Dive Compressor on a Cruising Boat

[Zanshin]

Originally Posted by teneicm

Glad you brought this up again. We're about to install a Bauer Jr on the boat and are concerned that the 5 KW genset may not be up to the task of running the compressor. The concern is the inrush current, which can be about 3x the normal operating load. So even if the 3 HP Bauer pulls only 12 amps running, the inrush may be nearly 40 amps which could bog down the generator.

Anyone care to share the size of their genset that's running their Bauer Jr?

Thanks- Matt

Back when I had a Fischer Panda 5KW genset I spoke with both Bauer and Fischer Panda in Germany and their statement was it would be sufficient assuming the genset had the Fischer-Panda soft-start system installed or (what I had installed) a Victron Charger/Inverter system; both of which would help absorb the startup voltage spikes. With just a 5kW compressor neither manufacturer recommend an installation.

I now have an 11Kw unit, so am not even close to peak loads.

[teneicm]

Quick update here: Just installed a Bauer Jr II on the boat. Was worried about the capability of the 5kw generator to handle the startup spike, so we wired in a Lenze Frequency drive just in front of the compressor. The freq drive slowly starts the compressor by ramping up the hertz from 0 to 60 over 10 seconds. This elimates the start up spike. The unit costs about $500, but everything seems to work, so well worth the added cost!

[rcontrera]

Those are great. We use something similar to run our three phase compressor on single phase gensets.

Just be aware that you are at the top of your capability and that, at pressure, the compressor will be drawing a bunch of power. If you have additional stuff turn on, or the gen set has a hiccup and slows, the voltage may drop and that will drive up the amperage possibly burning out any electronics you have turned on.

So ... when you have the compressor running, turn off everything else.


Oh, and don't forget to change oil and filters regularly on your compressor and it should last you a LONG time!

[DivingOtter]

Hope you have proper in line filters on it.

[teneicm]

Originally Posted by DivingOtter

Hope you have proper in line filters on it.

Could you please elaborate? In line filters for what? Electric or air or ??

[Bash]

Originally Posted by teneicm

Could you please elaborate? In line filters for what? Electric or air or ??

Carbon monoxide, among other things. http://thedecostop.com/forums/showth...and-Filtration

[rcontrera]

I think you will find that modern US commercially available breathing air compressors come with adequate filtration. The standard outlet filters have a drying agent, a carbon monoxide scrubber and a scrubber to remove taste and odor.

[teneicm]

Air filtration is all good. I thought DivingOtter may have meant something to do with a "line filter" for the electrical connection to prevent the Frequency drive from sending interference back to the generator. There was some talk of this being a possibility, but the advice we got was to not worry about it unless we saw issues with the generator.

[lorenzo b]

General consensus among divers in the Roatan area is that it's a lot easier to carry 10 extra tanks and fill at a dive shop than deal with a compressor on board. If you dive three times a day every day or dive far from dive shops that may not be true.

[DivingOtter]

sorry, should have elaborated more.. The inline filters will produce a clean breathing air and remove toxins, as well as having moisture separators that you can blow down that will prevent moisture from being transfered into your tanks. Im not a fan of scuba and never will do it again, I do all surface supplied hard hat and last time I dove scuba I ran way too low on air as im used to not having to worry about that with compressors or HP air banks. My fault for letting it happen but I wasnt paying attention, but these days I dont dive unless im being paid.

[downunder]

Diving Otter is talking about surface supply/Hookah not SCUBA.

[DivingOtter]

Originally Posted by downunder

Diving Otter is talking about surface supply/Hookah not SCUBA.

Even if your filling scuba tanks you should still make sure it is clean air. Thats where the in line filters come into play.

[downunder]

Originally Posted by DivingOtter

Even if your filling scuba tanks you should still make sure it is clean air. Thats where the in line filters come into play.

As rcontrera said all descent scuba compressors such as Bauer have quality purpose designed in line filtration built in as part of the compressor.

[DivingOtter]

Those filters still need to be replaced. I know the 3 that I have on my compressor cost 250 a pop.

[rcontrera]

Very good point Otter!

I have had customers in the past that never bothered to read my instructions or the owner's manual and would cll me to complain that their air tasted bad. When I would ask them how many hours they had on their filter cartridge, you could almost hear them tilt their head and look at the phone like a dog that is hearing a strange sound.

The filters that come with the little Bauer or Coltri compressors are only good for about 3000 cubic feet of air, which is about 40 standard scuba tank fills. And those filter cartridges are about $40-50.

Typical boat installations are quite a bit different from your commercial diving filters in design and cost. But the same basic philosophy ... only breathe clean dry safe air underwater and you will most likly come back up at the end of the dive.