DC ground leakage.

[sailor0500]

I checked my dc using the following system and found I have a "leak" of 3mA on the fridge circuit ( which also has a small spur to the cooker ignition).  To rule out faulty cables which are difficult to access I connected new temporary cables between the switch panel and the fridge. A constant  3mA leak remained therefore I can rule out a cable fault. Switch panel is good so it must be the fridge?

Ideas anyone?

https://www.sailnet.com/threads/how-to-determine-if-my-boat-has-an-electrical-leak.31620/

[dmr]

Leakage is bad and will corrode the hull, that 3mA will eat right through  the baseplate, in 1000 years time you will have nothing left.

 

My money is on the ignition system in the cooker. Can you disconnect the cooker, and then the fridge, as close to each as you can?.

 

..............Dave

[dmr]

and whichever one it is give everything a good clean, fridges can get very damp and mucky at the back near the doings.

 

There is a chance that its due to a component put in to reduce interference etc. don't worry about it.

 

...............Dave

[sailor0500]

9 hours ago, dmr said:

and whichever one it is give everything a good clean, fridges can get very damp and mucky at the back near the doings.

 

There is a chance that its due to a component put in to reduce interference etc. don't worry about it.

 

...............Dave

Thanks for your replies Dave. I did disconnect the ignition system on the cooker but leak still there and fridge is dry, just a bit dusty behind. I know it's an insignificant leak but it's just a puzzle. I did think someone  ( refridgeration engineer? ) would know the answer. Like you I suspected a part in the fridge.

[TheBiscuits]

Just now, sailor0500 said:

Like you I suspected a part in the fridge.

 

It could be the fridge light ... are you completely sure it's going out when you close the door? 

 

[ditchcrawler]

10 minutes ago, sailor0500 said:

Thanks for your replies Dave. I did disconnect the ignition system on the cooker but leak still there and fridge is dry, just a bit dusty behind. I know it's an insignificant leak but it's just a puzzle. I did think someone  ( refridgeration engineer? ) would know the answer. Like you I suspected a part in the fridge.

I dont see how you can have a leakage to earth on a fridge unless the casing is screwed to the steel work

[Tony Brooks]

Just now, ditchcrawler said:

I dont see how you can have a leakage to earth on a fridge unless the casing is screwed to the steel work

Quiet, from what i read on the linked piece I suspect its a unexplained flow from pos to neg rather from pos to earth (the hull). If so I suspect it may be in a 12v fridges control electronics and is normal. Again if so as @dmr said, don't worry about it

[dmr]

18 minutes ago, TheBiscuits said:

 

It could be the fridge light ... are you completely sure it's going out when you close the door? 

 

Or even if there's a dead cat in the fridge ? ?

 

................Dave

[dmr]

10 minutes ago, ditchcrawler said:

I dont see how you can have a leakage to earth on a fridge unless the casing is screwed to the steel work

That's a very good point, that would apply to the cooker too unless its connected with a copper pipe (which still might not be grounded). But any leakage test from positive to negative could pick up all sorts of things, like all the stuff that goes to sleep rather than turning off, so I assume its a leakage to the hull test.

 

..............Dave

[Keeping Up]

Are you sure it's a DC leak, and is it a 12v dc fridge or a 240v ac fridge? A small ac leak to earth is normal from a 240v fridge, due to the rf filters, but highly odd from a dc fridge.

[ditchcrawler]

3 minutes ago, Keeping Up said:

Are you sure it's a DC leak, and is it a 12v dc fridge or a 240v ac fridge? A small ac leak to earth is normal from a 240v fridge, due to the rf filters, but highly odd from a dc fridge.

But that would only flow to earth if you have an earth wire, 12 volt DC is normally just 2 wires so where is the path to earth that the current is being measured in

[Keeping Up]

3 minutes ago, ditchcrawler said:

But that would only flow to earth if you have an earth wire, 12 volt DC is normally just 2 wires so where is the path to earth that the current is being measured in

Precisely, that is why I asked the question (given the title of the thread)

[sailor0500]

13 hours ago, TheBiscuits said:

 

It could be the fridge light ... are you completely sure it's going out when you close the door? 

 

Yes I removed the bulb

[sailor0500]

12 hours ago, Tony Brooks said:

Quiet, from what i read on the linked piece I suspect its a unexplained flow from pos to neg rather from pos to earth (the hull). If so I suspect it may be in a 12v fridges control electronics and is normal. Again if so as @dmr said, don't worry about it

 

12 hours ago, Tony Brooks said:

Quiet, from what i read on the linked piece I suspect its a unexplained flow from pos to neg rather from pos to earth (the hull). If so I suspect it may be in a 12v fridges control electronics and is normal. Again if so as @dmr said, don't worry about it

That was the conclusion I eventually reached when I fitted temporary cables direct from switch board to fridge and the 3mA "leak " remained.

12 hours ago, dmr said:

Or even if there's a dead cat in the fridge ? ?

 

................Dave

I wondered where the cat had gone. Must check that out.

[Tonka]

Do you sleep on a earthing sheet

[sailor0500]

3 hours ago, Tonka said:

Do you sleep on a earthing sheet

Do you?

Edited October 19, 2020 by sailor0500

[Tonka]

12 minutes ago, sailor0500 said:

Do you?

A ground sheet when i go camping

[ditchcrawler]

11 hours ago, Tonka said:

Do you sleep on a earthing sheet

https://scottjeffrey.com/earthing-sheets/