Shore power

[Kezza]

Not sure I'm writing this in the right section but I have a question.

Why does my shore power work for weeks at a time the trip?

As soon as I flip the switch outside everything works.

[nicknorman]

9 minutes ago, Kezza said:

Not sure I'm writing this in the right section but I have a question.

Why does my shore power work for weeks at a time the trip?

As soon as I flip the switch outside everything works.

Tricky to fault find something that works ok for weeks…

 

Likely it is the RCD aspect that is tripping, due to a slight earth leak somewhere. Slight differences in humidity, a spider crawling by etc might just push the leakage current over the 30mA threshold. Water ingress into the cable plugs? Or maybe the bollard RCD has become too sensitive.

 

Can you try a different bollard socket?

Closely inspect the shore cable including inside the plug and socket, for any damage, damp or debris that could be allowing leakage current. Unplug any appliances when not actually in use to see if that helps.

Edited September 23, 2022 by nicknorman

[Bod]

You are using to much electricity.

Either by way of having too many items on at the same time, or an item which has a fault.

Shore lines are generally much lower "power" than house supplies, imagine trying to run a house on one 13 amp plug, which is the "power" generally supplied by shore lines.

When you shore line trips, are you using a particular item?

 

Bod

[Jen-in-Wellies]

Is it the MCB, or RCD that is tripping out? The RCD will likely have a test button on it. If it is the RCD, then see @nicknorman's reply. If the MCB, see @Bod's reply.

[rusty69]

Also, is it your individual circuit breaker that is tripping or a shared one.

 

Otherwise Nicks comment covers it. They do become lazy after a while and trip for no apparent reason. 

[Kezza]

Thanks for the advice. I can't plug into another socket unfortunately. It just seems really odd and it puzzles me. When it happens it only happens in the morning. The boat attached to same pedestal doesn't have any issues 

[nicknorman]

1 minute ago, Jen-in-Wellies said:

Is it the MCB, or RCD that is tripping out? The RCD will likely have a test button on it. If it is the RCD, then see @nicknorman's reply. If the MCB, see @Bod's reply.

Trouble is it’s likely to be a combined MCB and RCD on a shore bollard. He says “As soon as I flip the switch outside everything works.” so I take from that that it’s the shore bollard breaker.

[Kezza]

I'm not using anything different on the boat. And if it was a faulty appliance wouldn't the electrics flip on the boat?

[Jen-in-Wellies]

1 minute ago, nicknorman said:

Trouble is it’s likely to be a combined MCB and RCD on a shore bollard. He says “As soon as I flip the switch outside everything works.” so I take from that that it’s the shore bollard breaker.

On my shore bollard, they are separate. Not seen a combined MCB/RCD used, but I don't doubt some bollards use them.

[Kezza]

Yes it's the shore bollard

[Jen-in-Wellies]

3 minutes ago, Kezza said:

I'm not using anything different on the boat. And if it was a faulty appliance wouldn't the electrics flip on the boat?

Slight differences between the breakers actual trip currents could cause this. Even two 16A breakers will trip at slightly different currents. Also, the bollard might have a lower rating breaker, 6A, or 10A, if the wiring is limited in the shore supply to them, so that will trip first.

This is assuming it is an over current situation that is tripping the bollard, not an earth leakage.

Again, does the breaker that is tripping have a test button on it, or not?

Edited September 23, 2022 by Jen-in-Wellies

[Kezza]

Thanks for all the advice I'll get someone in to check it out

[Jen-in-Wellies]

4 minutes ago, Kezza said:

I'm not using anything different on the boat. And if it was a faulty appliance wouldn't the electrics flip on the boat?

An earth leakage might not cause the boat RCD to flip out if it has been wired incorrectly. This is more common on boats than is good for ones peace of mind.

[Momac]

Try a different shore power cable.

[Kezza]

No it doesn't have a test button and I'm not using anything different. It does not happen when I switch on a particular device.

[jonathanA]

OK if the breaker you are resetting does not have a test button then we must assume it is an MCB (overcurrent device).  See bods post.

 

Look for the rating of rhe breaker it will be on it. Typically 16A but could 10 or 6 or something else.  Given the intermittent nature it could be that you're getting close to the limit of the breaker buts it's taking a while to actually trip. Or maybe you have a couple of things that switch on and off by rheselves fridge, immersion heaters that sort of thing and if one or more happen to switch on at the same time they may be the cause of the trip. 

Edited September 23, 2022 by jonathanA

[MtB]

When there was a similar problem on Coasty's bote, I eventually found the problem was a joint box screwed to the underside of the gunwale below a window, and filled with water.

 

Fixed the window leak, dried out the joint box and the tripping went away.

 

 

[Jen-in-Wellies]

9 minutes ago, jonathanA said:

OK if the breaker you are resetting does not have a test button then we must assume it is an MCB (overcurrent device).  See bods post.

 

Look for the rating of rhe breaker it will be on it. Typically 16A but could 10 or 6 or something else.  Given the intermittent nature it could be that you're getting close to the limit of the breaker buts it's taking a while to actually trip. Or maybe you have a couple of things that switch on and off by rheselves fridge, immersion heaters that sort of thing and if one or more happen to switch on at the same time they may be the cause of the trip. 

@Kezza, if you can't work out what the rating is, post a photo of the breaker.