NigelD

I would like to contact Wol at Debdale, is he a member of the forum or does anyone have his contact details. Regards Nigel

Thanks, who knows - may even buy a washing machine to go with it

Has been now and all cleared up - so thanks for all the great help!

Super - thanks, I now "seem" to have the bigger picture - great! On this link: http://www.airlinktransformers.com/boating_transformers/ ​There are two ITs (i am not saying I'll buy one), "1600va 230v to 230v Isolating transformer for Boats to prevent Galvanic corrosion" 150.00 pounds and 3600va 230v to 230v Isolating transformer for Boats to prevent Galvanic corrosion 240 pounds So not such a bad price considering my GI cost me 120 pounds (probably paid to much)! ​Strange that they focus on Galvanic corrosion - although this is a very hot topic.

So much has been said that I must confess, I am loosing track of where I started from. Regardless of this, the discussion thus far has helped me immensely so thanks for that. I do like the sound of the IT (even if a little more expensive) as would possibly help get rid of many issues around a shore line and its nasty galvanic side effects as well as enabling me to potentially connect any genny without having to worry about how it looks electrically. Am, right in saying a) I would not need a galvanic isolator and regardless of the generator/supply attached I would have E-N 0V and L 230V, which would eliminate E-N possibly being at 110V.? Also, I "suspect" the IT is better at dealing with the shore line earth drifting about than a GI. If I understood correctly, the GI only protects up to a couple of volts and above this "passes through" in which case, the earth is no longer galvanically isolated. I assume that an IT won't do this? Sorry to bring this up but we may as well have it all on the table.

If you connect a portable genny into the IT can you then earth neutral bond the IT output regardless of the type of genny being used - centre tapped or floating and have E-N 0V, L 230V?

The reason I mentioned the "local earth" is that I read on here that on some portable generators the earth pin has nothing to do with the output earth and is only there incase there is a wiring fault internally and the chassis of the generator goes live (relative to what, I am not sure) Now, this is a fault condition not a permanent condition. So the genny is sitting on rubber feet and the chassis is live. For this reason, I was considering a simple local earth bolted to the hull near the genny and connected to the genny earth pin. This would hopefully provide a quick kill. Note: no current over this connection before or after the fault just during the fault. The other "regular use condition" would need an earth return path incase of a leak etc via the bonding point (if needed). I have not persuaded this discussion further as I am not sure that I need it before I check my genny out. I hope I have not caused more confusion? PS batteries and consumer unit/bonding point in the "trad" engine room.

OK. Thanks for all the replies - a great help

Please bear with me here. The genny has an earth pin which earths the chassis in the event of an internal fault and the chassis goes live (wire rubbing etc)? Should this then be ignored? The shore line earth is bonded via the consumer unit to earth and via the bollard? If the genny is centre tapped then OK the earth is at the mid point and wired back with the N and L. If the output is floating and not earthed, then if a wire is exposed, then a potential is present but nowhere to go for the moment (don't really feel comfortable with this but ok). as an aside, I thought the human body also acts as quite a large capacitor so there would be a shock and flow of current all be it not much - perhaps this is wrong though. Concerning the second consumer unit I think this is what I will do, seems to be the solution - thanks for the reply.

OK, great. yes, safety is the main concern as I know it is very easy to inadvertently damage the insulation of a cable without leaving a short circuit, there could be bare copper wiring waiting for someone (probably me) to touch. Admittedly, it not likely but still a risk and with so much steel and water around I would like to close this off. With regard to the Victron multi although a very sophisticated piece of kit, it has left me with one or two issues: 1. Immersion heater and fridge: The fridge is 12v but has a black box which enables the fridge to be powered by 12v dc or 220V ac, works automatically. Now, when on a shore line, then its nice to have these running off it BUT I have to switch the multi on to charge mode to pass the mains through! It seems to isolate everything when off, which I can understand, again from a safety aspect. 2. With the above in mind, When the solar is working (most of the day), I don't really want the charger battling it out with the solar system about who will charge the batteries, just so that I can have power passed through. 3. I do like to have the multi off when possible as it does buzz a fair bit and at night with no solar, then the batteries have to keep the fridge supplied - about 50W I think. Not a big problem but definitely not optimal. I had thought of putting in another consumer unit in with RCD (T'ed in before the Viltron) just for the immersion heater and fridge but seems a of an over kill? Any ideas?

Thanks for this, its a great help, it's how I have done it but I was made a bit unsure by other threads. I have an earth bonding point on one of the very large engine bearers (I have a lister JP3). Here, all the earths come together - consumer unit, galvanic isolator, Viltron multi, and battery -ve, they are all within a few millimetres of each other and clearly visible. With regard to "The important thing is that the -ve is only connected at a single point so that a circuit through the hull is not possible (unless there's a fault)." I need to check my Genny but if its centre tapped, Then I will run an extra earth cable down to the earthing point on the bearer. Now this is where it gets a bit more interesting. As I have only one inlet socket, then only the shore line or the genny can be connected. so this could be either centre tapped earth or polarised I think you call it (shore line). Ok all fine up till now. When I fitted the Victron multi. I took the incoming mains out of the consumer unit and fed this to the Victron first (no RCD yet)! The output of the victron then goes directly to the consumer unit RCD etc. This then protects whether its shore line, genny or or inverter. The multi does the N-E bonding for the inverter. Now, this has left me a little unsure about the connection from the genny which has no RCD in circuit (the shore line does via the bollard). This really was the start of my thoughts about a PRCD next to the genny output to protect up to the domestic unit. The reason is that if the genny is in use and the RCD trips, then the line from the genny to the domestic unit is still live and could indeed be where the fault is - danger still present -am I correct so far?

I know there have been long long threads on RCD's bonding, inverters, gennys etc. but the one thing I struggle with is having a centre tapped source i.e. travel power or other portable generator and 0v earth N-E bonded mixed on a boat I understand the arguments and how/why it's done by keeping them as independant/separate sources but just doesn't seem right somehow. I have recently made some changes as I wanted to fit a Victron Multiplus and also a battery combiner Cyrix-CT. To do this I had to join the battery banks together (starter and domestic) on the -ves and take the +ves to the Cyrix. Whilst doing this I was recommend to earth bond the -ve to the hull, which I have done - is there any issue with doing this? (main reason for the Cyrix was to share the solar charge between the two banks of batteries while I am away from the boat (I don't like to leave the land line attached and Viltron running while away).

Thanks for the advice - much appreciated

Thanks for the replies as I understand it, it depends if the output of the generator is centre tapped or not (most floating portables are?) and if it is, then you can't connect N-E. The isolation transformer, would (I think!) supply me with an earth on the output (secondary) that I can bond the neutral to. Hope I am not confusing you and you see what I mean?

I know there has been a lot of discussion around portable generators and the problems of earth bonding and was just wounding if its possible to use an isolation transformer to save having to modify a floating output portable generator. The generator output feeds into the primary of the isolation transformer (floating) and on the secondary side (output), the earth and neutral are bonded (perhaps in the socket or plug)? Would this work? PS I am talking about a generator connection, nothing do do with a shore line connection.