OCPD sizing for a UPS

[JdoubleU]

How should I size my breaker for a 20KVA 3phase UPS? Do I just times that by 1.25?

 

[texie]

How should I size my breaker for a 20KVA 3phase UPS? Do I just times that by 1.25?

No.
As I mentioned in your other post, you need to provide more info. But this value is determined by the manufacturer as it has to include the battery charging current.
You need to be aware that UPS input and output wiring, OC protection, etc. are very specific for a UPS and the installation manual is critical information to follow. For example, some UPS are separately derived systems while others are not. This greatly influences a number of things in the installation.

 

[JdoubleU]

This information is not provided in the manual.

 

[zbang]

A call to tech support should get you the info, then. Otherwise, start with the ratings plate on it.

 

[Smart $]

How should I size my breaker for a 20KVA 3phase UPS? Do I just times that by 1.25?

You didn't state voltage, but it'd be at least 20kVA/voltage/sqrt3. A UPS is typically not a continuous load (it may be energized for more than 3 hours but typically does not operate at max rated current over 3 hours) so no factoring by 125% for continuous load is required.

 

[petersonra]

somewhere it will tell you the maximum input current in the manual or the nameplate.

if you are unable to find it there call the tech support line and ask.