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Minimum transfer time for electronic equipment 1
- Thread starter vij36
- Start date
What is ATS?
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Automatic Transfer Switch
vij36; You might want to look up "Static Transfer Switch". THey tend to be electronic and very fast.
Keith Cress
kcress -
vij36; You might want to look up "Static Transfer Switch". THey tend to be electronic and very fast.
Keith Cress
kcress -
davidbeach
Electrical
“Tend to be electronic...” It would be interesting to see one that wasn’t electronic. ;-)
One would think that the required transfer time would be comparable to what a UPS would provide.
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- Moderator
- #7
I think that you need an Uninterruptible Power Supply. Then the speed of the ATS becomes unimportant.
If you have mixed loads, only part of which require a fast transfer, it becomes more economical to mate a smaller capacity UPS with a larger capacity ATS.
Bill
--------------------
"Why not the best?"
Jimmy Carter
If you have mixed loads, only part of which require a fast transfer, it becomes more economical to mate a smaller capacity UPS with a larger capacity ATS.
Bill
--------------------
"Why not the best?"
Jimmy Carter
- Thread starter
- #9
Dear Mr IRstuff
1. You asked "What is ATS?". Mr itsmoked correctly stated that it is (an) " Automatic
Transfer Switch" .
2. You mentioned " One would think that the required transfer time would be comparable
to what a UPS would provide" . Do you know what is (an) " UPS " ?
If your answer is positive, please advise us "what is the " transfer time" ...that
an "UPS would provide" ? ".
Che Kuan Yau (Singapore)
1. You asked "What is ATS?". Mr itsmoked correctly stated that it is (an) " Automatic
Transfer Switch" .
2. You mentioned " One would think that the required transfer time would be comparable
to what a UPS would provide" . Do you know what is (an) " UPS " ?
If your answer is positive, please advise us "what is the " transfer time" ...that
an "UPS would provide" ? ".
Che Kuan Yau (Singapore)
- Moderator
- #11
UPS Uninterruptible Power Supply.
Some models have no discernible transfer time.
A rectifier charges a battery bank.
The battery bank powers an inverter which supplies the load.
On the loss of power the battery continues to supply the load.
Bill
--------------------
"Why not the best?"
Jimmy Carter
Some models have no discernible transfer time.
A rectifier charges a battery bank.
The battery bank powers an inverter which supplies the load.
On the loss of power the battery continues to supply the load.
Bill
--------------------
"Why not the best?"
Jimmy Carter
-
1
- #12
- Moderator
- #13
Compositepro
Chemical
Yes, good story. When it comes to computers I have never bought a desktop PC, when a laptop includes a UPS that is far more reliable, at less cost.
LionelHutz
Electrical
I've seen electronics messed-up by a UPS that switched between sources. I can't remember the exact time, but it switched in less than a cycle. So, without digging into all the equipment in detail to determine it's ability to ride through a very short momentarily loss of power, I would specify something that doesn't switch.
- Moderator
- #16
About the fast ATS; What is your alternate power source?
There is no sense to worry about transfer speeds in milli-seconds or cycles if your standby generator takes 5 to 10 seconds to come on line.
We did a department store years ago with computer based POS terminals.
The main computer and the terminals had enough condensors in their power supplies to withstand an 8 second power outage.
Our standby set came online in about 5 seconds.
You can't just add condensors to the DVR power supplies. they will not have the capacity to charge that much extra capacity under all conditions.
You can may be able to build a stand alone capacitor bank complete with charging circuits and connect it to the DVR power supply with isolating diodes.
Bill
--------------------
"Why not the best?"
Jimmy Carter
There is no sense to worry about transfer speeds in milli-seconds or cycles if your standby generator takes 5 to 10 seconds to come on line.
We did a department store years ago with computer based POS terminals.
The main computer and the terminals had enough condensors in their power supplies to withstand an 8 second power outage.
Our standby set came online in about 5 seconds.
You can't just add condensors to the DVR power supplies. they will not have the capacity to charge that much extra capacity under all conditions.
You can may be able to build a stand alone capacitor bank complete with charging circuits and connect it to the DVR power supply with isolating diodes.
Bill
--------------------
"Why not the best?"
Jimmy Carter
An ATS responds to a LOSS of power and creation of power by a generator. So the "transfer time" of an ATS is, as Bill said, almost irrelevant when it comes to electronics. An ATS will not even BEGIN its process until AFTER the primary source has ALREADY failed. Then you have to wait for the generator to spin up and the voltage to stabilize. Only THEN will the ATS change over, by which time your electronics have long ago (in a relative sense) shut themselves down.
As mentioned, you need a UPS to carry you through that process. UPS come in two main "flavors"; "On-Line" and "Stand-by". On-line are always supplying the load via the inverters through the batteries, so there is no transfer time involved. Stand-by have a little transfer switch inside (often solid state) and can transfer in a matter of milliseconds to seconds, depending on how much you are willing to spend. You need to first define what your electronics can tolerate, then get a UPS system that is appropriate for the worst case scenario, with a battery pack long enough to carry you through the ATS based process.
" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden
As mentioned, you need a UPS to carry you through that process. UPS come in two main "flavors"; "On-Line" and "Stand-by". On-line are always supplying the load via the inverters through the batteries, so there is no transfer time involved. Stand-by have a little transfer switch inside (often solid state) and can transfer in a matter of milliseconds to seconds, depending on how much you are willing to spend. You need to first define what your electronics can tolerate, then get a UPS system that is appropriate for the worst case scenario, with a battery pack long enough to carry you through the ATS based process.
" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden
- Thread starter
- #18
Thanks every one for their kind replies.
How to find this. Basically the requirement is for a command and control surveillance system which monitors the cctv camera feeds.
Any best practices especially regarding to power failure management which should be adopted by a surveillance setup.
Thanks,
jraef said:
How to find this. Basically the requirement is for a command and control surveillance system which monitors the cctv camera feeds.
Any best practices especially regarding to power failure management which should be adopted by a surveillance setup.
Thanks,
Not sure I've ever heard of best practices for that topic.
If you truly have just a DVR and some cameras then the solution is to size a desktop UPS up for the time you need surveillance to continue before a generator is comfortably online. Not much is usually needed. A couple of hundred $$ can get you quite a while.
If you indeed have a generator you need to do one other thing and that's to specify a UPS that has settable tolerances for power disturbances that trigger it into operation. This is because small generators rarely have great voltage and frequency regulation. This can cause 'dumb' UPSs to stay engaged as they think the generator is supplying flaky power. They then run down to dead battery and end up blinking the system. Better UPSs have settings to deal with this and actually understand the problem.
Keith Cress
kcress -
If you truly have just a DVR and some cameras then the solution is to size a desktop UPS up for the time you need surveillance to continue before a generator is comfortably online. Not much is usually needed. A couple of hundred $$ can get you quite a while.
If you indeed have a generator you need to do one other thing and that's to specify a UPS that has settable tolerances for power disturbances that trigger it into operation. This is because small generators rarely have great voltage and frequency regulation. This can cause 'dumb' UPSs to stay engaged as they think the generator is supplying flaky power. They then run down to dead battery and end up blinking the system. Better UPSs have settings to deal with this and actually understand the problem.
Keith Cress
kcress -
How much is the security worth, i.e., what are the consequences of a slow transfer time? If it's Fort Knox, then money is nearly no object, but if it's a residence, then seconds might be acceptable.
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I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
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