AC voltage down tether

[merbass]

So here's my plan for provding power to my ROV. There will be a large 12 volt marine battery topside. Power will then be converted to 120VAC with this unit, http://www.alliedelec.com/search/produc ... #tab=specs, sent down 250' of 18 gauge wire, then converted back to 12VDC with this unit, http://www.alliedelec.com/search/produc ... #tab=specs. I haven't decided which thrusters yet, but there will be 4, (2 horizontal and 2 vertical), and I'd like to keep the current draw to 10 amps each. With this setup, I shouldn't have to worry about voltage drop, and i should have enough power for the thrusters. My question is, are there any special considerations I should be taking into account with regards to running 120VAC down to the rov, i.e. grounding? Safety? Has anyone used a similiar set-up? Thanks!

[KR2_Diving]

assuming the marine battery sets you back another $80-100, thats close to $500 just on your power system! any reason you are not considering onboard power? you can get a few relly good batteries for that kind of money, and save the hassle (read danger) of running AC power in or around the water...

if however you already have all those parts... i would say proper grounding is a must, and make sure the wire you use as a teather has durable insulation, you would hate to be realing in your teather only to discover a puncture the hard way... zap!

.(as a side note, what kind of heat is that AC to DC converter going to produce...)

[jeff]

Personly I'de stay well away fron AC and use onboar power, or upreate fron 12 to 24v shore power and check your volt drop at sub end. If needed you could use a volt dropper as the rov end. whatever volts you use shore side you can always bring it down at the rov, AC is dodgey stuff wth water, here in the uk we have 250vac. I would not want to go down that road, Stay safe my friend,JEFF