AC tripping fuse

[Paul_S123]

Air Con keeps tripping breakers on the P50.

Non of this happens when you actually turn the ac on at the individual panels, this is just having the main power turned on, and all the units and control panels switched off.

On shore power, (my shore power has 2 leads and 2 separate circuits..one for domestic and one for ac), if you go in the crew cabin..there's 2 breakers, one for dom one for ac. The ac one trips...try to reset it and it trips the one ashore.

On generator, the ac power light come up on the dash, but it will now trip the main ac breaker in the main panel down in a guest cabins.

Like I said, this is happening without actually trying to turn the ac on at any of the control panels.

 

[Chris H]

Air Con keeps tripping breakers on the P50.

Non of this happens when you actually turn the ac on at the individual panels, this is just having the main power turned on, and all the units and control panels switched off.

On shore power, (my shore power has 2 leads and 2 separate circuits..one for domestic and one for ac), if you go in the crew cabin..there's 2 breakers, one for dom one for ac. The ac one trips...try to reset it and it trips the one ashore.

On generator, the ac power light come up on the dash, but it will now trip the main ac breaker in the main panel down in a guest cabins.

Like I said, this is happening without actually trying to turn the ac on at any of the control panels.

Is the a/c trying to start ?

I would find the local isolation at the a/c unit and switch it off, if it still trips, it’s the wiring.....process of elimination before getting a sparky involved.

 

[Paul_S123]

Is the a/c trying to start ?

I would find the local isolation at the a/c unit and switch it off, if it still trips, it’s the wiring.....process of elimination before getting a sparky involved.

No not trying to start, just tripping without trying to turn on any of the units

 

[jrudge]

Are they individual units or a central compressor ?

 

[Paul_S123]

Individual units.

 

[Portofino]

Tried generator with the AC shore lead disconnected at the boat ?

 

[jrudge]

So the wiring should be simple

Shore / breaker / switch / individual units

There will be commonality with the water pump which will more likely than not serve them all. This also has a control box.

I would disconnect one by one starting at the pump ( lots of water ). Eventually it will stop tripping and you will have found the fault.

Depending on how it is wired you would either do this at each unit / pump or if you are lucky there is some sort of bus that distributes power from the ac switch where you can disconnect one at a time. Do you not have individual isolators for each unit at your switch panel?

Finally at the risk of the obvious have you swapped the shore cables over to make sure the fault does not lie there ?

 

[Paul_S123]

Yes have tried with shorepower unplugged and running on genny.

When on genny, power led lights up on dash switches, but the breaker is tripped immediately at the main ac breaker at the main distribution panel.

On shorepower, no led on dash as the breaker on the shorepower ac main is tripped instead. Flick that to on and it trips the one in the marina power outlet.

I guess it's tripping the weakest breakers up the line.

 

[Paul_S123]

So the wiring should be simple

Shore / breaker / switch / individual units

There will be commonality with the water pump which will more likely than not serve them all. This also has a control box.

I would disconnect one by one starting at the pump ( lots of water ). Eventually it will stop tripping and you will have found the fault.

Depending on how it is wired you would either do this at each unit / pump or if you are lucky there is some sort of bus that distributes power from the ac switch where you can disconnect one at a time. Do you not have individual isolators for each unit at your switch panel?

Finally at the risk of the obvious have you swapped the shore cables over to make sure the fault does not lie there ?

Have a seperate breaker for the pump, tried with this switched on or off.

Do have rocker switches on the dash for the individual units...tried turning them all off and it still trips.

 

[jrudge]

So I would physically disconnect from the main ac breaker on the panel and go from there.

Each unit will probably have some form of junction and physically disconnecting live and neutral and you will eventually find the issue.

 

[Seastoke]

Yes it sounds like you have neutral to earth fault ,and some breakers only turn off the live side so ,yes you need to disconnect the live and neutral ps turn the power off first,also when you say tripping is it the breaker or the rcd

 

[jrudge]

Yes it sounds like you have neutral to earth fault ,and some breakers only turn off the live side so ,yes you need to disconnect the live and neutral ps turn the power off first,also when you say tripping is it the breaker or the rcd

I thought that .... but I also recalled that neutral and earth on a boat were bonded ? So in a house yes, on a boat .... I assumed not ( could easily be wrong)

 

[Seastoke]

No not bonded because if the boat say the neutral came out of the plug the earth wire would become the neutral making every metal that is farther become live. Marinas are also not bonded together also petrol stations .

 

[jrudge]

Generators are bonded neutral / earth ( never understood fully ) so assumed whole boat was

 

[Seastoke]

I could be wrong

 

[Paul_S123]

Just to add to equation, I have been thinking back...last month I took the boat to Morocco, my shorepower lead fits directly into the sockets here at Sotogrande..although my neighbours all use an adaptor. When we went into the marina there, my friends lead worked and mine now needed an adaptor (which I had). It was plugged in and everything worked fine (including ac).

Unplugged, came back to Spain..plugged into the marina...the power was tripped, assumed it was in their box...called marinero who came and reset it. We went home a day or two after that after not using the ac at all.

So it was working fine, came back, plugged and and has probably not worked since then.

 

[Hurricane]

Is it a circuit breaker tripping or an RCD.
If RCD, it could be a problem with the earth.

If you are saying that there have been problems with your shore power cable, it would make sense to start at the beginning.
When plugging into a new shore supply, I always check the following:-
1 - that shore supply live is 240/220v above the shore supply ground.
2 - that shore supply neutral to shore supply ground is as near ans makes no difference to 0v
3 - that shore supply live to shore supply neutral is 240/220v
And all this BEFORE plugging in.
On both supplies - independently.

Then take your shore supply leads apart and check them for corrosion.
Only then start debugging your boat.

Fault finding is all about starting with something that works and gradually work into the problem.

 

[Paul_S123]

Trips both. If on generator with shorepower lead unplugged..it instantly trips the a/c rcd on the main distribution panel. If you plug in the shorepower lead..it trips the ac side of the shorepower input breakers in the crew cabin or the breaker on the onshore hook up box on the jetty. So I don't think it's the shorepower lead as the rcd trips with it disconnected and running on generator

 

[Hurricane]

Trips both. If on generator with shorepower lead unplugged..it instantly trips the a/c rcd on the main distribution panel. If you plug in the shorepower lead..it trips the ac side of the shorepower input breakers in the crew cabin or the breaker on the onshore hook up box on the jetty. So I don't think it's the shorepower lead as the rcd trips with it disconnected and running on generator

OK but I would still check the shore power leads first even though this doesn't look like the problem.
On our Princess, each of the 5 A/C systems is controlled from a separate switch on the main panel.
Do you have a similar system where you can isolate each A/C system and gradually bring them on until it fails.
If any of the A/C systems causes it to trip. remember that the raw water cooling pump will switch on.
There might be a failure of the raw water pump - going to ground or simply overloading.
If you don't have a means of isolating the individual A/C units, try disconnecting the pump.
Then continue disconnecting stuff until the system doesn't trip.

 

[Paul_S123]

I do have individual switches on the dash electrical panel, they are momentary rocker switches, I have tried it with them all switched off, plus the breaker for the pump switched off and the rcd still trips (on gen)