7 minutes ago, peterfranks said:

They seem all the same X72 XF110

 

They are rated at 1.1A 72V max.

 

https://m.littelfuse.com/~/media/electronics/datasheets/resettable_ptcs/littelfuse_ptc_72r_datasheet.pdf.pdf

 

It's important to understand that these chaps are not actually fuses or breakers, they are current limiting devices (when they get hot their resistance increases thus limiting the current).

 

If one output won't power your NVR there's nothing to stop you putting two (or even three) outputs in parallel, the PTCs will ensure that the current is shared equally.

 

[peterfranks]

1 minute ago, Crossy said:

 

They are rated at 1.1A 72V max.

 

It's important to understand that these chaps are not actually fuses or breakers, they are current limiting devices (when they get hot their resistance increases thus limiting the current).

 

Thanks for the explanation.

 

Should I maybe better replace them with actual fuses, and if so, which rating should they be?

 

Now since there is a mention of 18 outputs 10A, I'm suspecting that the total output may be 10A.

 

Is there an easy way to check that?

[Crossy]

Why replace something that is designed for the job?

 

I'm sure the box you have will do the job you need just fine (no warranty implied or inferred).

 

To be honest I really can't help thinking that you are over-thinking your problem.

 

Even flat-out downhill with the wind behind them your 6 x 1A cameras and 1 x 2A XVR are only going to pull 8A (in reality they will likely be pulling rather less) so does it actually matter if your box can only supply 10A?

[peterfranks]

1 minute ago, Crossy said:

Why replace something that is designed for the job?

 

I'm sure the box you have will do the job you need just fine (no warranty implied or inferred).

 

To be honest I really can't help thinking that you are over-thinking your problem.

Because they are rated 72V, so if something goes wrong and send 24V to my cameras, they are toast. ????

 

Also if the power supply delivers only 10A maximum, it maybe short of current if I decide to add some cameras in the future.

[Crossy]

3 minutes ago, peterfranks said:

Because they are rated 72V, so if something goes wrong and send 24V to my cameras, they are toast. ????

 

Also if the power supply delivers only 10A maximum, it maybe short of current if I decide to add some cameras in the future.

 

72V is the maximum the fuses can withstand? I'm not sure of your thought processes here!

 

If you want more than 10A then find a unit that can supply more than 10A.

 

Why not employ a professional contractor to design and install your TV system??

 

[peterfranks]

4 minutes ago, Crossy said:

 

72V is the maximum the fuses can withstand? I'm not sure of your thought processes here!

 

If you want more than 10A then find a unit that can supply more than 10A.

 

Why not employ a professional contractor to design and install your TV system??

 

Maybe something got lost in translation.

 

I will employ a contractor for the installation, but I provide all the materials.

 

The power supply I purchased is supposed to be 12V 20A, but since the mention of 10A in the manual, I am afraid it may not be 20A

 

[Crossy]

From the minimal detail available I would suggest the beast really is intended to supply 18 "1A" cameras, it's got a decent heatsink, fan and a 30A relay.

 

Item 7 in that list is confusing as heck, I completely understand your worries, and what is Item 9 on about?

 

Something that it's important to understand is the purpose of the fuses. They provide over-current protection in case of a short in your wiring, without them the power supply would quite happily shove >20A down your Cat-5 which it won't like, causing heating and potentially a fire. The fuses provide no over-voltage protection, the voltage rating is simply the maximum voltage they are rated to operate at (look at your average 20mm glass fuse, 250V even on the 12V side of the supply). Having the fuses also means that a short in one camera supply would leave the others unaffected and operating.

 

If the PSU fails in a way that bangs out 24V, farewell cameras. One would hope that the PSU is designed in a way that would prevent that (in reality they usually end up with the driver devices going pop resulting in zero output voltage).