Opinions on UPS brands

I was just wondering what brand Uninterruptable Power Supply (UPS) you guys use and/or prefer. We have primarily been using APC brand, but a vendor of ours wants to sell us Leiberts, saying they are better.

We tend to have unreliable power as we are at the very end of the line, and have many storms causing surges and power flickers.

I figure you guys would give better reviews than anything else I find on the net.

we use aps.

is this for pc's or plc's?
siemens don't like ups power. our other plant burnt several up before removing them.
regards,
james

120VAC Applications:
For home, I use Cyberpower, and have never had a problem.
At work, we almost always use Eaton Powerware.

More and more, we are switching to 24VDC systems, and just use some batteries and a battery control module.

but a vendor of ours wants to sell us Leiberts, saying they are better.

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if you give him a chance, he should be able to prove it ...

I watched the Liebert tech guys do a very impressive demo some years ago ... they hooked up a VERY high-speed (read: "expen$ive") oscilloscope to a system – then tested several competitor's UPS models ... (I can't remember if APS or APC were among the competitors which were tested) ...

the point of the demo was that for each model tested, when the line power was switched off, there was a very brief – but very intense – SPIKE of voltage as the UPS made the transition from line power to battery power ...

now the question presents itself: could that intense SPIKE of voltage be detrimental to the reliable operation of your PLC? ...

back to the demo: when the line power was switched off with the Liebert UPS hooked up, there was no spike – only a barely noticeable ripple in the voltage when making the transition from line power to battery power ...

DISCLOSURE: I have no connection to Liebert – but I was fully impressed – and thoroughly convinced - by their demo ...

going one step further: I know of one company who installs a UPS on each PLC system that they install – but they also insist on ALSO installing a surge-protector too ... they maintain that using that two-part solution gives them reliable results – but using the UPS alone doesn't get the job done ...

I don't use UPS on PLCs.

If there is ever a power outage, then why have the plc controlling a dark plant.

If you have power quality problems, there is a good possibility that is is coming from inside your plant. I would work to solve that as it would be much more beneficial to your overall process (at least I think it would). Now you did say storms and such, but is that really the only time you are having problems??

APC and Eaton (Mostly Eaton as of late)

APC(Infrastructure) and Liebert(Process)

We used to have an Italian drive system 1995 vintage and they used a Motorola VME cards. The basic APC SmartUPS SUA1500 ($420) were not quick enough (4-6ms transfer time) so we had downtime as the program burped.
After talking to APC, they recommended their SURTA1500XL which costs $760 and close to bumpless transfer time. After that the only burping was from our supervisors.

brucechase said:

I don't use UPS on PLCs.

If there is ever a power outage, then why have the plc controlling a dark plant.

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We have retrofitted some servo panels we built with battery backup to keep control voltage on the drives so that they don't lose the position reference when the power goes out. These customers are away from major metropolitan areas and the power outages are definitely not caused by anything they are doing.

I would guess that most systems using UPS/battery backup for a PLC are doing so to maintain data (counts, positions, temperatures) and not to do any production. There are many complex systems that are very difficult to restart if the PLC loses track of where the machine is in the cycle. If the PLC knows this data, it would be much easier to reset the system after the power is returned.

We have since changed our design to use servo motors with multi-turn absolute encoders that do not require power to maintain the position reference which eliminates the need for the UPS.

Liebert..hands down!

We have a few "office duty" MGE units on our emissions monitoring stuff - hasnt required any attention for 2 or 3 years - havent lost power yet to test it.

We have some (much larger) dependable power units:
http://www.dependablepowersystems.com/
At least one of their tech's is insanely smart/educated. He also has lots of stories about the oil fields and nuclear plants that use this same system- so there are lots of these things out there. They have a fully-featured bypass/backup/solid-state switch/bumpless xfer system. Never oscoped it though.
I'm sure that if we would have spec'd the correct system (1 phase vs. 3 phase) our load imbalance wouldnt cause the problems that it does. I'd definitely recommend that you look at them.

-John

We are changing ours over to 24DC were possible and installing chargers and battery packs.

I use the Siemens range of UPS's with there PSU's

We process flammable chemicals in our web machinery, so for us the benefit of a UPS is to ride through brief interruptions in utility power.

For our process equipment we only use true 'on-line' UPS hardware; so then there should be no spike or any interruption when normal power goes away. The only difference is that when there is incoming power the batteries get charged, no incoming power means that we're running off of battery only.

For some time know we have been using Tripp-Lite brand hardware. Several of the S2K models have hardwired output as an option. We have a large (10kva?) unit with additional battery packs that has a lighting panel as the load; and this lighting panel then powers our external 24VDC power supplies that power all of our automation equipment. Long term holdup time is roughly 3 hours, after that we're relying on the backup batteries / capacitors / EEPROM etc. on the PLC's.

Tom

tmccormick said:

We process flammable chemicals in our web machinery, so for us the benefit of a UPS is to ride through brief interruptions in utility power.

For our process equipment we only use true 'on-line' UPS hardware; so then there should be no spike or any interruption when normal power goes away. The only difference is that when there is incoming power the batteries get charged, no incoming power means that we're running off of battery only.

For some time know we have been using Tripp-Lite brand hardware. Several of the S2K models have hardwired output as an option. We have a large (10kva?) unit with additional battery packs that has a lighting panel as the load; and this lighting panel then powers our external 24VDC power supplies that power all of our automation equipment. Long term holdup time is roughly 3 hours, after that we're relying on the backup batteries / capacitors / EEPROM etc. on the PLC's.

Tom

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This, I use Falcon UPS, expensive but absolutely bullet proof.