Dive compressor on board

[diver dave]

We are hoping to close soon on a new to us boat. No generator on board, yet.

I've had a number of small dive compressors before, but not yet had to power one with an onboard genset.

So, I'm in the 4cfm size category, and considering a 3 or a 5 hp 240V version.
The genset I'm considering is a NexGen 9.5kW. Its small for its output, but will be a squeeze fit. But, even the NexGen apps person wasn't sure what size motor I could start with it.
The Alkin W31 is the series of compressor I'm considering. THis would be the only load, if the compressor is on.

Any real world experience out there ?

 

[JDCAVE]

Talk to OCDiver. He was in the dive charter business.

Jim

 

[psneeld]

The PO of my boat was a dive instructor with a compressor on board.

The boat has a 8KW genetic and he had a dedicated 30A 125V outlet to run his compressor.

Don't know if that helps but he would have a couple of students on board each week and spent months in the Bahamas.

 

[Lepke]

Ones I like the best is a compressor clutched to the engine. Fast tank filling. If you have a big boat, a tank farm.

 

[Ski in NC]

It is a crapshoot trying to figure out if a marine genset can start a big AC motor. Some motors take a LOT of surge to get up to rpm, and some gens are good at providing that surge, and some are rather poor. And some motors are easy to start.

I kinda like the idea of a belt driven compressor off a little dedicated engine, that way you don't have to go through the energy conversion steps of engine-gen-motor-compressor, it is just engine-compressor. You could also belt drive a smallish gennie off that same engine to run other loads.

Lots of ways to do this...

 

[skyhawk]

The only thing about that that gives me pause is mixing engine with breathing. I wanna make dang sure that no exhaust gasses or other fumes from an engine get anywhere near my breathing gas....ditto for oils mixing with O2 blends....

 

[diver dave]

Id really like a hydraulic set up from the little 30hp prime movers. Stb eng runs ships generator; port engine runs dive compressor.


Just two total engines on the boat. But, then two sets of hydraulics [emoji848]

 

[diver dave]

The only thing about that that gives me pause is mixing engine with breathing. I wanna make dang sure that no exhaust gasses or other fumes from an engine get anywhere near my breathing gas....ditto for oils mixing with O2 blends....

Upwind air intakes and hypcolite have worked well for me. It does require diligence. Portables are not hands off, especial when pushing O2 around and various CO sources on board.

 

[Lepke]

You can plumb the intake to the compressor just like any other plumbing. Put the intake somewhere upwind. I've been breathing dive air since the 1960s, mostly from engine driven compressors. I'm still here.

 

[Gabe n Em]

We've been dreaming of going down the same path. We don't really have the room on our current boat, but I'm interested to see where this thread goes, nonetheless.

Good luck in your search!

 

[Larry M]

We have 1.5 hp dive compressor that we use for cleaning the hull or changing zincs. We use our 2800 watt investor if the generators not on. No problem powering it.