LEC 12v fridge misbehaving mysteriously

[Odana]

We have a LEC under counter 12v fridge with freezer box. All electric is run through a Victron and 4traction batteries - we are plugged into shoreline. Intermittently since we bought the boat and pretty much all the time now the red light pulses (single flash every five seconds) and its not working well at all. This would normally we guess mean low battery voltage, but it happens even when we are plugged in and the Victron is on float or on charge. Also when the engine is on. We're going to disconnect batteries and test them all individually this weekend, but everything else is fine so we suspect it might be something else causing the problem.

 

Does anyone have any ideas what the 'something else' might be? What else do we need to be checking while we are at it?

 

many thanks!!

[nb Innisfree]

Our Lec has occasionally behaved the same since new in 2004, code indicates compressor overpressure, we just turn it off for a while.

[Delta9]

We have a LEC under counter 12v fridge with freezer box. All electric is run through a Victron and 4traction batteries - we are plugged into shoreline. Intermittently since we bought the boat and pretty much all the time now the red light pulses (single flash every five seconds) and its not working well at all. This would normally we guess mean low battery voltage, but it happens even when we are plugged in and the Victron is on float or on charge. Also when the engine is on. We're going to disconnect batteries and test them all individually this weekend, but everything else is fine so we suspect it might be something else causing the problem.

 

Does anyone have any ideas what the 'something else' might be? What else do we need to be checking while we are at it?

 

many thanks!!

Is the cable running to the fridge thick enough? you could be getting a voltage drop if it is too thin.

 

Our Lec has occasionally behaved the same since new in 2004, code indicates compressor overpressure, we just turn it off for a while.

I believe it's three flashes for the compressor fault. Mine was doing the same but it mostly stopped after I defrosted it.

[Phil Ambrose]

My LEC 12v fridge is fed by 25mm sq cable. 30 feet from battery bank.

 

Phil

[Odana]

Will check cable. But for 9 months it has mostly been fine so I'm suspecting cable thickness ok.

 

Have found manual which says one flash is voltage to fridge connections. But comments above about compressor made me think. The freezer compartment door broke last month and doesn't seal well at all. Could this have any effect such as overloading the compressor and ..... not sure here.

 

Thanks for advice

Edited August 16, 2013 by Odana

[nb Innisfree]

What voltage,are you using, 12 or 24?

[Odana]

12v

[George94]

What voltage,are you using, 12 or 24?

 

You'll generally find that a "LEC 12v fridge" runs on 12V.

 

In my experience anyway.

[trackman]

We have a Shoreline similar to yours. Once in a while it does exactly this, and doesn't run.

Flicking off the breaker on the relevant circuit resets it and it's fine again for months.

The cable to the fridge is plenty big enough and it has never been associated with low battery charge. It appears to be a quirk of the fridge, perhaps triggered by a voltage spike or such. We've never been able to discover what though.

Ours is coming up to 7 years old now, so we are not panicking!

[nb Innisfree]

I was asking because our Lec is identical to a Shoreline, i.e. 12/24v, automatically switches to the voltage presented. We had problems with low voltage on our 24v batt bank causing the fridge to cut-out, when we investigated it transpired that the cutout voltage on 24v setting is a bit low and cut-in a bit high. I contacted Lec and asked if something could be done but they said no as it is built in to the pcb. To find out if Shoreline had the same prob I contacted them and was told it was a common prob and I could overcome it by removing a resistor and bridging between connections 'C' & 'P' they even offered to post me a made up cable. When I mentioned Lec's advice they said Lec don't know their own product and Shoreline had been doing that mod for years!

 

I declined their offer of a cable and made my own, it worked perfectly.

 

ETA: Our AGM batteries recovered after several long absorption charges, that was 4years ago and they are performing fine with normal voltages.

Edited August 16, 2013 by nb Innisfree

[bizzard]

Never get spikes and nonsense with my old gas fridge, the flame never goes out.

[nb Innisfree]

We have a Shoreline similar to yours. Once in a while it does exactly this, and doesn't run.

Flicking off the breaker on the relevant circuit resets it and it's fine again for months.

The cable to the fridge is plenty big enough and it has never been associated with low battery charge. It appears to be a quirk of the fridge, perhaps triggered by a voltage spike or such. We've never been able to discover what though.

Ours is coming up to 7 years old now, so we are not panicking!

Exactly like ours, we get just the single flash even though voltage is ok, a quick reset sometimes does it but often it needs switching off for an hour or two. As you say a bit quirky but not a big problem, ours is 9 years old now.

[George94]

I was asking because our Lec is identical to a Shoreline, i.e. 12/24v, automatically switches to the voltage presented.

 

I declined their offer of a cable and made my own, it worked perfectly.

 

Whoops. That's what you get for being a smart-arse.

[nb Innisfree]

 

Whoops. That's what you get for being a smart-arse.

??

[George94]

??

 

The smart-arse being me!

[nb Innisfree]

 

The smart-arse being me!

Oh right! That's how my missus read it, I can be a bit thick at times.

 

You're not trying to take my smart-arse crown are you?

[MtB]

We have a LEC under counter 12v fridge with freezer box. All electric is run through a Victron and 4traction batteries - we are plugged into shoreline. Intermittently since we bought the boat and pretty much all the time now the red light pulses (single flash every five seconds) and its not working well at all. This would normally we guess mean low battery voltage, but it happens even when we are plugged in and the Victron is on float or on charge. Also when the engine is on. We're going to disconnect batteries and test them all individually this weekend, but everything else is fine so we suspect it might be something else causing the problem.

 

Does anyone have any ideas what the 'something else' might be? What else do we need to be checking while we are at it?

 

many thanks!!

A single flash every five seconds is low input terminal voltage. So the next step is to remove the fridge and measure the input terminal voltage with the engine running, Victron ON or whatever it takes to make the red light flash.

 

If the terminal voltage is up at 13.5v + (which I would expect with the engine running, etc) then your fridge electronics are fooked (technical term). If the terminal voltage is 12v or less then then it is something creepy going on with the boat electrics, not the fridge.

 

Do check and report back!

 

MtB

 

 

(Edit to change a word so the sentence makes sense)

Edited August 17, 2013 by Mike the Boilerman

[nb Innisfree]

I was asking because our Lec is identical to a Shoreline, i.e. 12/24v, automatically switches to the voltage presented. We had problems with low voltage on our 24v batt bank causing the fridge to cut-out, when we investigated it transpired that the cut-out voltage on 24v setting is a bit low and cut-in a bit high. I contacted Lec and asked if something could be done but they said no as it is built in to the pcb. To find out if Shoreline had the same prob I contacted them and was told it was a common prob and I could overcome it by removing a resistor and bridging between connections 'C' & 'P' they even offered to post me a made up cable. When I mentioned Lec's advice they said Lec don't know their own product and Shoreline had been doing that mod for years!

 

I declined their offer of a cable and made my own, it worked perfectly.

 

ETA: Our AGM batteries recovered after several long absorption charges, that was 4years ago and they are performing fine with normal voltages.

Just to clarify, the red text should read both voltage cut-out and cut-in are a bit high.

 

Factory settings below.

 

Cut-out Cut-in

 

12v : 10.4v 11.7v

 

24v : 22.8v 24.2v

 

As can be seen 24v settings are too high, maybe it has been corrected on later models?

Edited August 17, 2013 by nb Innisfree

[smileypete]

A google search for 'Danfoss BD50 PDF' should turn up a manual with details of how to modify the cut out and cut in voltages.

 

cheers, Pete.

~smpt~

[Peter Reed]

Never get spikes and nonsense with my old gas fridge, the flame never goes out.

I bet You're still driving a 1958 A40 Farina.

[Tony Brooks]

 

A single flash every five seconds is low input terminal voltage. So the next step is to remove the fridge and measure the input terminal voltage with the engine running, Victron ON or whatever it takes to make the red light flash.

 

If the terminal voltage is up at 13.5v + (which I would expect with the engine running, etc) then your fridge electronics are fooked (technical term). If the terminal voltage is 12v or less then then it is something creepy going on with the boat electrics, not the fridge.

 

Do check and report back!

 

MtB

 

 

(Edit to change a word so the sentence makes sense)

 

Afraid not MtB.

 

No one will give me figures but I am fairly sure that what Danfoss quote as the maximum current draw is far less than it actually is. (and I do not mean the few amps they quote as an average)

 

From what I can see these compressor units have an exceptionally and unusually high starting surge current but it is only present for a few microseconds. This means any voltdrop it causes can be acted upon by the electronic control unit but will be over before either a digital or analogue meter can respond. This is why the fridges need such huge cables for their 4 ampish draw.

 

If the OP has access to a very fast storage scope they may be able to measure the voltdrop but as they do not then I suspect they will have to content themselves with checking all connections, fuses and switches in their circuit for causes of excess voltdrop.

 

It could even be that their batteries are now failing so drop to a lower voltage than they did before.

 

There is no way an ordinary boater or even most electricians can take a meaningful voltage reading to diagnose this sort of problem.

[lockedout]

Spooky....

 

We got back yesterday from 3 lovely weeks on the boat and the only problem we had (well apart from having to re-plumb the bathroom sink) was with our LEC fridge.

 

On 'moving days' the fridge was no problem at all. On 'sitting still' days the fridge would frequently exhibit the single flash error code sometime in the late afternoon or early evening. The SmartGuage showed the battery bank at 100% and a steady 12.7 to 12.8 volts.

 

The 'cure' was to turn the engine on for half an hour and the fridge reset itself. Annoying, but not mission critical. I have the Book of Words for the fridge and I thought that the problem was most likely caused by the voltage range being set wrongly. I wasn't going to fiddle with it while we were out, but I will have the fridge out in the next couple of weeks and have a play with what appear to be the four possible voltage settings, but I need to do some more research before I get started.

 

I will also check the cable sizing when I get the fridge out - it is a 9 year old Liverpool Boat, I would hope the cable would be big enough, but who knows.

 

all the above info is most useful, please keep it coming. I really don't want to have to replace the fridge!

[Tony Brooks]

In that case I definitely suspect wire size, had it before on a Liverpool Boats fit-out.

 

Remember 1sq mm of conductor cross sectional area for each metre between battery and fridge with the same for the negative. In many cases you are talking close to starter cable size (but more & thinner strands).

 

Make sure any fuses are clean and making good tight contact.

[MtB]

 

 

 

Afraid not MtB.

 

No one will give me figures but I am fairly sure that what Danfoss quote as the maximum current draw is far less than it actually is. (and I do not mean the few amps they quote as an average)

 

From what I can see these compressor units have an exceptionally and unusually high starting surge current but it is only present for a few microseconds. This means any voltdrop it causes can be acted upon by the electronic control unit but will be over before either a digital or analogue meter can respond. This is why the fridges need such huge cables for their 4 ampish draw.

 

 

Agreed. This seems the most likely hypothesis to me now you've suggested it.

 

A pragmatic approach to diagnosis might be to lug a freshly charged battery into the kitchen and connect it to the fridge using a nice fat, short pair of cables and see if the fridge runs properly.

 

If it does, this indicates a power supply problem with the boat wiring, probably a high resistance joint somewhere. This assumes the problem is a new one and the fridge used to work correctly, although on reading the OP it appears we don't know the history of the problem.

 

MtB

[lockedout]

In that case I definitely suspect wire size, had it before on a Liverpool Boats fit-out.

 

Remember 1sq mm of conductor cross sectional area for each metre between battery and fridge with the same for the negative. In many cases you are talking close to starter cable size (but more & thinner strands).

 

Make sure any fuses are clean and making good tight contact.

 

Thanks Tony,

 

I will have a look when I get the fridge out over the BH weekend. I must say, I am not looking forward to having to replace the cable if it turns out to be too light, but I guess if it needs doing, I will just have to get on with it!

 

I did check the fuses when I first noticed the fault occuring, or at least, the ones I could find, and everything seemed ok but a squirt of WD and a quick clean never hurts.

 

Boats and Electricity eh?????