The power consumption of the VS-640 during operation is 1080 W. (The VS-540 consumes 1050 Watts.) Using a 1500 VA (865 W) UPS for this printer is NOT a good solution! The UPS will be overloaded when the heaters are on!
On the USA market, an APC 1500 (865 W) UPS is about $199. For the SAME amount, we can purchase an Xfinity PRO 2000VA (1200W) UPS. That will work...