Fridge trouble!

My Danfoss fridge compressor with Isotherm controls threw a fault and I found this on the controller and starter 

Bit of a worry!! I'll update once I get to the bottom of why the negative terminal has melted.

Found the problem.  Opened up the red controller to find the negative terminal broken off at the base (top spade terminal in photo...broken nearest to camera).  Shorting out.

Vibration over the years I assume

Update 2/6/21:

As usual I have spent an inordinate amount of time thinking about this problem, and I've become something more than a layman on the topic of marine refrigeration as a result.  I suppose these sort of challenges give me the opportunity to increase my knowledge base.

The solution to the problem begins with an explanation of how a marine fridge works.  The system is made up of at least 3 components:

1. The compressor - this is the metal canister from which the copper tubing carrying the refrigerant is carried to the 'icebox'.  They can be fan cooled or cooled by a water pump or a seawater/ self-pumping system integrated into a through hull (this is what Wireless has).

2. The control module - a device which controllers the compressor pump.  They receive inputs from the thermostat.  They can be DC only or AC/DC (more on this later...it is much larger).  The module is normally attached to the compressor.

3. The thermostat - this device varies from a simple mechanical dial that measures the icebox temperature and signals the control module to turn off and on as required, to a much more complex digital device that adds features like controlling compressor speed, durations, and monitors battery levels/charging.

So with a damaged module and a damaged ASU thermostat unit, I have elected to replace both.  Note the need to install a resistor in the feed from the thermostat to the module to control the compressor speed (the ASU units do this automatically but at a cost).  My self-pumping cooling system likes the compressor running at 3000rpm, so the resistor is selected to achieve this value (692ohm)

I will be installing the Elitech digital thermostat shown above.  This will be installed in the vertical face above and to the left of the hatch under the sink.  It will require a good sized cut-out, so I'll measure twice.  The unit is basic, without the Isotherm ASU battery-monitoring feature, but it's cheap, and has a nice display of fridge temperature (the ASU didn't).

This wiring diagram better describes how to configure a digital thermometer (which requires as 12v supply) into the system.  The lettering corresponds to the lettered terminals on the Danfoss module.

Update 17/6/21

So the module, Elitech thermostat and resistor have arrived.  I quickly realised the much larger AC/DC module could not be directly coupled to the compressor as was the previous unit.   The difference in size is significant,  2 5/8" deep versus 4 3/4".  I consulted with Sean at FridgeTech NZ and he has supplied me with an extension cable that will allow me to mount the module elsewhere under the galley sink.

Extension cable to mount module remotely

I will likely mount the module on the plywood wall that forms the starboard side of the drawer structure.  all of the wiring, both AC/DC and links to the thermostat will lead to this point.

Here are the connectors I use, all waterproof, self-sealing units:

Update:  Installation Day 1

While the DC power is already 'onsite' at the fridge, there is no AC power for the new AC/DC module.  I have a spare circuit breaker on the AC panel, whish was once used for the air conditioner (long ago removed).

I started with a 7m length of 3 core, 20amp cable, feeding it down under the sink floor.  I pulled up the floor, and ran the cable all the way aft to the engine panel adjacent the chart table.  The cable feeds through holes drilled in the ribs.

Once under the engine panel, the cable goes right, through the panel near the diesel filter, through the locker, through the bulkhead under the chart table, up and back into the electrical cabinet.  This is a pretty major undertaking.  I left the wire loose in the cabinet for now.

I also ran the new temperature probe from the sink locker into the fridge box itself, creating a passage through a small opening filled with expanding foam.  I will need to spray some foam back into this cavity once I have the wiring completed.

The digital controller was mounted on the cabinet face below and to the right of the sink.  This required covering an area with masking tape, tracing the outline of the controller with pencil, and cutting out the opening using a drill and a jigsaw.

Once the extension cable to connect the module to the compressor arrives, I will begin wiring up the entire system.  This will include the AC connections at both ends, the DC connection at the module, 2 set of wires from the module to the digital controller, and the temp probe (see diagram above).

If you're going to do a lot of wiring, get good crimpers and a wire stripper, and use the best quality connectors you can find.  I make sure to use a heat gun instead of a torch to seal the connectors.  The digital thermostat has the type of inputs that require the wire ends to be twisted and soldered.

Update:

The extension arrived,  and with a further 3hrs of wiring the fridge is quietly humming away.

It was not without problems as I discovered when I fired the system up for the first time only to be met with an E1 error messag.  This was certainly disappointing given the care I took when installing both the AC and DC wiring. In the end the solution was simple.

While I had been told that the temperature probe, a 2 wire cable, could be wired either way, this is not the case.  It only works if you get the wires the correct way round.  Trouble is you cant tell...  they are both black, and without markings.

If you are considering this setup, with a digital thermostat, make sure you have a jewellers flat head screwdriver...very small screws.

Fridge compressors like these are very quiet, so if you hear a noise or vibration, ensure the cooper tubes aren't touching. 

Exciting, I have a functional fridge again!

B&G 496/213 Masthead Repair

 My 15 year old B&G 213 masthead wind meter failed some time ago.  The directional indicator at the top is fine, but the cup speed indicator seems to have bad bearings.

Bearings required (2ea) are:

030804161

F1/8 x 5/16 x 9/64

FR2-5-ZZ

Inch Flanged Bearings

I'm pulling it apart and will replace the bearings.  First obstacle is a stripped 1.5mm set screw.

I'll try a few options before drilling it out, it will need replacing.

If I have to, I'll buy the entire bearing housing, which is $150NZD and is part # 213-10-038

These things are more than $1000 if you can find one, so worth trying.

Update 11/5/21:  I just ended up buying a new bearing for $169NZD.  I reassembled it and I'm just waiting for the rigger to re-install along with a new VHF antenna.

Update 2/6/21:  The rigger has installed the rebuilt wind unit, along with a new VHF antenna and in fact 2 new lenses and bulbs for my tri-color and steaming lights.  He also replaced my burgee line from the mast top.

New ship's clock!

Wireless has a matching Weems & Plath clock and barometer set.  Recently the clock failed, due to what I suspect to be a faulty plastic movement.

Trouble is...the bloody things sell for nearly $400NZD.  No replacement parts are available, even if I could find a way to work on it, as everything was glued together.  Even the battery was an oddball (try finding an N battery).

So I looked around an found a local alternative here in New Zealand.

Cruising Electronics

This is a business run by sailors for sailors and I'm happy to support them.

This is an outfit based in Cable Bay Northland that market various clocks, barometers etc.  I purchased the small version of the clock/tide clock combo.  Looking at it online I saw that it was obviously set in a brass case, with a traditional opening to ease battery replacement (the W&P required pulling it off the bulkhead).

I bought this clock for $155 NZD.  It arrived today and I was amazed.  It's heavy, as the case is thick polished brass.  The beveled glass face is also very thick, as are the hinges and "dog".  

Opening the case allows the entire clock to swing outward for easy battery changes.

I've now bought the matching barometer.

Deck Paint

 It's been a long time since I've updated the blog, due to a combination of available time, but also because the first few years of ownership were a flurry of renovations and improvements.  I had reached a point where Wireless didn't 'need' a lot.  I had addressed all of the 'must-haves' and life didn't allow for many 'want-to-haves'.

Well, the time has come to admit that the deck surfaces can no longer be rejuvenated with polish.  The gelcoat is dull and chalky, and more importantly, it has many spider cracks from becoming brittle under the New Zealand sun.  My 2014 deck project was focused on the teak work, re-bedding fittings, and a good surface polish. 

Spiders cracks evident around grab rails.

In preparation, I have gone over the deck identifying and fixing imperfections and the spider cracking.  To give the crack repairs a fighting chance, I enlarged them with a ball tip cutter on my Dremel tool.

This now gave me the ability to get some Epifill to stick.  This product is easy to mix and also sands easily.  Because it is epoxy-based, it sticks tenaciously and is water proof and durable.

I'm afraid I don't have before photos of the spider cracks, but you can imagine they radiated out from stress points like deck fittings, and particularly in the cockpit sole.  I'll take a battery of photos moving forward.

So the next step, now that I have sanded the Epifill, is to look for areas that may need a 2nd application.  After that I'll follow this process:

1. Select area to paint (I'm going to break it down into sectors to make it manageable)
2. Thoroughly wash this area with degreaser and sugar soap
3. Wipe surface down with grease and wax remover
4. Sand the area with 120grit sandpaper until uniformly dull (to give the primer a surface to bite into), wash or vacuum o remove dust.
5. Mask off the area *I am NOT removing deck hardware...this is controversial, but I will do this in time and it is unnecessary given the bedding compound tends to ooze out beyond the footprint of the hardware anyhow.
6. Final wipe down with grease and wax remover
7. Apply 2 coats of primer, sand with 220g between and after
8. Wash or vacuum to remove dust.
9. Wipe surface down with grease and wax remover
10. Apply 2-3 coats of top coat.
11. Mask and apply single coat of Kiwi Grip to non skid areas.  Mask radiused areas with 3M stretchy tape.
12. Apply new vinyl "Nonsuch" decals to the cabin sides (the pattern was developed by an enterprising owner some years ago)

Crack filled and sanded