Have a Qualification lab that has 50 Amp and 30 amp 3 phase outlets thru-out that are used to feed different CSZ ( Hot & Cold Chambers ) with flexible cord . Small chambers rated for 30 amp circuits and larger one 40 amps . We are adding on to this area and they want to make all outlets 50 amp 3 phase so any chamber can be plugged in anywhere . Can we just change the male plug on the smaller chambers to 50 amps ? Does the SO #10 cord have to be changed to ? Is this allowed ? The chambers have a fusible disconnect located on each side 30 amp for small ones , 60 amp for large ones .