One of the inportant things to remember is that Robertson/Simrad dosent make pumps or rams. If you look at a Comnav, Robertson, Simrad, Autohelm
ect pump you will notice that they are all the same. There are typically two sizes that are matched to the ram size and vessel weight. Robertson/Simrad calls theirs the RPU 80 and RPU 160. Most rams are manufactured by Hytonics.
To answer your question, they just dont care. The pumps have a 3 wire control hookup from the junction box that sends a signal to the motor
to spin the pump clockwise or counterclockwise.
If you have more questions call Simrad. They use to be Robertson and I have found them very helpfull.
We have a 25 year old Robertson system that I have kept functioning by purchasing parts
off ebay. Its amazing how many of them their are out there. Ours now uses an AP200 control head
, a junction box origonaly from a AP25 system.
I have purchased two complete eletronics packages (for spares) piece by piece, never paying more than $ 30 for each.