[PSUBS-MAILIST] Ammeter Question

Wed Jan 10 12:33:00 EST 2018

Brian, here is a link that describes it pretty good (better than I could). You have to match a shunt to a meter if there are not already a package deal.
https://www.homepower.com/whats-shunt

I am designing for 300A fuses on the positive posts of ea. battery. This is based on my total max. electrical load being calculated at 250A. I can't image the scenario where every load will be energized and drawing max. current at the same time but this is the worse case load potential. I do not see any potential "start up" loads that will result in exceeding these ratings.

I also will have a 300A breaker as close to the batteries as possible.  These individual battery fuses are an ABS guide line I believe. It just makes me feel better knowing I have protection as close to the batteries as I can get (on the + posts is very close).  I think the likelihood of having a short between the batteries and my main breaker is small (secure installation, short cable lengths etc.).

Right now I am double checking loads (some are estimated (worse case))and then determining required ratings (breakers, fuses, wire and buss bar sizes etc.) before ordering materials. I will upload my working drawing when I am done to my projects page.  They mainly show the planned circuit devices, wire and protection device values. I am oversizing everything a bit.

Thanks,
Steve

---- Brian Cox via Personal_Submersibles <personal_submersibles at psubs.org> wrote: 
> Steve,   What does that in line shunt do?        What amperage fuses are you using at your battery terminals?  Are you worried about start up voltage blowing the fuse?

Brian

--- personal_submersibles at psubs.org wrote:

From: Steve McQueen via Personal_Submersibles <personal_submersibles at psubs.org>
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Subject: Re: [PSUBS-MAILIST] Ammeter Question
Date: Wed, 10 Jan 2018 8:25:57 -0500

Yes my K-250 is a 12V DC system.

FYI, In the diagram I sent I have decided I will also be adding battery terminal fuses directly on each of the positive battery posts (the diagram does not currently reflect that).

They also make "in-line" shunts that you then use as ammeter sensors. I have attached an image. 

Thanks,
Steve

---- Rick Patton via Personal_Submersibles <personal_submersibles at psubs.org> wrote: 
> Steve,
> 
> Thanks for the attachments and input. Are your thrustors 12V? On my 350, my
> 12v system just runs the instruments so the draw on the 12v should be
> pretty low but on my 36v side I will need a much larger amp meter as my 3
> thrusters at max will be 140 amps but I am also running 6 external LED
> lights off that bank as well @ about 2.75 amps per lite.
> Rick
> 
> On Tue, Jan 9, 2018 at 3:17 PM, Steve McQueen via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
> 
> > Rick, I am making the same decision currently.  I am leaning toward using
> > a 300A ammeter to monitor total current draw in my 12V DC system (see
> > attached example and working sketch).
> >
> > I am going to use the “circular loop” style tap (hall effect sensor)
> > mainly because the point I am monitoring is 2/0 AWG.  Not an easy thing to
> > splice into.
> >
> >
> >
> > There might be some sensitivity/accuracy issues associated with the exact
> > location of the wire within the sensor but I not concerned with high
> > accuracy as much as a repeatable reference. I would guess you could
> > arrange/install it such as to minimize this positional concern.
> >
> > I am not sure about the sensor being affected by “touching” the hull but I
> > would just mount it such that it avoids that contact.
> >
> >
> >
> > Personally I am not monitoring individual thruster circuits but am relying
> > on breakers to indicate issues.
> >
> >
> >
> > I am trying to keep things simple in my K-250.
> >
> >
> >
> > Steve
> >
> >
> >
> > *From:* Personal_Submersibles [mailto:personal_submersibles-
> > bounces at psubs.org] *On Behalf Of *Rick Patton via Personal_Submersibles
> > *Sent:* Tuesday, January 9, 2018 7:49 PM
> > *To:* Personal Submersibles General Discussion <
> > personal_submersibles at psubs.org>
> > *Subject:* Re: [PSUBS-MAILIST] At Home O2 Cleaning Process
> >
> >
> >
> > Can't get into my contacts page to send a new thread rite now (I hate
> > computers) so gonna tag this thread for something different, sorry...
> >
> >
> >
> > I am getting ready to purchase my amp and volt meters for the 12V and 36V
> > banks and had a few questions. There are two ways that I know of to tap
> > into a line to measure current. One is a direct splice and the other is
> > using a meter that has a DROK/necklace that encircles the wire you want to
> > measure. Would like to know the best way to go on those types. It would be
> > a lot easier to use a necklace type to minimize the amount of splices that
> > I have to make and moisture proof but a friend of mine said that there is a
> > minute difference in readings if the wire is up against the side of the
> > necklace rather than in the middle and I also wounder if having the
> > necklace up against the steel hull would mess with the readings?  I also
> > assume that I should have a separate amp meter for each of my three
> > thrusters?
> >
> > Thanks
> >
> > Rick
> >
> >
> >
> > On Mon, Jan 8, 2018 at 6:08 AM, Brian Cox via Personal_Submersibles <
> > personal_submersibles at psubs.org> wrote:
> >
> > Cliff,   I ordered those items !    I'm going to get another style flow
> > meter as well .  How accurate is that acrylic flow meter?
> >
> >
> >
> > Brian
> >
> >
> >
> >
> >
> > --- personal_submersibles at psubs.org wrote:
> >
> > From: Cliff Redus via Personal_Submersibles <personal_submersibles at psubs.
> > org>
> > To: Personal Submersibles General Discussion <personal_submersibles at psubs.
> > org>
> > Subject: Re: [PSUBS-MAILIST] At Home O2 Cleaning Process
> > Date: Sun, 7 Jan 2018 14:21:18 -0600
> >
> > Brian, in my (Air Monitoring, Oxygen Control) AMOC system, I use a Porter
> > 201-FSVP mass controller.  Ebay has these units for sell all the time at
> > pennies on the dollar. These unit will both measure the mass rate of the
> > gas in SLPM and also control it. There are two 0-5VDC control signals for
> > the unit.  For this partuclar unit which has a 0-10 SLPM span, if you give
> > the controller pin 5V, then it will pass 10 SLPM if you give it 0V, it will
> > pass zero SLPM.  The other singal is an analog voltage output signal again
> > 5Vdc for full span, would be a measured 10 SLPM and a zero signal means it
> > is reading zero mass flowrate of gas.  https://www.ebay.com/itm/
> > Porter-201-AFASVPAA-Mass-Flow-Controller-10-SLPM-760-Torr-
> > MFC/232159305887?hash=item360dc5e09f:g:BTAAAOSwmrlUrcG1 is a link to ebay
> > for a unit very close to this.  Porter (Parker) make a ton of different
> > controller for different rates and different gasses.  The controller as a 9
> > pin blade style connector that is used widely in the medical industry.  The
> > documentation on these meters is excellent and you can download it
> > https://www.parker.com/literature/MFM%20&%20MFC%20(D-
> > Conn.)%20(FM-898%20Rev.%20E).pdf .  The manual calls out the spec for the
> > connector.  I use this unit with a PLC but single it is analog voltage
> > signals, you could control with potentiometer off a 5VDC source.  Likewise
> > you could use an analog display that would take a 0-5VDC signal if you
> > wanted. I have found these units to be very reliable.  In my Life support
> > system module, I use a Swagelok a Vernier needle valve model SS-SS4-VH as
> > a bypass around this controller for manual O2 bleed control.  As a backup,
> > I use a variable area meter like https://www.amazon.com/dp/
> > B019YS4PSG/ref=asc_df_B019YS4PSG5328541/?tag=hyprod-20&creative=395033&
> > creativeASIN=B019YS4PSG&linkCode=df0&hvadid=198097951144&hvpos=1o1&hvnetw=
> > g&hvrand=6957636125906653374&hvpone=&hvptwo=&hvqmt=&hvdev=
> > c&hvdvcmdl=&hvlocint=&hvlocphy=9027968&hvtargid=pla-542207540152 .
> >
> >
> >
> > Cliff
> >
> >
> >
> > On Sat, Jan 6, 2018 at 1:56 PM, Brian Cox via Personal_Submersibles <
> > personal_submersibles at psubs.org> wrote:
> >
> > I just talked to my local dive shop and they will fill O2 no questions
> > asked .  They say they do it all the time.  I'm thinking of getting set up
> > with a package from DAN  Here:
> >
> >
> >
> >
> >
> > https://www.diversalertnetwork.org/dive-store/?catno=9
> >
> >
> >
> >
> >
> > It seems to be somewhat problematic getting the right all the components
> > but getting one of these units from the DAN website might make things
> > easier as far as getting bottles filled and so forth.  The delivery system
> > on these units I don't think has enough fine tuning ability however.  Does
> > anyone have a good flow meter to recommend?  Is there an analog type with a
> > little ball that floats up and down?
> >
> >
> >
> >
> >
> >
> > Brian
> >
> >
> >
> >
> >
> > --- personal_submersibles at psubs.org wrote:
> >
> > From: "Sean T. Stevenson via Personal_Submersibles" <
> > personal_submersibles at psubs.org>
> > To: personal_submersibles at psubs.org
> > Subject: Re: [PSUBS-MAILIST] At Home O2 Cleaning Process
> > Date: Sat, 06 Jan 2018 13:58:20 -0500
> >
> > I use dilute acetic acid to remove any existing corrosion, and then a
> > non-solvent hydrocarbon-free detergent solution to clean, followed by a
> > freshwater rinse, and possibly another cycle using a separate clean batch
> > of detergent solution. Use dedicated brushes for each bin. A lint-free
> > cloth should come back clean, and the cleaner solution and rinse water
> > should both produce no fluorescence under UV (black light). Dry passively,
> > or with filtered air or bottled nitrogen so as not to reintroduce any
> > contaminants. Any subsequent lubrication or assembly with lubricated soft
> > parts should be done with oxygen compatible lubricants (i.e. Christolube).
> >
> > Sean
> >
> > Sent from ProtonMail mobile
> >
> >
> >
> > -------- Original Message --------
> > On Jan 6, 2018, 09:23, Steve McQueen via Personal_Submersibles <
> > personal_submersibles at psubs.org> wrote:
> >
> >
> >
> > All, I am working on cleaning some parts/pieces for O2 service on my
> > K-250. I am buying most items “pre-cleaned” such as: Tank w/Valve, First
> > Stage Regulator, Thru Hull Isolation Valve, Flow Regulator.
> >
> >
> >
> > However, I will have some parts & pieces (mainly misc. adaptors and ¼ SS
> > tubing) I may still need to clean.
> >
> > I know an “at home” process will fall short but looking to create/document
> > a procedure anyway.
> >
> > ·        I am using ASTM G93, "Standard Practice for Cleaning Methods and
> > Cleanliness Levels for Material and Equipment Used in Oxygen-Enriched
> > Environments" as the standard.
> >
> > ·
> >
> > ·        Maybe someone already has a procedure (or opinion) they want to
> > share?
> >
> > Steve
> >
> >
> >
> > ·
> >
> >
> >
> > ·        I am using ASTM G93, "Standard Practice for Cleaning Methods and
> > Cleanliness Levels for Material and Equipment Used in Oxygen-Enriched
> > Environments" as the standard.  I know an “at home” process will fall short
> > but looking to create/document a procedure anyway.
> >
> > ·
> >
> >
> >
> > _______________________________________________ Personal_Submersibles
> > mailing list Personal_Submersibles at psubs.org
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> >
> >
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> >
> >
> > _______________________________________________ Personal_Submersibles
> > mailing list Personal_Submersibles at psubs.org
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> >
> >
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> >
> >
> >
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> >
> >

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