Month: May 2015

Always check your ground……

When we encounter something on our boat, I realize that we generally aren’t reinventing the wheel here.  I mean, there here are certain axioms in any field that have stood the test of time and been proven over and over again.  One of these, in the field electronics is “Always check your ground first” ….ok, that might not be the literal way it is stated but you get my point.  Most electrical (and I think especially 12 volt systems can be pretty straight forward.

Let’s say you have a 12V source and a device that needs 12V power.  For this example, let’s say your device is a Chartplotter….now, this Chartplotter has worked flawlessly for about 12 months….but suddenly on the day you are scheduled to leave for a ten or twelve day trip, and it won’t turn on…..ugh

Here’s the thing about boat electronics, there is generally a fair amount of moisture in the air and that moisture can lead to corrosion on even the best protected (heat shrink wrapped, electrical taped and wire nutted) connections you can make.  When it does you will experience a failure that may leave you baffled.

In this instance, you begin troubleshooting and find that the device is indeed receiving well above the prescribed 12V (which is common in a 12V system as 12v is a nominal voltage for functionality).  I commonly see 12.7 to 13.0 in some of our circuits.  After a short period of testing a retesting the power, you try the device….it turns on and you feel like a genius….seconds later it flickers and dies….now is the time for that saying….check your ground.  The easiest way is to provide a direct link to the device from a known solid power source….and a very solid ground….a close battery or even a substitute 12V source.  I keep a cigarette style power plug in my 12V electrical kit that has the wire end cut off that I can direct wire to any device to test functionality.  That easily eliminates or confirms that the device is functioning as it should.  You may even see a steady current using an electrical or “fluke” meter.  Don’t be fooled by that into thinking your ground is solid.  Meters can be much more forgiving than a device that uses power. you may even get a good “continuity” signal from the meter.  Many boats have had many owners and some of these owners may not have been the best or most strict when it came to their wiring techniques.  A lot of people assume if it works once it will always work which is generally not the case.  Since our Chartplotter is such an important piece of gear (we get tide info, currents, calculate arrival times, read charts, obtain general information about any spot you can click on the touch screen and you can add information as you go along) it really becomes very, very useful.

The fastest and most reliable way to remedy this is to establish a new power and grounding bus bar ( In electrical power distribution, a busbar (also spelled bus bar, or sometimes as buss bar or bussbar, with the term bus being a contraction of the Latin omnibus, “for all”) is a metallic strip or bar (typically copper, brass or aluminium) that conducts electricity within a switchboard, distribution board, substation, battery bank, or other electrical apparatus. Its main purpose is to conduct a substantial current of electricity, and not to function as a structural member.) for the device.  Our grounding system needs a good cleaning and some minor rewiring but since we were on a tight timetable I opted for the new bus.  We wired the bus directly to one of our house battery banks and put a fuse on the positive line between the batteries and the bus bar in the event of a battery failure. There was also a fuse between the bus and the Chartplotter.  If your bus bar is in an area where things are crowded (and where on a boat aren’t things close) it’s probably a good idea to put a plastic or other non conductive cover across the connection points to avoid a short. This condition could cause a fire if it happens.  Even a 12v circuit can generate a tremendous amount of heat if the wires become damaged or another item capable of conducting the power comes in contact with both side simultaneously for long enough.  The best example of this is a screw that accidentally pierces both sides of a wire after being driven through a bulkhead and through  a concealed wire.

It helps sometimes to envision the device as a pass through for the current.  The power not only needs to get in but it also needs to get out and back to the battery for the device to work as it should. If all the power that goes in can’t get back out through a solid, consistent ground you will have an issue like we did.

Once we had a solid ground, the Chartplotter worked as it always has and we were ready to depart……I hope you will also be ready if you encounter this circumstance…..check the ground !!

 

Socks can kill and sweat can be a dangerous lubricant ….or…ouch, that hurt

It’s funny how the human mind works…..you get into a habit or routine and it becomes second nature, it can be almost comforting to engage in sometimes meaningless practices.  Then there are those that exact a price when you forget them or neglect to make them consistent.  Take socks for instance, innocuous enough, right? Well, I learned the hard way once, after what must have looked like a tumultuous sledless sled ride, a scene from Home Alone, or a half hearted attempt to break my tailbone, that bare socks can be a dangerous set of footwear on a boat.  I think the exception being those “treaded”, rubbery socks like they issue at the emergency room, which is ironic since the other kind can send you there.   Recently, when returning to Kitty Hawk after about a month away, I kicked off my offensive “street shoes” on the dock (mistake #1) and hopped aboard to get things turned on and ready for my stay leaving my socks on (mistake #2).  Well, one step into the forward companionway and “swoosh” went that leading sock clad foot….down into the salon..the left foot decided to stay in the cockpit…….fortunately, for me, I have this other, more ingrained habit of holding onto the lip of the hatch with at least one hand as I descend the stairs….that saved  me….granted I was doing the most awful, uncomfortable airborne versions of the splits with my right hand on the hatch and my left hand wrapped around the side of the opening (which tore most of the skin off my ring finger knuckle….ow) .but that beat a broken ankle or a concussion……..I initially learned this sock lesson the very hard way by breaking my pinky toe while wearing socks on deck about 18 months ago….that took months to heal so you’d think it would have made a more lasting impression, but no.

Yesterday, I almost repeated what I like to refer to as another  “lack of friction” incident while working on our house water pressure pump. The pump had decided shortly after my first shower to stop supplying water pressure despite running at full speed.   Ours is mounted on the forward bulkhead of the engine room and basically inline with the center of the diesel….so, not overly convenient to reach or remove.  It had been a long 5 or 6 hours in the engine room, it was about 85 outside and about 95 in the engine room.. I was drenched in sweat…..I think we, as a species, take the lubricating effects of sweat for granted.  I’m convinced that this solution, especially when mixed with any combination of fluids or sludge from the bilge, could easily be used to slide an elephant uphill while said elephant was seated on sandpaper. As I was trying to extricate myself from a pose that would have impressed any seasoned Yogi, I opted to wipe my hands (and other sweat laden extremities) off after I exited the engine room…bad idea….I had a rag right there….I had taken it into the engine room expressly for that purpose……… I knew I was a sweaty slick mess just looking for a place to have an accident….but I forged ahead….eager to end the pretzel torture of the engine room……slipping off the edge of the diesel where I was pushing myself upward, I nearly lost some teeth as my slicker than snot left hand lost contact with the edge of the diesel and my right hand was full of tools…..the only thing that saved me was the angle at which my leg was wedged between the diesel and the bulkhead….lucky but somewhat painful.

The troubleshooting, removing and reinstalling the rebuilt water pump was an exercise in patience and self control that ultimately ended in success …..I’d like to express my gratitude to Mike at American Pump in Melbourne, Florida for a very affordable and quick (four hour turnaround) on rebuilding the pump for me…..apparently, it’s a pretty simple thing but I had a LOT of other projects to complete in a short time for our pending departure North to NC. Mike was also kind enough to answer after hours troubleshooting advice via text message.  So, a big thumbs up to American Pump (321-724-2972) if you’re in the area and need quick, reliable service on a rebuildable pump!!!

Here’s my advice on house pressure water pumps…..if you hook it up, it runs, you have sufficient water in your tanks,  and you can’t find any air in the system or a leak that would prevent pressure from building ?  Let it sit overnight or for a few hours and then turn it on again…..apparently, the pump may take some time to allow the pressure from your tanks to displace the air inside the pump that it cannot remove itself with the self priming feature.  That two or three hours of tracing lines looking for leaks could have been better spent…..say, trying to catch a snook for dinner…!!