Best inverter for large UPS

[miahallen]

I'm a solar professional in Belize, and have built several UPS systems for various clients in my area. Some with solar, and some without, but all of them using off-grid/hybrid inverters and batteries typically used for solar. This tends to work very well, however, sometime the power flicker when switching sources is too rough, and computers shut-down or freeze.

Reading the manufactures documentation, it seems many different models should do the trick, and the hybrid inverters should have the fastest switching times. However, I wanted to get your opinion on the matter. What is the best brand/model for stable/reliable UPS operation? For the purpose of this poll, I've selected a handful of examples which are in the same output range. TIA

 

[Crowz]

Woudn't it be easier to use normal ups's on the computers and a hybrid inverter with solar and batteries on its own?

That way the normal ups units keep the equipment running in the even of a blink or right at the moment of transfer of the inverter. Then the solar/batteries handle long term outages.

That's how my house/office works now.

 

[miahallen]

Woudn't it be easier to use normal ups's on the computers and a hybrid inverter with solar and batteries on its own?

That way the normal ups units keep the equipment running in the even of a blink or right at the moment of transfer of the inverter. Then the solar/batteries handle long term outages.

That's how my house/office works now.

Crowz....its pretty much what I'm doing in this particular case.



The facility is already using a very large hybrid system for everything. But the computers & safety monitoring systems are very critical loads, and they want backup to the backup to the backup.....

They currently use a large APS unit for the servers and the UPS guy they have used in the past is quoting them an exorbitant amount to replace it as it is at EOL.

I suggested that I could simply get a solar inverter, connect it to the existing battery bank (pictured) and run that to the servers. It would save money and arguable be a much more robust system....except that the battery bank becomes a single point of failure. But we could also setup separate batteries for the UPS side.

 

[Crowz]

Super-Capacitor-Energy-Storage-Rack-Mount-Module-48V-7.46KWh - ATX Networks

[...]Read More...

atx.com

Using something like this might help. I imagine it would outlast any battery methods to supply the backup inverters.

Something in the super-capacitor area seems ideal for that situation since long runtimes are not needed just a need to keep it up during the switch over of the ones further up the line.

 

[Shimmy]

I think you correctly identify the issue-- individual models are unpredictable. Generally speaking though, an off-grid model should be better than something designed for grid tie (less sensitive to input power, fewer of the protection measures for back-feeding the upstream side, etc.

I have seven sets of small UPS batteries I need to replace in my home soon, and a centralized UPS sounds pretty attractive. The EG4 is the main one I am considering, although there are others like Tripp-Lite that make double conversion 48V inverter/charger UPSs. Unfortunately they are about twice the price of the EG4.

 

[miahallen]

I setup 2 systems with the Tripp Lite APS2448UL a few years back.....but neither one lasted very long, one of them nearly caused a fire. And even though Tripp Lite honored their warranty, I will not use them again.

 

[Shimmy]

I setup 2 systems with the Tripp Lite APS2448UL a few years back.....but neither one lasted very long, one of them nearly caused a fire. And even though Tripp Lite honored their warranty, I will not use them again.

Good info, thanks. I wonder how much better a non-UL unit is going to end up long-term. Schneider and Outback win there, but you likely want source selective fast transfer switches at the loads.

 

[miahallen]

I am not familiar with "selective fast transfer switches" - do you have more info?

 

[Shimmy]

I am not familiar with "selective fast transfer switches" - do you have more info?

Something like this:

AP4452AJ - APC NetShelter Rack Automatic Transfer Switch, 1U, 20A, 100V, 2 L5-20 IN, 8 5-15R OUT, 50/60Hz | Schneider Electric Global

Schneider Electric Global. AP4452AJ - APC NetShelter Rack Automatic Transfer Switch, 1U, 20A, 100V, 2 L5-20 IN, 8 5-15R OUT, 50/60Hz.

www.se.com

Basically it lets you have a rack with power from the base building system plus the supplemental system, and it will switch from the preferred source to an alternate quickly. If they want to go belt and suspenders this is the right approach. It won't be impacted by a problem on either system And it makes things more maintainable.

 

[miahallen]

Thanks for the tip Shimmy.

 

[RayofSunshine]

removed by me...