Ups with long backup time

fake-name

Active Member
Feb 28, 2017
133
102
43
69
Well from what i read here


Apparently i'm gonna need a pure sinewave inverters otherwise the UPS won't accept the power,
there are alot of inverters in my local shop but none from the big names, e.g APC, cyberpower
Cyberpower do have some power inverters, but it maxed out at 1320 watt, not sure if thats enough for me.
Running a UPS off a inverter is just dumb. Also, none of the companies you list are big names in inverters. It would effectively be plugging a UPS into another UPS.

Did you not read my response at all?

Your UPS is an inverter. Your UPS is an inverter. Did I mention your UPS is an inverter?

Additionally, the pure-sine requirement is not going to be general. Some UPSes may work fine, some may not, it depends on their internals. There's likely no way to know without testing.

Did I mention there's an inverter in hour UPS? Because there's an inverter in your UPS. Did you know there's an inverter in the UPS you have? Why not just use the inverter that's already in your UPS and rated for the load you have and add more batteries?

Like, that's literally why EBMs exist. So you can arbitrarily extend the runtime of the UPS's inverter.
 

denywinarto

Member
Aug 11, 2016
177
18
18
36
Running a UPS off a inverter is just dumb. Also, none of the companies you list are big names in inverters. It would effectively be plugging a UPS into another UPS.

Did you not read my response at all?

Your UPS is an inverter. Your UPS is an inverter. Did I mention your UPS is an inverter?

Additionally, the pure-sine requirement is not going to be general. Some UPSes may work fine, some may not, it depends on their internals. There's likely no way to know without testing.

Did I mention there's an inverter in hour UPS? Because there's an inverter in your UPS. Did you know there's an inverter in the UPS you have? Why not just use the inverter that's already in your UPS and rated for the load you have and add more batteries?

Like, that's literally why EBMs exist. So you can arbitrarily extend the runtime of the UPS's inverter.
Wow easy,
I dont know if it's wrong terms used by sellers in my country,
but almost all inverters sold here cutoff power before switching to backup battery,
and they always making it clear when selling inverters to differentiate it with UPS.
That's why i didn't count it as UPS..

And looks like i'm not completely wrong :

And yes after some comparison i decided to use EBM,
a used ebm + new battery seems to be a better option in the long term.

Btw , just wondering, is it possible to use older EBM models ?
I wish i dont have to use 16 batteries EBM and use this instead :


Its supposed to use to 12v batteries and i happen to have 2 of them still hooked to my old UPS.


But the seller said each ebm is only compatible with its respective model with same serial..

So for my SURT6000XLI i'm supposed to use this SURT192XLBP - APC Smart-UPS RT 192V Battery Pack | Schneider Electric Global
 
Last edited:

Lost-Benji

Member
Jan 21, 2013
424
22
18
The arse end of the planet
The 6kVA UPS you have is a double-conversion model, so AC goes in, it goes to DC, charges batteries if needed, then the DC gets converted back to AC and output. If you look in your settings on the UPS, you can tune it to actually output 208 or 240V regardless of the input voltage. The high internal DC voltage is used to help minimize conversion losses. Since internally it is ~190V DC all the time it just pulls power from the batteries if the input AC goes away and you don't have the power interruption that you see with cheaper UPS units that will kick in the inverter and disconnect the load from the AC line when there is a power problem.
Nope, not a DOC units, they are Line-Interactive.

Generators are a little too overkill for my needs,
I just need it to survive roughly 1000 watt load for 3 hours, (most blackouts dont last more than 3 hrs)
Plus they're huge and i'd rather use rack-based,
but i can see at that ratio the options are limited for rack based.
I think you need to look at this more relistically. A load of only 1KW is quite low and just silly have 6KVA holding it. The use of a 2 or 3KVA UPS is much smarter and also works with plugs and leads. No need for hard-wiring. Battery capacity is the key for run-time.
In the APC units, 24V is common for the 1400VA, 1500VA and the 2KVA. The bigger 3KVA use 48V setups.

As for the differences between Online and Offline UPS are as follows:

  • Offline or Standby
These have the mains power going direct from the input to the output with some power tapped off for battery charging. When power input fails, the inverter fires up and relays cut the output across to it. Common designs, cheap and simple. Usually have modified sinewave output and less than stellar quality. When mains dies, these do take a while in the scheme of things to cut over resulting in small disruptions to the output, high loads usually will not be happy to droping a few mains cycles.

  • Online or Double Online Conversion
Mains goes in, is rectified to DC for charging bateries but also fed into Invertor, stepped back into AC and fed to the output. This breaks the AC mains from a device and helps stop mains noise or surges coming in. The output is always on and has no short pulses when power goes of like the above mentioned units.

  • Line-Interactive
These are different in design which is actually quite techinal but what they do is quite tricky. Mains goes in, it feeds a battery charger circuit to keep batteries charged. The rest of the mains goes into a series of systems and transformers that can be used to add or subtract mains output voltage (as I said, technical topic, too long for me to discuss here) ib buck/boost style setup. This gives the AVR (Automatic Voltage Regulation) without the need to introduce the invertor stages which are in-efficient to run wich is why DOC are not used when you want efficiency.


As for the suggestion earlie for a mains/solar invertor, this can be done with newer, smarter units that take mains in as well as Solar and battery power and then output constant mains level power on the output. Esentially like a UPS but run 100% of the time. Vaery smart for reducing power usage as they usually are configured to use mains as backup to solar and can be programmed.
This actually is when my new server room will on, 2x 5-6KW invertors with dual battery banks and multiple solar strings. No more UPS's as I will have dual supplies.
 
  • Like
Reactions: denywinarto

denywinarto

Member
Aug 11, 2016
177
18
18
36
Nope, not a DOC units, they are Line-Interactive.

I think you need to look at this more relistically. A load of only 1KW is quite low and just silly have 6KVA holding it. The use of a 2 or 3KVA UPS is much smarter and also works with plugs and leads. No need for hard-wiring. Battery capacity is the key for run-time.
In the APC units, 24V is common for the 1400VA, 1500VA and the 2KVA. The bigger 3KVA use 48V setups.

As for the differences between Online and Offline UPS are as follows:
There were also used 3KVA ups, but the price difference is only like 60$ with the 6KVA,
that and my 42U rack is only 1/3 used, i overspec'ed the UPS a bit in case i'm adding new servers

  • Offline or Standby
These have the mains power going direct from the input to the output with some power tapped off for battery charging. When power input fails, the inverter fires up and relays cut the output across to it. Common designs, cheap and simple. Usually have modified sinewave output and less than stellar quality. When mains dies, these do take a while in the scheme of things to cut over resulting in small disruptions to the output, high loads usually will not be happy to droping a few mains cycles.

  • Online or Double Online Conversion
Mains goes in, is rectified to DC for charging bateries but also fed into Invertor, stepped back into AC and fed to the output. This breaks the AC mains from a device and helps stop mains noise or surges coming in. The output is always on and has no short pulses when power goes of like the above mentioned units.

  • Line-Interactive
These are different in design which is actually quite techinal but what they do is quite tricky. Mains goes in, it feeds a battery charger circuit to keep batteries charged. The rest of the mains goes into a series of systems and transformers that can be used to add or subtract mains output voltage (as I said, technical topic, too long for me to discuss here) ib buck/boost style setup. This gives the AVR (Automatic Voltage Regulation) without the need to introduce the invertor stages which are in-efficient to run wich is why DOC are not used when you want efficiency.
Appreaciate the explanation, never thought line interactive is that tricky

As for the suggestion earlie for a mains/solar invertor, this can be done with newer, smarter units that take mains in as well as Solar and battery power and then output constant mains level power on the output. Esentially like a UPS but run 100% of the time. Vaery smart for reducing power usage as they usually are configured to use mains as backup to solar and can be programmed.
This actually is when my new server room will on, 2x 5-6KW invertors with dual battery banks and multiple solar strings. No more UPS's as I will have dual supplies.
Mind pointing some examples for this new units? is it the one you gave on your earlier post? If so what are the key words of this feature?
 

fake-name

Active Member
Feb 28, 2017
133
102
43
69
Wow easy,
I dont know if it's wrong terms used by sellers in my country,
but almost all inverters sold here cutoff power before switching to backup battery,
Sorry, I got a bit excited.

Anyways, a Inverter isn't a UPS, but it is a critical component of a UPS. If you have a (AC) UPS, you also have an inverter.

Also, all UPSes (other then double-conversion UPSes) also cut off power before switching. They just do it fast enough that things keep working (generally <~16 ms).

and they always making it clear when selling inverters to differentiate it with UPS.
That's why i didn't count it as UPS..
They're either misinformed, or wrong. This may be true for the inverters they sell, but this is not a general fact, or accurate if you are trying to describe inverters and/or UPSes in general.

And again, a UPS is also an inverter.

And looks like i'm not completely wrong :
I'm legitimately not sure what this article is trying to argue, but it's doing a very poor job of it.

The comparison chart is incoherent, and actually doesn't even agree with the article later on (they say inverters can't do xx, but UPSes can, but then the diagram of how UPSes work has a inverter in it. Wut?). I almost suspect that article was written by a markov bot or similar.

As far as I can tell, this was either written by a bot or someone who read half of the wikipedia articles on the relevant topics. Basically, use wikipedia or actual manufacturers, this isn't a coherent source.



And yes after some comparison i decided to use EBM,
a used ebm + new battery seems to be a better option in the long term.

Btw , just wondering, is it possible to use older EBM models ?
I wish i dont have to use 16 batteries EBM and use this instead :
It should be generally possible to use different EBM models, provided they have the same voltage. If your UPS uses 48V DC battery strings, you can (probably) hack together any other 48V battery string and use that. In this case, since your UPS seems to be 192V, you're stuck with 16-battery setups. Sure, the batteries don't have to be in a manufacturer provided EBM chassis, but you need to get that 192V somehow.

Some newer UPSes do have ID chips in the battery module which make using arbitrary batteries more difficult.