Question UPS Recommendation

Mar 30, 2023
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Hello, I am researching UPS for our specialised equipment. The specifications I have for our specialised equipment is up to 500W. I have been informed that the load of our specialised equipment should be at least 30% of the power of the UPS (so by my calculations we are looking at getting one that is at most 1666W).

I understand there are 3 different types - standby, line interactive, double conversion. I think standby or line interactive would be sufficient for us. We are trying to withstand planned and unplanned blackouts. My understanding is line interactive and standby would both cover that (with line interactive covering over or under voltages too).

So my questions are:
  • Is this true that I should get a UPS that powers 30% of the equipment load? Is it right in saying I should be looking at a UPS of about 1000W (max 1666W)?
  • If that is not true - can UPS be too powerful (and therefore not recognised)? - Need to clarify - our budget is over $10,000. If I choose anything less then it won't get approved (I know weird problem). So if I get the top of the line max specs - will it be a problem?
  • I went on APC live chat and I couldn't believe that they could only recommend one UPS. (SMX1000I) and if I would like it to run for 2hrs I needed to get an external power SMX-48RMBP2U. Does all UPS need an external power if I need it to run for an hour or 2? Are there UPS out there that would be able to run for a longer period of time (eg 30mins or an hour) without external power?
I have little knowledge about UPS so any assistance would be much appreciated.

Thanks in advance.

Kind Regards,
Agnes
 
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It appears pretty simple at first as most UPSes are rated 5-7 minutes at maximum load. Your load of 500w is "750VA" for APC UPSes, but you want it to run 30 minutes, which is 6x longer than 5 minutes. So 6x 750VA = 4,500VA minimum. That means you are closer to 17% of the maximum load than 30%.

The thing is, you don't actually need an expensive UPS that can deliver 3,000w as you only need something that can deliver 500w continuously without overheating, with enough extra battery capacity to run 30 minutes or longer. The closest thing they offer is 1000VA (which can deliver 670w) so I don't see anything wrong with their recommendation.
 
Mar 30, 2023
2
0
10
It appears pretty simple at first as most UPSes are rated 5-7 minutes at maximum load. Your load of 500w is "750VA" for APC UPSes, but you want it to run 30 minutes, which is 6x longer than 5 minutes. So 6x 750VA = 4,500VA minimum. That means you are closer to 17% of the maximum load than 30%.

The thing is, you don't actually need an expensive UPS that can deliver 3,000w as you only need something that can deliver 500w continuously without overheating, with enough extra battery capacity to run 30 minutes or longer. The closest thing they offer is 1000VA (which can deliver 670w) so I don't see anything wrong with their recommendation.
Hello, So I should clarify the reason I ask if a UPS is too powerful is because we have a budget of over $10,000. As in we need to spend $10,000 otherwise it doesn't get approved (I will update my post after this. So can I get the top of the line UPS with max VA I can get or will it be too powerful and too problematic?

And also the APC rep mentioned that I cannot just get SMX1000I. Without the external power it will only be 17mins of power. So is there something that I can get that doesn't require external power?
 
Too much UPS will not be a problem. For that kind of budget you could consider asking a local solar panel installer for a quote on a large LiFePO4 battery bank (which can provide a minimum 2000 cycles instead of 200 for deep-cycle lead-acid) and charger/inverter system. That would be the equivalent of a double-conversion UPS.

With a large enough solar array you could actually continue running through a very prolonged power outage such as after a natural disaster. I understand most of the world's spare powerplant transformers have been sent to Ukraine so the lead time from China would be very long (and thus the outage if a disaster like a Carrington event blows up many of them).