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I like the idea of a christmas tree display...even if only a single light. David Bartsch > Subject: Re: [PSUBS-MAILIST] Barometers > From: MerlinSub@t-online.de > To: personal_submersibles@psubs.org > Date: Wed, 29 Dec 2010 22:59:00 +0000 > > Cliff, you have a alarm for "hatch open" during diving in this small sub??? > > That is something I have not. Just high level water alarm in the bilge. > Works also fine as indirect "hatch is still open" indicator.. > But the full automatic hatch shower is also a good indicator.. > > smile.. > > vbr Carsten -by the way many subs sunk because a hatch was still open or not real close- > > > "Cliff Redus" <cliffordredus@sbcglobal.net> schrieb: > > Like Sg. Peppers, the R300 is a small boat. In early years I to had some pesky > O2 and air leaks which I eventully sorted out. Initially I tried to control my > O2 makeup valve using the measured cabin pressure with a barometer (700 to 1100 > mBar). I found this quite problematic. I changed to controlling off the O2 > concentration measurement rather than cabin pressure. This worked a lot better > for me. When the O2 level drops below 18% the PLC opened the O2 makeup solenoid > valve until the O2 concentration reaches 23% then it cuts off. It takes about 1 > minute for the O2 makeup value to cycle from closed to open to closed. In > additon to the automatic O2 makeup system, I have a backup manual metering > needle valve with a simple direct reading medical flow rate gage. I added a > cabin pressure gage that is 0-30 psia that I use to trigger overpressure > alarms. I had this alarm sound on one dive when a hair line crack developed in > O2 regulator high pressure fitting. The high O2 alarm also went off. At that > point I surfaced the boat. After blowing my MBTs, I began relasing my hatch > latches. After releasing the first one, the other released poping the > hatch open to releave the 5 psi overpressure in the boat. This sudden release > of cabin air was enough to unseat my hatch o-ring. I was very nervous for about > a minute until I reseated this o-ring as I could not close the hatch and my > freeboard is quite small. Needles to say, my diving was over for the day and I > did not dive the boat again until I found and fixed the source for the high > pressure leak and installed a hull equlization valve for the hatch. I also have > a high CO2 alarm which triggers when the CO2 partical pressure exceeds 5000ppm > (0.5%). This happens when the CO2 absorbent becomes saturated. Normal air has > about 300 ppm of CO2. I did quite a few 4-8 hour "garage" dives to make sure > the environmental controls were working and to sort out the CO2 scrubber fan > size. Acturally they are a lot of fun but a bit boring. Garage dives are a great > way to debug systems. The 15 alarms on the R300 are: > > High Oxygen Level, > 23% > Low Oxygen Level, < 18% > High CO2 Level, > 5000ppm > Hatch Open on Dive > High Main Current, > 300 Amps > High Aux Current, >20 Amps > Low pressure in Air Tank, <750 psia > Low pressure in O2 Tank, < 550 psia > Depth Exceeds 300 ft > Low Cabin pressure , < 12 psia > High Cabin pressure , > 20 psia > Motor field winding > 248 F > Seal Barrier Fluid Outlet Temp >200 F > Low Main Battery Voltage, <110Vdc > Low Aux Battery Voltage, <22Vdc > > Cliff > > > > > > ************************************************************************ > ************************************************************************ > ************************************************************************ > The personal submersibles mailing list complies with the US Federal > CAN-SPAM Act of 2003. Your email address appears in our database > because either you, or someone you know, requested you receive messages > from our organization. > > If you want to be removed from this mailing list simply click on the > link below or send a blank email message to: > removeme-personal_submersibles@psubs.org > > Removal of your email address from this mailing list occurs by an > automated process and should be complete within five minutes of > our server receiving your request. > > PSUBS.ORG > PO Box 53 > Weare, NH 03281 > 603-529-1100 > ************************************************************************ > ************************************************************************ > ************************************************************************ > |