I have two server PSUs from HP which can output 12V with 1200W (HP DPS 1200.) My goal is to obtain 24V by chaining the outputs of the two units.
I have modified one of the PSUs so that the negative output is no longer connected to earth by replacing one of the case screws with a nylon one, as recommended by threads in RC forums, where users use those supplies to power their battery chargers.
The metal case of both supplies is still grounded, so the only concern should be high voltages on the 24V output of the combined unit if something goes wrong inside the PSU.
One guy in these forums was concerned about the over voltage protection no longer working if this modification is done.
I want to know if such a modification disables safety features in events where the transformer is defective and shorts mains voltage to the low voltage side and if the order in which the supplies get connected changes this behavior.
(negative/earth side of the unmodified unit to 12v of the floating unit)