Uninterrupted power supply (UPS) for different countries?

[bhl777]

Hi All,

I want to find out an off-the-shelf UPS that can support both 120V/50Hz in the US and 230V/50Hz in EU for computers. However, I have some questions.

My understanding is:
(1) for most of the offline/standby UPS, this is not possible, since we have a direct path from AC input to the AC output.
(2) for online/double conversion UPS, theoretically it is possible, because
- (a) at the input side, we can use the circuits to deal with world voltage and charge the battery
- (b) at the output side, if some product provides the programming capability, the users can set the ac line voltage and frequency to fit with their own countries/regions.

My questions are:
1. is the understanding (1) above correct? if so and I assume most of the UPS for computers is offline/standby UPS, can I say most of the UPS products in the market cannot be used in both US and EU?
3. is the understanding (2) above correct? If so and anyone knows such a product online, would you point me to it?

Thank you!

 

[wwfeldman]

look at this

2320270 Phoenix Contact | Line Protection, Distribution, Backups | DigiKey

Order Phoenix Contact 2320270 (277-2529-ND) at DigiKey. Check stock and pricing, view product specifications, and order online.

www.digikey.com

i did not look up all of the specifications
nor did i try to answer your questions

at least on first look, it appears to do what you want

 

[Easy peasy]

direct path from AC input to the AC output.

the above does not prohibit 115 / 230 as Vin will = Vout

The inverter control can see the Vrms and the freq and match same, and step in when the mains falls out of spec, either at 115 or 230

why did you think it was an issue ?

--- Updated May 12, 2021 ---

p.s. the US is 60Hz ( not 50 ).

 

[bhl777]

look at this

2320270 Phoenix Contact | Line Protection, Distribution, Backups | DigiKey

Order Phoenix Contact 2320270 (277-2529-ND) at DigiKey. Check stock and pricing, view product specifications, and order online.

www.digikey.com

i did not look up all of the specifications
nor did i try to answer your questions

at least on first look, it appears to do what you want

Hi wwfeldman,
Yes, your suggestion works! This is the solution that can accommodate both US and EU. Just FYI, I found two disadvantages:
1. the price is very high. If we are comparing the US-only UPS in Amazon.com, this one is almost 20 times more expensive.
2. there are no standard connectors on it and we have to use bare wire to connect this UPS for both in and out.
I also searched for some other similar products, and it turns out the disadvantages above still be valid.

--- Updated May 13, 2021 ---

the above does not prohibit 115 / 230 as Vin will = Vout

The inverter control can see the Vrms and the freq and match same, and step in when the mains falls out of spec, either at 115 or 230

why did you think it was an issue ?

--- Updated May 12, 2021 ---

p.s. the US is 60Hz ( not 50 ).

Hi Easy peasy:
Thank you for pointing out my problem, for both 60Hz and my misunderstanding of the direct path.
You are right, the direct path is not an issue, and the key difference between a universal one and a US/EU-only UPS is the capability of the inverter.
Thank you for your advice!