Shore power trips after a few minutes

[Seren-y-dwr]

Hi hive mind 

 

any idea why? Will obvs discuss with marina tomorrow but just can’t work it out

 

after 2/3 minutes switch on shore charger flips off

 

have tried with my power off and neighbours (shared charge point) on and still happens

 

have tried with engine running/not running

 

have tried with heating running/not running

 

think it’s my boat or the shore line?

[MtB]

Just to clarify, you mean you have a bollard on the bank (or pontoon) and the trip switch on this is what flips off?

 

Does it still do it with every boat unplugged? 

 

If not, plug the boats back in one at a time to figure out which boat is causing it. 

 

Also, can you post a photo of the switch that is tripping please so we can identify what exactly it does? 

 

 

 

[Jen-in-Wellies]

A common cause is water in one of the plugs/sockets. If it has been raining a lot where your boat is, especially if the wind has been driving the rain against one of the connectors, then this is possible. The usual blue connectors are only mildly water resistant (IP44). Disconnect them and you may find water inside, which will allow enough current to bleed across to trip the RCD on the bollard.

 

[StephenA]

30 minutes ago, Jen-in-Wellies said:

A common cause is water in one of the plugs/sockets. If it has been raining a lot where your boat is, especially if the wind has been driving the rain against one of the connectors, then this is possible. The usual blue connectors are only mildly water resistant (IP44). Disconnect them and you may find water inside, which will allow enough current to bleed across to trip the RCD on the bollard.

 

 

That's what we've had with ours - disconnecting and drying them fixes it each time.

[MtB]

34 minutes ago, Jen-in-Wellies said:

A common cause is water in one of the plugs/sockets. If it has been raining a lot where your boat is, especially if the wind has been driving the rain against one of the connectors, then this is possible. The usual blue connectors are only mildly water resistant (IP44). Disconnect them and you may find water inside, which will allow enough current to bleed across to trip the RCD on the bollard.

 

 

Yes agreed. Had a similar problem on Coasty's boat many years ago. Traced it to a joint box in the 240Vac wiring fixed up under the gunwale which was full of water when I took the top off. The water was coming from a window leak trickling down behind the wall panelling then around under the gunwale to the joint box. 

 

 

[Momac]

I agree the shore power cable is the first thing to check . eg try a different cable if possible.

[magnetman]

2/3 minutes it sounds like something on the Boat doing it. 

 

Assuming 2/3 means '2 or 3' rather than "two thirds of a minute" which would be 40 seconds. 

 

Something going on with battery charger, immersion heater or electric kettle. 

 

I've had occasional trips of the bollard safety system (Residual Current Device?) and it seems to be related to dodgy appliances. Having said that I once had a 4 inch spark from a fan heater which didn't trip the breaker. 

 

Dodgy immersion heater going to ground would be my first guess. 

 

Or a kettle. I had a bad electric kettle cause a trip once. 

Oops must read OP properly. 

 

have tried with my power off and neighbours (shared charge point) on and still happens

 

So not the Boat then. 

 

[MtB]

39 minutes ago, magnetman said:

Or a kettle. I had a bad electric kettle cause a trip once. 

Oops must read OP properly. 

 

have tried with my power off and neighbours (shared charge point) on and still happens

 

So not the Boat then. 

 

 

Depends what they mean by "my power off". 

 

If they mean their shoreline unplugged from the bollard then yes, it can't be their boat. But if the shoreline is still plugged in then any sort of current imbalance device in the bollard might still be tripped by their boat, stuff turned ON or not. 

 

Maybe they could come back and clarify. 

 

 

 

 

 

[magnetman]

I was intrigued by the 2/3 minutes thing. 

 

A fault with the inlet would trip it a lot faster than this for a number of different rather obvious reasons. 

 

 

 

I don't know the specs but I think it is milliseconds. 

 

 

It could be a woman thing..

 

Mains on = ? 

 

 

[TheBiscuits]

3 hours ago, Jen-in-Wellies said:

The usual blue connectors are only mildly water resistant (IP44)

 

... And they are usually mounted upside down on boats so they look more waterproof but are actually much less waterproof when connected!

[magnetman]

Yes the spring loaded lid is a bit of a red herring. 

Or maybe a blue herring. 

[Jen-in-Wellies]

7 hours ago, TheBiscuits said:

 

... And they are usually mounted upside down on boats so they look more waterproof but are actually much less waterproof when connected!

The common boat installation has the boat bulkhead mounted connector, with the exposed pins pointed down. This allows water to dribble in to the gap between the plug and socket. Mounting the bulkhead connector with pins up, shields the pins better, with the plug in, as the gap between plug and socket is pointing down, but needs protecting when cruising. The cable entry in to the shore line plug is also exposed this way and some designs will let water in more easily than others.

On my boat, I changed the bulkhead connector from pins down, to pins up and used hot melt glue to help improve the water resistance of the cable entry in to the shore line plug. Not had a problem with this since. My current mooring site also has the shore line connection sheltered from prevailing westerly wind and rain.

Ideally, according to those that use these connectors professionally, the connectors should be on their side to have best waterproofing, but this is rarely an option with the space available on a boat. Especially with an existing system. Others use shields over the bulkhead connector to act as a rain hat. Anything from a properly fabricated metal one, to improvised ones from cut up disposable plastic milk containers.

[GUMPY]

Pins down = wrong

Pins up = wrong

Pins sideways = correct

 

Water will get in in the first two no matter how clever you are.

Water won't usually get in sideways no matter how stupid you are.

 

I used a connector like this

Together with a cap when not in use and an ip67 socket you don't get water in the wiring.

 

 

[Seren-y-dwr]

Thanks everyone for suggestions and questions

 

will try drying

 

yes is bollard at marina - there are two boats plugged in

 

2 or 3 minutes - that’s what is confusing me as I would think a short would happen immediately?

 

will update 

[Jen-in-Wellies]

9 minutes ago, Seren-y-dwr said:

Thanks everyone for suggestions and questions

 

will try drying

 

yes is bollard at marina - there are two boats plugged in

 

2 or 3 minutes - that’s what is confusing me as I would think a short would happen immediately?

 

will update 

It depends what is happening. There is typically two things that can trip in a bollard for each outlet.

• A circuit breaker rated for a particular current, up to 16A, or even 32A in some cases. Prevents overload of the wiring and melting, or fire.
• A residual current device, which will trip if the current flowing in the live and neutral wires differs by more than 30mA. This is a very small current, below that which risks killing someone, if it is flowing through them. There as a safety device.

You've not said which is tripping, so we don't yet know. To tell the apart, the RCD will usually have a test button on it. The breaker will have the trip current written on it. If greater than the circuit breaker current is flowing, then it will trip straight away. I've seen it happen with a poorly run shore lead that has got trapped between the boat and jetty where the cables have been exposed and tripped both the breaker and RCD. Worth checking the lead for damage to the sheath as well. Look for any flattening of the lead, as well as external wear, as the damage may be internal.

If just the RCD is tripping, then a thin film of moisture inside a plug could be just enough allow enough current leakage to trip it. If it is right on the edge, it may take a while to happen.

[rusty69]

The three causes we have had in the past are. 

 

1. Water ingress in the connector from shore to boat. 

 

2.internal damp/condensation in one of the 240v sockets 

 

3.Lazy RCD on shore bollard. Dunno if the springs suffer after time. 

 

3 is the easiest to check by switching to another bollard, then 1,then 2.

Edited December 31, 2023 by rusty69

[magnetman]

If the Boat has its own set of breakers (consumer unit) then its worth setting all of the breakers to OFF and see what happens. If the same happens that would rule out the possibility of it being an on board appliance or socket because everything in the Boat will be OFF.  

 

There might not be a consumer unit. I don't know if all Boats have them. Mine both do. 

Edited December 31, 2023 by magnetman
typo

[Seren-y-dwr]

This is a pic of the bollard 

Have swopped connections between two boats then will try rusty 123

[PeterF]

Some inverters like the larger Victron Multiplus or Quattro have a second AC outlet that is only activated when the shoreline is connected and it turns on after 2 minutes. This is sometimes wired to the immersion heater so that it can not run off the battery, only off the shoreline. Therefore, with the time delay it may be a faulty immersion heater element if wired as above.

[Alan de Enfield]

27 minutes ago, rusty69 said:

.Lazy RCD on shore bollard. Dunno if the springs suffer after time. 

 

We have had this on our caravan park, at about 10 years old the RCD's started to trip. you could reset but they'd just randomly trip again. Replaced with new ones and no further problem.

Now keep a couple in stock JIC.

[rusty69]

Just now, Alan de Enfield said:

 

We have had this on our caravan park, at about 10 years old the RCD's started to trip. you could reset but they'd just randomly trip again. Replaced with new ones and no further problem.

Now keep a couple in stock JIC.

Yes, we've experienced exactly the same thing a number of times. Unfortunately our bollards were submerged a few years ago, and as far as I know the circuit breakers never replaced, so god knows what that did to them. Probably all rusted inside.

[Alan de Enfield]

18 minutes ago, Seren-y-dwr said:

This is a pic of the bollard 

Have swopped connections between two boats then will try rusty 123

 

We have the same system at our marina - on the other side of the bollard will be a bank of 'breaker switches' (one for each of the outlets) and another breaker with a red-button.

 

What is tripping ? 

Is it only your breaker switch, all breaker switches or the 'red-button RCD ?

[Seren-y-dwr]

It’s just the switch shown in the pic that trips (on front of bollard)

 

when I swopped over this tripped on the other outlet which suggests it’s something to do with my boat

 

have only just come back on board after 6 weeks so boat is damp

 

boat is v old (30 years) and mainly 12v with 240 only for plug sockets when on shore power - don’t run kettle or any other electrical devices on board 

Am going to look and see if I can see rcd 

[magnetman]

4 minutes ago, Seren-y-dwr said:

It’s just the switch shown in the pic that trips (on front of bollard)

 

when I swopped over this tripped on the other outlet which suggests it’s something to do with my boat

 

have only just come back on board after 6 weeks so boat is damp

 

boat is v old (30 years) and mainly 12v with 240 only for plug sockets when on shore power - don’t run kettle or any other electrical devices on board 

Am going to look and see if I can see rcd 

 

Is there an immersion heater in the hot water tank / calorifier. I have had a bollard trip from a dodgy immersion heater in the past. 

[nicknorman]

2 minutes ago, Seren-y-dwr said:

It’s just the switch shown in the pic that trips (on front of bollard)

 

when I swopped over this tripped on the other outlet which suggests it’s something to do with my boat

 

have only just come back on board after 6 weeks so boat is damp

 

boat is v old (30 years) and mainly 12v with 240 only for plug sockets when on shore power - don’t run kettle or any other electrical devices on board 

 

The breaker on the bollard can trip for one of two reasons, an overload (too much current) or an earth leakage fault. The latter will trip if the difference in current between live and neutral is more than 30mA. Which doesn't sound a lot, but 30mA flowing through the body is getting close to fatal. Any difference in current between live and neutral arises if there is some sort of conductive path between live or neutral, and earth. The "earth" in question might be the earth wire in the shore cable, the earth wiring inside the boat, the hull (which is hopefully connencted to shore bollard earth).

 

Typicall these sorts of low current conductive paths can be created when there is a damp surface between live and earth, maybe just moisture, maybe a wet insect/spider/ rogue leaf etc. In your case with the "slow blow" it is probably a marginal leakage that is just below the 30mA trip threshold, and then after a short time perhaps there is some warming or other effect that just makes the leakage current breach the 30mA trip point.

 

I haven't fullly read the thread but first step is to use a different shore power cable. If the trip no longer happens, the cable has moisture inside. You can open up the connectors and dry them out (not whilst plugged in, obviously!)

 

If the trip happens with a different cable the problem is inside the boat. Try to unplug or disconnect as many things as you can (not just switching off, actually unplugging) to see if the trip still happens. if if doesn't, you can gradually reconnect things one at a time to see what causes the trip.

 

If it still trips with everything disconnected, check the back of the shore inlet connector for damp/insects etc - again, with the shore power unplugged of course! - and the Consumer Unit / breakers or whatever you have. Undo each 13A socket and check the wiring at the back for damp, insects etc.

In summary, the problem will likely be a small amount of damp or contamination in the wrong place - you just have to find it!