Fridge trouble?

[magpie patrick]

Anyone got any advice on this?

 

Our fridge has a low voltage cut out, but the voltage doesn't seem to have to be very low for it to cut out. Other devices with cut outs work far longer, such as the inverter, as a result we only have a fridge that works if the engine is running or has run recently. This is a pain in the neck at our marina moorings, as I don't really want to run the engine and I haven't yet fitted the hook up stuff (and anyway, the fridge is 12v, so would be run via a battery charger from the land line).

 

Should the low voltage cut out be this fussy? I ran the engine yesterday and it was apparent that the batteries were only slightly down, which is as it should be one week after the last cruise and having been off the boat with all electrics off: i.e. they were 98% charged.

 

Advice from all you sage people would be most appreciated

[Ex- Member]

Anyone got any advice on this?

 

Our fridge has a low voltage cut out, but the voltage doesn't seem to have to be very low for it to cut out. Other devices with cut outs work far longer, such as the inverter, as a result we only have a fridge that works if the engine is running or has run recently. This is a pain in the neck at our marina moorings, as I don't really want to run the engine and I haven't yet fitted the hook up stuff (and anyway, the fridge is 12v, so would be run via a battery charger from the land line).

 

Should the low voltage cut out be this fussy? I ran the engine yesterday and it was apparent that the batteries were only slightly down, which is as it should be one week after the last cruise and having been off the boat with all electrics off: i.e. they were 98% charged.

 

Advice from all you sage people would be most appreciated

 

Could it be the voltage drop. If you fridge is quite a distance from your batteries, you could be suffering a voltage drop, so your batteries may well be near full charge, but the volts reaching your fridge less. Might pay to check the voltage at the batteries, then at the fridge, if voltage at fridge is lower then that could be it. To solve it just fit heavier cable.

[Gibbo]

Might pay to check the voltage at the batteries, then at the fridge, if voltage at fridge is lower then that could be it. To solve it just fit heavier cable.

 

Almost certainly BUT..... take the measurements when the fridge is actually running (the compressor motor going) otherwise there won't be any voltage drop.

 

Gibbo

[Tony Brooks]

Almost certainly BUT..... take the measurements when the fridge is actually running (the compressor motor going) otherwise there won't be any voltage drop.

 

Gibbo

 

Again BUT - the problem seems to be the starting surge which is admitted as (from memory) over 30 amps but I suspect may, for an instant, be a lot higher.

 

Unless you have a very fast storage scope and know how to operate it I suspect you would not be able to measure the voltdrop at starting.

 

If the low voltage goes of at random times whilst the fridge is running then doing what Gibbo advises should sort the problem out but if it consistently operates on startup I think you need to:

 

1. Double check the battery state of charge and condition.

 

2. Clean, Vaseline and refit the battery terminals.

 

3. Work through the wiring looking for loose/dirty connections

 

4 - and this one is probably the whole cause. Check the cable size against the recommendations which are 1 sq mm of conductor cross sectional area for each meter of run between the battery and fridge. Use the same for the return.

 

I have seen a Liverpool Boats fitout wire, from new, with totally inadequate cable and also have an example of someone who advertises their expertise in wiring looms also ignoring the manufacturer's guidance.

 

The Danfoss website explains how to alter the jumpers at the back of the fridge to lower its cutout voltage, but I would prefer to get the cables right.

Edited July 6, 2008 by Tony Brooks

[Triss48]

Anyone got any advice on this?

 

Our fridge has a low voltage cut out, but the voltage doesn't seem to have to be very low for it to cut out. Other devices with cut outs work far longer, such as the inverter, as a result we only have a fridge that works if the engine is running or has run recently. This is a pain in the neck at our marina moorings, as I don't really want to run the engine and I haven't yet fitted the hook up stuff (and anyway, the fridge is 12v, so would be run via a battery charger from the land line).

 

Should the low voltage cut out be this fussy? I ran the engine yesterday and it was apparent that the batteries were only slightly down, which is as it should be one week after the last cruise and having been off the boat with all electrics off: i.e. they were 98% charged.

 

Advice from all you sage people would be most appreciated

 

Is it a Shoreline? If so the nice people at Shoreline will send you a self fit bit of kit that renders the fridge less sensitive. I had the smae probelm and that fixed it.

[Justme]

4 - and this one is probably the whole cause. Check the cable size against the recommendations which are 1 sq mm of conductor cross sectional area for each meter of run between the battery and fridge. Use the same for the return.

 

 

My understanding was that the TOTAL feed & return length should be use to work out the 1 sq mm CSS per metre not for each sepperatly.

 

 

Justme

[Tony Brooks]

My understanding was that the TOTAL feed & return length should be use to work out the 1 sq mm CSS per metre not for each sepperatly.

 

 

Justme

 

 

I quote what Shoreline recommended on my fridge and also worked out what the Danfoss website says. I think Shoreline chose that way of expressing it to save bothering customers with 0.5 sq mm per each meter of total run.

 

Anyway using 1 sq mm for each meter of total run will not do any harm apart from attaching suitable terminals and paying for it. electrically its fine.

[magpie patrick]

Thanks guys, I knew you'd have answers. All makes sense as the batteries were still well charged and the inverter still going after 48 hours without running the engine, but the fridge refused to cooperate.

 

The shorter term solution is purchase of a cool box (second hand, £1) for use on non-moving weekends, the longer term is a heftier cable, the fridge is about 40 feet from the batteries.

 

I'll test for voltage drop, noted re: fridge running but as it works through one of those diddy three pin plugs I have ways of simulating the load.

 

One problem with an ex-hire boat, they seem to have got away with several fudges on the basis that the boat would always move every day, 30 hours or more a week. The engine doesn't like non-activity either.

 

edited coz I didn't want anyone suggesting that FUNNING your fridge was immoral and possibly illegal

Edited July 7, 2008 by magpie patrick

[ditch paddler]

Anyone got any advice on this?

 

Our fridge has a low voltage cut out, but the voltage doesn't seem to have to be very low for it to cut out. Other devices with cut outs work far longer, such as the inverter, as a result we only have a fridge that works if the engine is running or has run recently. This is a pain in the neck at our marina moorings, as I don't really want to run the engine and I haven't yet fitted the hook up stuff (and anyway, the fridge is 12v, so would be run via a battery charger from the land line).

 

Should the low voltage cut out be this fussy? I ran the engine yesterday and it was apparent that the batteries were only slightly down, which is as it should be one week after the last cruise and having been off the boat with all electrics off: i.e. they were 98% charged.

 

Advice from all you sage people would be most appreciated

I replaced my fridge last year with a shoreline and had a very similar problem, shoreline where very helpful and sent an enginner out twice and ending up changing the control they told me they had recieved a faulty batch of control units, problem now solved.