Wednesday, January 11, 2012

A Good Day

AC Grounds:  I solved a complicated puzzle related to my AC yacht wiring.  It was complicated in that the manufacturer of my isolation transformers provided an improper circuit diagram to wire them in leaving the AC floating instead of bonded. 

I spent hours testing different portions of various circuits without any success over the last few days.  Yesterday, after a fruitless day of troubleshooting, while getting into my car I realized out what was wrong.  Bonding the neutral wire to ground at the source---each of the isolation transformers--similar to what is done a the main panel in a house.  I rushed home and looked it up on the internet and found that 95% of the manufacturer recommend this method, while only a few--my manufacturer, did not. 

So today I bonded the ground and neutral wires at the isolation transformers and that stopped the potential between neutral and ground throughout my AC circuits.  This provides a safe grounding circuit to prevent electrical shocks, but also increases the change for galvanic corrosion to a small degree.  I do not expect any major change in zinc erosion.

I spent the day cleaning up the back of my AC panel, relocating and testing indicator lights for my shore feeds which I modified this week to serve two shore power inputs simultaneously, instead of an either or switch, and of course, grounding each isolation transformer.  Voila, everything tests out perfectly.

Then I checked each ground wire and made sure each circuit included a ground wire that went back to the AC Ground Bus, and I also upgraded some these connections to heavier wire.  For example the inverter to ground bus is a 6 gauge wire, and the final step tomorrow is installing a 6 gauge wire from the AC bus to ships ground--then all the AC grounds are done.  The wire and the terminations are purchased and ready to install.

LINK 1000:  Still to do is hooking up the battery status meter, a LINK 1000 which measures how many Amp-Hours go in and out of my 400 A-H battery bank.  That will take a while to hook up and program.  It has 8 wires plus a second 8 wire cable which is pre-made but needs to be shortened.  My printer is down so I need to load the PDF on my laptop and bring that down instead of printing it all out.

Battery Temperature Sensor:  I also discovered my battery temperature probe is bad. I think I can get the manufacturer to send me a new one given all the problems I've had with this charger.  How do you tell if a sensor is bad?  It will generally read a higher voltage (think it is cold) than should.  If you unplug it and the voltage drops, it is bad.  Mine was reading 13.8 volts for AGM batteries.  That might have been ok, if the temperature was below or close to freezing.  It was more like mid-fifties or higher inside...so it was bad.  Unplugged is not a problem as 13.5 volts is fine until I can replace it.  Also, it is better to put the temperature sensor on the + terminal on the battery, but it can go anywhere, the negative side or the side of the case.  Attaching to a battery terminal generally give a more accurate reading. 

DC Wiring Projects:  While at West Marine today, I bought new bow lights to go with a stern light I bought last year.  I would like to start to wire those into the DC panel, which will really dress up the looks of the boat and allow me to legally take the boat out at night while under power.  My Tricolor is working but that is prohibited with a steaming light.  I will need to pull some wire and also fabricate mounts for these three lights.  This is a project that sounds easier than it is.  I will need more wire, mounting shims for the bowlights, and a bracket for the stern light.  Pulling wire inside of the stainless tubing is the neat way to do it.  I will also need to buy a steaming light and think about mounting that on the mast and running wire down the mast.  I won't being doing any of this all that soon, and I expect to break this task up in to smaller chunks. 

More important and much easier, is pulling wire forward and installing a sub panel in the forward locker to serve the V-berth, Forward Head, and closet lighting and fans.  I will do that in the next few days so I can mount a few night lights in the V-berth and in the forward head--things I badly need right now as I will be working in that area soon.

Binnacle Refurbishment:   I priced out the cost to refurbish my Compass.  Mine is crazed and missing the lamp.  I hate compasses without lamps.  I have suffered through using flashlights and those are painful to use and cause compass error.  Unfortunately, the cost to refurbish my SP5 Globemaster is $210--a bit pricey, but it is important to me.  Another option is to simply replace the lamp--$20.  I lean towards making the compass look like new.

Another thing I need is new instrument mounting brackets and a housing for a chart display--even more pricey, but worth doing.  These are all things I will need but defer on purchasing until next month.  So I would like to have the parts list ready to go, so I can order it all at once and time it to do the entire job at one time.  My goal is to have a 12" Simrad Chart Display with a 4G radar, and relocate my RayMarine SeaTalk instruments to a four across pod.  I will need an offset rail to mount all this, and that means new feet and a new bracket too, since the tubing is now 1-1/8" up from the original 1" tubing.  I'd like to have a table and a cockpit light installed later on. The table is simple to bolt to the rail. And the cockpit light I'll mount on the pushpit.