sorry guys, the electrician is ansolutely correct
setting up data rooms over the last 40 years, we have had this problem several times
most recently with a good client's tennant
we often laugh about how a client expects us to "lower the town's voltage"
(AND YES, THE DIFFERENCE BETWEEN 240 VDC & 245 VDC IS MINOR)
in an industrial setting there is often a (large) stepdown transformer with multitaps & the adjustment is made by moving one wire
the tech at HP could probably be reassigned to a job with their capabilities
steenland, unless you live on the most perfect power grid in existence, if you like i will loan you one of those old fashioned expanded scale line voltage monitors. and you can watch the needle bounce for a week or two. after a few days, you will wonder how any of our equipment survives the day to day fluctuations we all have
we often have to document this with a strip chart recorder (very old school) or a meter that connects to a laptop & saves a file before we "get our way" in disputes withn a manufacturer
that being said, i hope hp can rethink their answer (being hp it isn't always in their nature)