Hi @imhififan
hope it works with the pics:
(link Icloud: https://www.icloud.com/iclouddrive/04bYXYU4boecaHce1E39q0HMA#Voltage)
(link dropbox:
)
My guessing:
DP900: just change the two black wires with the two brown wires.
DC901: As you said only change the jumper from J1 to J3
What do you think man:-)
I have manual of the DP800/DC801 looks bit similar.