10 kVA Eaton UPS Teardown – Model PowerWare 9355

Test and teardown of a Eaton 9355 UPS (formerly the Powerware 9355). It is a three-phase, double-conversion online UPS. Output power ranges from 10-15 kVA in a changeover scenario as follows: 150% for 5 sec / 125% for 1 min (online), 110% for 10 min. Battery type is 9 Ah, sealed, lead-acid, maintenance-free. Battery charger is default 3.4A per battery string. Charger current is configurable from 0.5A to 25A per string with an overall maximum of 34A (limited by input current)

60 kVA Eaton PowerWare UPS Teardown: https://www.youtube.com/watch?v=DEqbqmqB7Rs
30 kVA Eaton PowerWare UPS Teardown: https://www.youtube.com/watch?v=8efFFIwhKuA
20 kVA Eaton PowerWare UPS Teardown: https://www.youtube.com/watch?v=UILLbEnZ4QU

The above teardown videos can also be found as full articles, along many other types of UPS or power electronics teardowns, in the complete list of teardowns I have performed.

Eaton 9355 UPS

I only brought home the top part of the system, as the inverter alone weighs 55 kg. From the marking plate at the back, its shown to use between 20 to 64 9Ah sealed lead batteries. Input/Output and Bypass 400V 50Hz 17A. Battery link DC 384V 9aH 36A. Nominal output power is 12 kVA or 10.8 kW.

The inside electronics is split into 4 major parts. A large PCB in the right side with all input and output filtering, the PFC frontend and battery charger. On top a controller PCB. In the back a large and very heavy output choke inductor. In the left side is the output inverter PCB with 3 skiip IGBT modules.

The Semikron SKiip 37AC125V20 modules are obsolete, with a date code from 2010, its actually hard to believe that a datasheet can not be located. It could be that its a custom part for Eaton, and the similar Semikron SKiip 37AC126 datasheet is the only one that can be found.

The controller PCB is split into a digital and analog section, sitting on each their side of the Texas Instruments TMS320 controller.