Power Supplies

[Chris]

We have had some problems with power supplies over the past few months and wanted to know of the use of UPS backup power systems is feasible for HPLC systems and if anyone has any experience of this.

[syx]

we always use UPS for HPLC and data system to avoid instrumental damage or data loss due to electrical shock while they run. our national electical company has bad performance...

[Chris]

Thanks, I guess that you only get a few minutes of backup (or do you get longer) but I guess these give better protection than normal surge protectors.

[syx]

I think it will give 10-15 minutes, I do not know exactly because our generators are always be started for 1-2 seconds after blackout.

[Peter Apps]

On a typical UPS system how much power you have and for how long depends on the size of the unit, and how many batteries you connect. Above a certain number of batteries it becomes more cost effective to back up the UPS with a generator.

You need to be aware that a UPS does not necessarily condition the incoming power, unless it has a spike and surge suppressor you can still get dirty power downstream. Inverter-based UPS systems give clean power.

Peter

[Tony-ExcessUPS]

Hi Chris,


Many of our customers use UPS battery backups to protect their HPLC systems. Power problems are quite common and most people call up after they've had some sort of disturbance to try and prevent it from ruining the equipment.

Normal surge suppressors are pretty useless and offer little protection against power spikes, brownouts, and surges.


Home use surge suppressors are exactly that, they're meant for non sensitive equipment that can tolerate disturbances.


Most people don't use UPSs to get a long runtime but rather use them to ensure they get clean power to their machines and have enough runtime to shut down whatever they're doing safely.

I know that there is some sensitive testing equipment that does not like to be abruptly shut down and leads to loss of data and a very long restart time.


Also, UPSs are used as a line filter between a generator and the appliance to ensure that the appliance constantly received clean power. Some generators output dirty power as well as take more than a few seconds to kick in. The UPS will provide power during that time to ensure a safe transition.


Most good UPSs offer AVR boost and AVR drop to handle power increases and power drops. They can compensate for low power input and output a proper voltage consistently.


If you start shopping around for a good UPS, make sure you get something that offers AVR Boost Drop, power filtering, surge protection and outputs a sine wave. Anything that doesn't offer that, should be disqualified from the get go.

If you have any questions about battery backups, I would be more than happy to answer.



Yours truly,
Tony

We have had some problems with power supplies over the past few months and wanted to know of the use of UPS backup power systems is feasible for HPLC systems and if anyone has any experience of this.

[Tony-ExcessUPS]

Hi,


Peter is also completely correct, there is a cost analysis between getting a lot of batteries to run a machine without power and getting a generator to support all of the equipment that needs to run should a power failure occur.


Generator shoppers should keep in mind start up times and quality of output power when deciding on which to buy. Many people supplement a generator with UPS (small ones that provide little runtime) to ensure that generator transfer time is handled properly.


Find out how much power draw your particular HPLC has and that will help you determine what kind of run time you can get on what time of UPS and for how much.


Thanks,
Tony

On a typical UPS system how much power you have and for how long depends on the size of the unit, and how many batteries you connect. Above a certain number of batteries it becomes more cost effective to back up the UPS with a generator.

You need to be aware that a UPS does not necessarily condition the incoming power, unless it has a spike and surge suppressor you can still get dirty power downstream. Inverter-based UPS systems give clean power.

Peter

[DR]

Tripplite and APC both make 2200va rated UPS that can run one or two (depending on the draw) LCs and an acquisition unit (PC or A/Ds) for at least several minutes as well as providing some conditioning of incoming line power.

I tend to hook a single Agilent stack or a pair of Alliance systems and a LAC/E to a single 2200va unit.

I've had a little trouble with more than one Tripplite unit, will probably try APC next time.

Anything under $650 is a good price for these units.

[Tony-ExcessUPS]

Hi,


As long as you don't load up the units higher than 80% Tripp Lite or APC units should be able to handle it.


DR is right, the 2200 is the most popular unit for this application.

New:
APC Smart-UPS 2200 SUA2200

Refurbished:
APC Smart-UPS 2200 SUA2200


Tripp Lite also makes a 2200 unit that is comparable to the APC, we work mostly with APC so I can't really comment. I am sure they're great units as well.


Keep in mind that the 2200 units use a 20A plug, so you need to have that available or be able to have it installed by an electrician.


Yours truly,
Tony

Tripplite and APC both make 2200va rated UPS that can run one or two (depending on the draw) LCs and an acquisition unit (PC or A/Ds) for at least several minutes as well as providing some conditioning of incoming line power.

I tend to hook a single Agilent stack or a pair of Alliance systems and a LAC/E to a single 2200va unit.

I've had a little trouble with more than one Tripplite unit, will probably try APC next time.

Anything under $650 is a good price for these units.

[JGK]

Working in Canada where the combination of overhead power lines and snow/ice lead to frequent power fluctuations, we used UPS units to bridge the gap between power loss and our emergency generators "kicking in".

Additionally, if you buy a unit with "current smoothing" capabilities it also protects you from voltage fluctuations which may occur.

My last lab used Waters alliance and UPLC systems fitted with APC (Americam power conversion) UPS units (1 per instrument and each LAC/E unit) The base units of the acquisition terminals were also connected.


With this setup we never had an issue with acquisition loss due to power failure or during monthly switchover testing (mains/generator).

[Tony-ExcessUPS]

Hi Everyone,


Also, if budgeting for the purchase of a APC is an issue, the Smart-UPS 2200 SU2200NET is a great option. The SU2200NET is two thirds cheaper than a new SUA2200, and it's cheaper than the SUA2200 refurbished.

APC Spec Sheet for the SUA2200

The SU2200NET is the predecessor to the SUA2200. The main difference between the two units is that the SUA2200 is black in colour, has USB & Serial ports to communicate with a computer and has 380 more watts of power.

APC SmartUPS 2200 SU2200NET Refurbished with New Batteries

The run time on both units is identical because they both use the same batteries. However, on the newer unit, they were able to configure it to a bit of a higher wattage.


If you're not planning to use 1980W on a single unit, let's say your machine only uses 1200W, then the SU2200NET is a great choice and offers great value. Computer monitoring of the SU2200NET is done by serial port, with APC's free software or Windows XP, if you're planning to use it. The APC 2200 is a solid work horse, reliable and dependable.


Refurbished UPSs are a great buy and provide lots of value for the money spent if they're prepared correctly and come with a solid warranty.


We specialize in refurbished UPSs, but not to sound too much like a spam message, you can look around online and find yourself a good price on the APC 2200 unit.


When shopping for a refurbished UPS, make sure that the unit comes with brand new batteries and a solid warranty. Give the company a call make sure there's someone who picks up the phone and asks them how their warranty works. Who pays for shipping? How long does it take?


Tony

Working in Canada where the combination of overhead power lines and snow/ice lead to frequent power fluctuations, we used UPS units to bridge the gap between power loss and our emergency generators "kicking in".

Additionally, if you buy a unit with "current smoothing" capabilities it also protects you from voltage fluctuations which may occur.

My last lab used Waters alliance and UPLC systems fitted with APC (Americam power conversion) UPS units (1 per instrument and each LAC/E unit) The base units of the acquisition terminals were also connected.


With this setup we never had an issue with acquisition loss due to power failure or during monthly switchover testing (mains/generator).

[/url]

[DR]

We specialize in refurbished UPSs, but not to sound too much like a spam message...

IMO - not at all - this is the type of helpful vendor input that I think the overwhelming majority of board users have no problem with.[/hijack]

Next time I have a 2200 shoot craps on me, I will certainly look into your wares.