Three DC Electrical System Gremlins

[Blue_Moon]

Forgive the long winded post. I thought it best to get as many observations up front as possible. I have a 2013 Beneteau Oceanis 48 named Blue Moon AKA the “The Moon”.

Gremlin #1. Starting in the summer of 2014, the freezer (Vitrifrigo) has been periodically shutting itself down for no apparent reason. It is probably worth mentioning that the refrigerator which is from the same manufacturer, on the same circuit, using a visually identical compressor has never skipped a beat. Once shut down, the freezer compressor does not restart without intervention. The Beneteau dealer recommended disconnecting and reconnecting the positive wire where it connects to the controller board. That works—temporarily. The same thing can be accomplished by switching refrigeration off and back on from the main panel and/or by turning the entire domestic power supply off and back on. A restart used to keep things running for a day or more. Lately, it is a matter of an hour or two. The controller board has been replaced. That made no difference. The compressor seems hot to me. I shot it with a laser thermometer and it registered 150°F. I don’t know if that is within the normal operating range or not. The keel coolers have been cleaned. That seemed to make no difference.

Gremlin #2. In the spring of 2014, the automatic portion of the master shower sump quit functioning. The manual switch still worked. A repair guy sent to replace the float switch identified a fault in the wiring instead and fixed that instead of replacing the float switch. A few months later, the sump in that shower quit working altogether. We removed the relay that times the pump operation when the manual switch is pressed. When we plugged it back in again, the sump pump began working immediately. We got a new relay. The next time the sump failed, we swapped the old relay for the new one. Shortly afterwards, it failed again. Putting the old relay back in restored proper operation. Since then, we have discovered that doing anything that interrupts power to this circuit and restores it fixes this problem—temporarily.

So we have two completely different systems that quit working for no apparent reason. In both cases, the short term fix is simply to remove and restore power. In fact, they can both be “fixed” at once simply by shutting down the whole domestic power supply and then turning it back on.

Gremlin #3 is not so much a problem as a puzzle. Every time I power up the B&G Zeus Touch Nav system from the main panel, I seem to get a different result. The Moon has four chart plotters (three 7” and one 12”). The Zeus 7 at the nav station can only be turned on and off with the switch on the main panel. When this system was originally installed, that chart plotter was the only thing that came on with the power switch on the panel. The cockpit plotters (7” port and starboard and 12” center) were turned off and on individually or all four could be turned off by turning off the switch on the panel. On a trip in February, the 12” plotter began refusing to turn off except with the switch on the panel. It would appear to turn off but would spring back to life unbidden several seconds after going dark. Then it began coming on automatically when the panel switch was turned on and continued to refuse to turn off with its own power switch. More recently, it has quit coming on automatically but still cannot be turned off except by removing power from the whole Nav system. The two T7’s in the cockpit have continued to function as they always have. They are turned on individually and can be turned off individually or with the panel switch. All four units are on current (v2.0) firmware. The nav station T7 is set to Master. The three cockpit units are set to Slave.

It seems unlikely that these three problems are related in any way apart from all being part of the DC power system. It seems more likely that the freezer and shower sump share a common cause as they both cease functioning for no apparent reason and can both be restored to functionality by simply interrupting and restoring current. I cannot say for certain that the freezer and shower sump fail at the same time but it does seem like, if one has failed, the other has as well.

Theories? Suggestions for further tests? Fixes?

[dlymn]

That sounds like a latching circuit breaker that's reset whenever you reboot the system or take the circuit offline. Also check for the cause of the overload. I had a circuit breaker that cut out every time the bilge pump float turned on. Turned out to be a loose wire to the float switch. On a boat, blame everything on corrosion.

[Blue_Moon]

Originally Posted by dlymn

That sounds like a latching circuit breaker that's reset whenever you reboot the system or take the circuit offline.

That sounds promising but I am not sure what a latching circuit breaker is. Also. it does not appear to me that the shower sump runs through the panel but the freezer does and it's compressor is controlled by the same switch as the compressor for the refrigerator. If a circuit breaker is shutting down the freezer should it not also be shutting down the refrigerator? Any advice on where to find this latching circuit breaker? I thought I knew where all of the breakers were but all of the ones I am aware of, require resetting by hand.

[dlymn]

You might not be looking for a circuit breaker but rather an innocuous tiny box.
Read about latching relays https://en.wikipedia.org/wiki/Relay#Latching_relay

Perhaps these have been installed to protect the system if motors overheated.

I used to have an intermittent fault on my starter motor system which I solved by putting a new wire directly from the starter key to the starter solenoid. The fault, I think, is corrosion in one of the 7 connections between the battery and the solenoid This is one strategy you might try even if it's a temporary one just to see if it makes any difference.

[sailon46]

Originally Posted by dlymn

You might not be looking for a circuit breaker but rather an innocuous tiny box.
Read about latching relays https://en.wikipedia.org/wiki/Relay#Latching_relay

Perhaps these have been installed to protect the system if motors overheated.

I used to have an intermittent fault on my starter motor system which I solved by putting a new wire directly from the starter key to the starter solenoid. The fault, I think, is corrosion in one of the 7 connections between the battery and the solenoid This is one strategy you might try even if it's a temporary one just to see if it makes any difference.

I have the same system in my Beneteau 51.4 Cyclades. I had the same problem with my freezer Italian made Vintifrigo. The problem was in the sea water intake by the compressor (getting hot) and stopping. I had to get a new system in St Martin from the Vintifrigo rep. As far as the other issues you describe I have them too but it seems that panel once shut off and allowed to power back up it fixes things. It has been suggested to me by Beneteau that electric surges are the root cause of it.
Good luck Ernie on The Mary Jane

[Xthewater]

I would suggest looking for a system under-voltage situation which can explain hot temp motor and spurious faults. Shut off and on resets with 12+volts but loading again drags down and problem returns. Corrosion and high resistance connection likely causing the problem.

[mholtzberg]

Since it is a relatively new boat. Can you get the wiring diagrams from Beanatau and chase wires from battery distribution to the physical equipment. Check to make sure that nothing "extra" has been installed. Although, you had the chart plotters installed and maybe someone somewhere they nicked a wire??

[svlamorocha]

Originally Posted by Blue_Moon

Gremlin #1. Starting in the summer of 2014, the freezer (Vitrifrigo) has been periodically shutting itself down for no apparent reason. It is probably worth mentioning that the refrigerator which is from the same manufacturer, on the same circuit, using a visually identical compressor has never skipped a beat. Once shut down, the freezer compressor does not restart without intervention. The Beneteau dealer recommended disconnecting and reconnecting the positive wire where it connects to the controller board. That works—temporarily. The same thing can be accomplished by switching refrigeration off and back on from the main panel and/or by turning the entire domestic power supply off and back on. A restart used to keep things running for a day or more. Lately, it is a matter of an hour or two. The controller board has been replaced. That made no difference. The compressor seems hot to me. I shot it with a laser thermometer and it registered 150°F. I don’t know if that is within the normal operating range or not. The keel coolers have been cleaned. That seemed to make no difference.

The freezer compressor/condensing unit should have a way to tell you why it is shutting down. The typical reason codes are:

(1) Low voltage. To prevent the batteries from being totally discharged, the compressor will be
stopped if the voltage at the terminals on the controller falls below 10.4volts (22.8v on a 24v
system). It will not re-start until the voltage rises above 11.7 volts (24.2 on a 24v system).
(2) High voltage. If the voltage exceeds 17v, the controller stops the compressor and switches into 24v mode, but will not attempt to start the compressor until the voltage reaches 24.2v.
(3) Compressor non-start. If the compressor does not start, the controller will stop the starting process and attempt a re-start approximately every 45-90 seconds.
(4) Compressor speed too low. If the compressor speed falls below 1900 RPM the controller will stop the compressor.
(5) Fan (and pump) protection. If the current draw across the fan terminals exceeds 0.7 amps at 12v dc, the compressor will be stopped and a re-start attempted every 45-90 seconds.
(6) Module overheat. If the heat sink on the controller exceeds 100 deg C (212 deg F), the compressor will be stopped and will be re-started when normal operating temperatures are
resumed

Typically you have or you can install a 12V LED light connected between the + and D terminals of the controller that will tell you (in code) the reason for the shutdown.

Please tell us what specific model of the Vitifrigo line you have. For example, you could have a "Paris 35F air cooled" unit. Please send photos of the labels on the compressor (see to have an idea of what you are looking for).

[svlamorocha]

Originally Posted by Blue_Moon

Gremlin #1. Starting in the summer of 2014, the freezer (Vitrifrigo) has been periodically shutting itself down for no apparent reason. It is probably worth mentioning that the refrigerator which is from the same manufacturer, on the same circuit, using a visually identical compressor has never skipped a beat. Once shut down, the freezer compressor does not restart without intervention. The Beneteau dealer recommended disconnecting and reconnecting the positive wire where it connects to the controller board. That works—temporarily. The same thing can be accomplished by switching refrigeration off and back on from the main panel and/or by turning the entire domestic power supply off and back on. A restart used to keep things running for a day or more. Lately, it is a matter of an hour or two. The controller board has been replaced. That made no difference. The compressor seems hot to me. I shot it with a laser thermometer and it registered 150°F. I don’t know if that is within the normal operating range or not. The keel coolers have been cleaned. That seemed to make no difference.

One easy thing to try is bypassing the thermostat by bridging the C and T terminals with a piece of wire and two female spade terminals. That will make the compressor run nonstop and help you detect a problem with the thermostat.

Another thing to try is to measure voltage across the + and - terminals continuously before, when and after you turn on the breaker.

[Oceanride007]

#1 Suggest that your compressor is to hot, it may have thermister protection (buried in the windings of the motor). So why is compressor getting too hot, probably because its got air in the system. Best way to check is get shroader valves fitted (if they are not already) and monitor your suction and delivery pressure with refrig gauges. If you want to know why this happens, look up law of partial pressures, if you want a cure get a refrigeration mechanic.
#2 sounds like you have a bad connection. Rewire with a junction box that is well away from bilge, this will make fault finding easier and very likely solve the problem.
#3 No opinion.

[tinkrman69]

it could be low voltage on the compressor at startup. if they are on the same circuit the fridge will be on more often than the freezer. you might be overloading the circuit. put the freezer on a different circuit.

trac the shower sump and find what circuit it's tapped into. sine its not an a breaker. it might be overloaded too when it tries to come on whilst the other circuit is on. tap it into a circuit that has less load.

the auto pilot and chart plotters? you've probably overloaded the system with all those terminals, which would burnout an electronic switch. LCD use up a lot of juice.

[JayH]

Gremlin #3 sounds like the yellow (power control) wire might be shorting somewhere. I'd track that wire down and make sure it is not connected to or touching anything. If you don't find a problem, call tech support and get the unit replaced.