GI Leak with inverter

[DJW]

I've recently fitted a galvanic isolator as we spend a fair bit of time plugged into a shore power connection. With the shore power connected the GI lights are off (well, almost off but I'm told by Safeshore, the makers of the GI, that a slight flickering of the LED's is normal with a Sterling charger).

 

What's surprised me is that both GI lights are fully on when the shorepower is disconnected and the inverter switched on - i.e. there is AC leakage. I can't see how this could happen with the shore power disconnected but my understanding of electrics isn't great.

 

Any ideas on how to resolve this? I can take photos of the installation if that helps!

 

Cheers

[eightacre]

The symptoms would suggest that your GI is wired incorrectly. I would expect the GI to be fitted between the boat earth and the shore supply earth, so only active when the shore supply is plugged in.

 

Diagram here: http://www.safeshoremarine.com/diagram%20for%20earth%20wiring.pdf

Edited November 22, 2013 by eightacre

[bottle]

Give Safeshore a ring.

[Keith M]

Is your Inverters output correctly earth bonded or does it have a floating output

 

Keith

[Phil Ambrose]

Is there nothing helpful in the little instruction booklet that comes with the GI?

 

Phil

[by'eck]

I've recently fitted a galvanic isolator as we spend a fair bit of time plugged into a shore power connection. With the shore power connected the GI lights are off (well, almost off but I'm told by Safeshore, the makers of the GI, that a slight flickering of the LED's is normal with a Sterling charger).

 

What's surprised me is that both GI lights are fully on when the shorepower is disconnected and the inverter switched on - i.e. there is AC leakage. I can't see how this could happen with the shore power disconnected but my understanding of electrics isn't great.

 

Any ideas on how to resolve this? I can take photos of the installation if that helps!

 

Cheers

 

Another AC schematic here showing GI connections. As you can see its effectively disconnected when shore power connection is removed which is fine since its only needed when shore power is in use.

 

The GI lights glowing when shore power is disconnected (and inverter on) suggest yours is definitely wired incorrectly.

 

[Phil Ambrose]

Just checked my docs for my Safeshore G.I and 2 LED's lit indicates A.C current leakage.

 

Phil

[DJW]

Thanks all. I agree it sounds like I've wired it into the wrong part of the 240v earth circuit.

 

Back to the drawing board... or the electrics cupboard at least!

[real_vibes]

I have just had a similar issue.

 

For me, I am sure it is correctly wired.

 

We recently list shore power due to flooding and have been using the inverter and running the engine a bit.

 

I had two lights flickering very gently with the engine idling and the inverter on. When I upped the rpm they flicked on a little more strongly as the revs went up and the vice versa when I revved down again.

 

Is this similar to the above post mentioning a little bit of flicker (dull light) being normal or is there an issue?

 

The inverter is a sterling 3kw pure sine wave job. It was only powering the fridge when this occurred.

 

Many thanks

[real_vibes]

(Accidental phone post! Sorry)

Edited January 5, 2014 by real_vibes

[Keeping Up]

I have just had a similar issue.

For me, I am sure it is correctly wired.

We recently list shore power due to flooding and have been using the inverter and running the engine a bit.

I had two lights flickering very gently with the engine idling and the inverter on. When I upped the rpm they flicked on a little more strongly as the revs went up and the vice versa when I revved down again.

Is this similar to the above post mentioning a little bit of flicker (dull light) being normal or is there an issue?

The inverter is a sterling 3kw pure sine wave job. It was only powering the fridge when this occurred.

Many thanks

Are you plugged into the shore line when this happens?

[smileypete]

Probably the inverter isn't earthed internally; if it's supplying more than 2 items and/or the boats fixed AC wiring it should be.

 

One way to tell is get a plug in socket tester which will show up a no earth condition:

 

http://www.amazon.co.uk/gp/product/B00DH2OAZE

http://www.ebay.co.uk/itm/NEW-UK-Mains-Test-Power-Plug-In-Trailing-Socket-Tester-Wiring-Safety-Check-13A-/220859602281

 

IF the earth terminal on the inverter outlet socket isn't connected internally, what needs to be done is this earth terminal should be linked to the neutral terminal on the same socket, to do this does need sufficient electrical competence.

 

It can also be done with a specially wired lead that has the earth and neutral terminals linked inside the plug, and an indelible label indicating it's purpose. But it's better to do it inside the inverter so it's permanent.

 

Once a 'neutral-earth bond' is created it should stop the GI lights flickering, more importantly the RCD/RCBO in the consumer unit will be able to work under fault conditions.

 

Also if the metal case of the inverter is not connected to anything internally, along with the neutral earth bond above, it can help safety wise to connect the casing to the earth terminal on the outlet socket, but again doing this does need sufficient electrical competence.

 

cheers, Pete.

~smpt~

Edited January 5, 2014 by smileypete

[by'eck]

Probably the inverter isn't earthed internally; if it's supplying more than 2 items and/or the boats fixed AC wiring it should be.

 

One way to tell is get a plug in socket tester which will show up a no earth condition:

 

http://www.amazon.co.uk/gp/product/B00DH2OAZE

http://www.ebay.co.uk/itm/NEW-UK-Mains-Test-Power-Plug-In-Trailing-Socket-Tester-Wiring-Safety-Check-13A-/220859602281

 

IF the earth terminal on the inverter outlet socket isn't connected internally, what needs to be done is this earth terminal should be linked to the neutral terminal on the same socket, to do this does need sufficient electrical competence.

 

It can also be done with a specially wired lead that has the earth and neutral terminals linked inside the plug, and an indelible label indicating it's purpose. But it's better to do it inside the inverter so it's permanent.

 

Once a 'neutral-earth bond' is created it should stop the GI lights flickering, more importantly the RCD/RCBO in the consumer unit will be able to work under fault conditions.

 

Also if the metal case of the inverter is not connected to anything internally, along with the neutral earth bond above, it can help safety wise to connect the casing to the earth terminal on the outlet socket, but again doing this does need sufficient electrical competence.

 

cheers, Pete.

~smpt~

But if the GI is wired correctly, one side of it will be connected only to the shore power input earth. If the shore power lead is removed there should be no connection whatsoever to one side of the GI hence no possibility of the GI's diodes conducting, which the LED's suggest is happening.

[smileypete]

I hear what you're saying, hopefully real_vibes will buy a socket tester and try it out while the inverter is running and get back to us.

 

It's a bit hard to be definitive without exact details of how the inverter and fridge is connected and the boat is wired, but if the inverter needs bonding and isn't (and I suspect it isn't) then bonding it is a good first step, yes?

 

cheers, Pete.

~smpt~

[by'eck]

I hear what you're saying, hopefully real_vibes will buy a socket tester and try it out while the inverter is running and get back to us.

 

It's a bit hard to be definitive without exact details of how the inverter and fridge is connected and the boat is wired, but if the inverter needs bonding and isn't (and I suspect it isn't) then bonding it is a good first step, yes?

 

cheers, Pete.

~smpt~

Absolutely

[real_vibes]

ok so I brought the item.

 

whilst the weather is miserable I thought I would just plug it in and see whats what (on shore line) and surprise surprise an interesting result ensues. It reads Live and Neutral in reverse.

 

Can anyone tell me what this means and what it may do to our kit? After 3 years we've had no issues with our shore power.

 

thanks

[smileypete]

The short answer has got to be that it should be investigated and rectified!

Maybe swap the shoreline with another one, then try all the different sockets on the boat. If it still comes up reversed on one or more sockets, then it could be something is miswired between the boats shoreline inlet and sockets. Wouldn't hurt to try the tester straight into the bollard via an adapter too, just in case!

 

Needless to say any changes to the boats mains wiring should to be done or checked by someone with sufficient competence in mains electrics, maybe a local boatyard could help, and charge reasonably too, though any decent spark/electrician should be OK with it.

 

cheers, Pete.

~smpt~

Edited January 14, 2014 by smileypete

[by'eck]

ok so I brought the item.

 

whilst the weather is miserable I thought I would just plug it in and see whats what (on shore line) and surprise surprise an interesting result ensues. It reads Live and Neutral in reverse.

 

Can anyone tell me what this means and what it may do to our kit? After 3 years we've had no issues with our shore power.

 

thanks

 

Neutral is the leg of the AC supply circuit that is strapped to ground earth at some point along the distribution chain before your shore power socket.

 

A polarity checker looks at the two incoming legs of the AC feed, live and neutral, and measures the voltage between each and the earth feed. Normally there should be zero AC volts between neutral and earth (or nearly so) for the reason above, and around 240 volts between live and earth.

 

Reverse of above will give rise to a reverse polarity warning although this may be triggered by an isolation transformer in the shore power feed with the earth left floating with respect to each leg. It should be investigated immediately though by a professional.

 

One problem with full reversal is that single pole breakers and switches fitted in the nominal live feed won't isolate the supply when breaker is tripped or switch is off - worse still there is a possibility however remote, of your boats hull being at 240 volts with respect to an adjacent one.

 

Note also that equipment will appear to work correctly so you will have no other warning.

Edited January 15, 2014 by by'eck

[LadyG]

I seem to have two red lights showing on my Safeshore Marine GI. I have an invertor which is isolated at the moment, [fitted by a proper boat electrician] today I have been cleaning t' engine hole, removing grease and wet stuff, but they may have been red for some while. It has been very wet for weeks, ground is saturated.

Edited February 23, 2020 by LadyG

[Keeping Up]

Is it an inverter or a combi chargeverter?

[LadyG]

Invertor

[WotEver]

Are you on shore power?

[LadyG]

5 minutes ago, WotEver said:

Are you on shore power?

yep

I believe 2 reds = 240v fault

[WotEver]

1 hour ago, LadyG said:

yep

I believe 2 reds = 240v fault

It means that you have an earth leak on the 230V mains. It must be small or the RCD would have tripped.

 

Turn off the main isolator in the consumer unit. Do the LEDs go out?  If not then it’s damp somewhere between the shore power inlet and the consumer unit. If they do go out then it’s an appliance. Turn the isolator back on and disconnect the appliances one by one until you find the culprit. 
 

Good luck

[Keeping Up]

Could it be that the bonding (connection) between the earth of your 240v system and the Hull of the boat has become disconnected? When that happens, even the normal tiny bit of earth leakage from any equipment will illuminate those LEDs.