UPS on power backup with a cut-off limit - ACP BR1500G

[Anonymous user]

Hi,

I am planning to buy a Dell Workstation that draws 750 watts of power. The place where I stay has a power problem and there are regular power outages that can sometime last up to 4-5 hours. Fortunately, my apartment building has a diesel generator that provides power backup for as long as there is a power outage. The only problem is that there is limit to which you can draw electricity when the backup generator in running. The cut-off limit is 400 watts. If the consumption in a household crosses 400 watts then the power supply trips and it can only be resumed by going all the way downstairs and flipping up a MCB switch.

Now, I need to keep running my workstation even during power outages. But since the workstation draws 750 watts, it will trip the backup power supply when the backup generator is running. So I am thinking of getting myself the ACP BR1500G-IN 1.5 KVA UPS to solve this problem.

My question is: How much power will this UPS draw? I need to know this, because, if it draws more than 400 watts then it will trip the power supply and my problem will remain unresolved. If this model will not help me, then is there any other model that draws less than 400 watts but gives an output of 750watts?

Look forward to all your replies.

Thank you in advance
Nik

[Anonymous user]

Thank you *'I picked a winna'* and *'voidstar'*.

Now I know that the UPS would need only about 30w to keep charging. So it means that it can keep charging on the generator power and at the same time also run the workstation.

Also, perhaps I wasn't clear in my explanation, but I 'do not' want the UPS to run on the battery at all. I want it to run on the main supply and during outages I want it to run on the generator power.

So, to restate my question: Will the ACP BR1500G-IN 1.5 KVA UPS keep drawing 30 watts of power from the generator and continue charging, while it is being loaded by a workstation drawing 750 watts of power?

Thanks again for all your support.

Note: The backup generator is actually an industrial scale generator generating enough power to provide 400 watts of power to 240 apartments (400x250=100kW). Plus it can also run about 6 escalators. The only problem is that one apartment cannot draw more than 400w, during outages.

[BillP]

no, it definitely does not. the most that it should be using would be an extra 30W while it is charging the battery. beyond that, we'd just need to account for the efficiency of this UPS which seems to be almost 100% (85%) meaning there is not much power coming into the UPS that does not leave to support the load.

[voidstar_apc]

>
...is there any other model that draws less than 400 watts but gives an output of 750watts?
>

I think there are a lot of people who would love a UPS that exceeds 100% efficiency 🙂

Maybe another way to think about it is you want a UPS that runs on battery when the generator is operational. Our line-interactive UPSes may do this if you set the UPS to high sensitivity and your generator produces dirty power (typically the case). But we can't guarantee it; we prefer that our UPSes accept generator power rather than going to battery.

I think getting a generator that can produce more power is a safer option.

[voidstar_apc]

Hi Nik,

>
Will the ACP BR1500G-IN 1.5 KVA UPS keep drawing 30 watts of power from the generator and continue charging, while it is being loaded by a workstation drawing 750 watts of power?
>

When the UPS runs on generator, the total draw from the generator will be, at most, 30W (UPS) + 750W (Computer) = 780 W. That's more than the 400W provided for your apartment, but it's also a worse case. You'd have to measure the computer's actual power consumption to see if you can get under the 400W limit.

[Anonymous user · Accepted solution]

Thank you for clearing this up.

This would mean that I cannot run the workstation on an UPS. Though the actually power consumption may be less than 750w, it certainly cannot go below 400w.

Thanks again for your help