Note that AC power system voltage drifts all over the plane normally due to ordinary changing demands. So saying "it's 245V" - it may be 239V or 247V in another minute when an A/C unit cycles on or off or the town's aluminum smelter starts a batch. This is normal for AC power, and everything is built to tolerate it.
This is a serious case of miscommunication
Assuming this is bona-fide HP product, it will be certified to domestic safety standards for the market it's sold in, e.g. UL in the United States. Part and parcel of those safety and quality standards is the voltage tolerance on the AC supply. The standard requires them to tolerate the entire range of electrical voltages which power companies are permitted to supply, minus some more for voltage drop within a site.
Not optional. You will not get a UL/CSA/BSI listing without proving that.
Therefore whoever told you that you couldn't exceed 240.0 volts is simply incorrect. Or the product is a fake LOL.
If they're legit, what they surely mean is "Do Not Connect This To 277 Volts", which is "the next voltage up" in the North American spectrum. (it's one leg of 480V/3-phase, which is why it's a funny number).
That 220V "thing"
When Edison started out with DC power, it was a nice round 100V/200V. However Edison wanted to increase the voltage to increase system capacity, so several "voltage bumps" were planned. Edison had light bulb makers make light bulbs for 105V. Then after a few months Edison bumped system voltage to 105V/210V. Then had light bulb makers make 110V bulbs, and bumped system voltage to 110V/220V.
And that's when Edison lost the "War of the Currents" and Westinghouse took over all the legacy Edison systems. The year is 1892.
AC made it possible to sell power to the masses, so a huge publicity campaign ran, promoting "110 / 220 volts". It is now a fixture of popular culture, and that is why you call it "220V" informally.
That is wrong. Since 1892, power companies did three more bumps, now putting us at 120/240V "officially" but leaning toward 125/250V with the tolerances mentioned in the earlier link.
Further, EU is 230 volts -10/+6% (207V-244V).
UK and Australia are 230V +10/-6% (216V-253V).
So clearly, the salesman who told you the voltage spec is very confused. I would talk to someone knowledgeable.
If they indeed can't tolerate more than 240.0 volts, demand they put that in writing. That will force the person claiming it to actually check their facts.