Question no:.... can't remember..... anyway GI/IT's

[Ex-Member]

Apologies that there are already various postings but I couldn't find what I was looking for.

 

I understand the principal of GI's & IT's and that, in an ideal world, the best solution is a portable IT albeit not the most practical. If I have read things correctly either are only really needed when connected to shoreline (read on if I've got it right) but, whilst an IT fitted inside the boat is more reliable it is also more costly and the length of connection cable from shoreline to boat is the problem area. So..... at last.. my question is I have found an 'in line' GI which is a short cable, 1/2mtr or so, which connects from the shoreline to your boat cable and therefore only the GI cable is the problem area.

 

If I am correct in the above has anyone bought/used one of these or am I wasting my time (and yours) as per....?

 

 

[nipper]

[Phil Ambrose]

Not sure what you mean by the cables being the problem areas.

You are assuming that you only need galvanic protection when connected to a shore line, however you do get stray 12v currents zipping about even when not on shore power. 12v will do as much damage as 240v

Phil

[mrsmelly]

 

Normaly I would agree but in this case I think its just a case of missing a new reciprocating waffle sprocket would you not agree?

 

Tim

[Boat&Bikes]

I use a G.I. that is connected into the shoreline cable, i think this is what you mean? It works i think... Did you buy that boat from ABNB ? If so was it fairly old with good hull condition, if so was it not using some kind of protection from stary electical currents?

 

Ian.

Not sure what you mean by the cables being the problem areas.

You are assuming that you only need galvanic protection when connected to a shore line, however you do get stray 12v currents zipping about even when not on shore power. 12v will do as much damage as 240v

Phil

Are you suggesting there is something that should be wired into a boat to protect it even when not connected by a shoreline cable? Edited November 1, 2016 by ianali

[Iain_S]

Not sure what you mean by the cables being the problem areas.

You are assuming that you only need galvanic protection when connected to a shore line, however you do get stray 12v currents zipping about even when not on shore power. 12v will do as much damage as 240v

Phil

 

And neither a Galvanic Isolator nor an isolation transformer will protect against those.

 

An inline G.I. will do the same job as a fitted one.

[MtB]

Not sure what you mean by the cables being the problem areas.

You are assuming that you only need galvanic protection when connected to a shore line, however you do get stray 12v currents zipping about even when not on shore power. 12v will do as much damage as 240v

Phil

 

 

Take no notice. Phil has a track record of talking twaddle where electrics are concerned.

[David Mack]

If so was it not using some kind of protection from stary electical currents?

 

You need to watch for stary electrical currents!!

[Ex-Member]

sorry if I have confused anyone with my question.... I am still in a steep learning curve. Yes the boat I am buying is from ABNB and, although it was built in 2002 and has no protection, it has virtually no pitting but the surveyor recommends fitting a GI. Problem is there is so much information on different sites and I am still ina steep learning curve.

[Phil Ambrose]

 

 

Take no notice. Phil has a track record of talking twaddle where electrics are concerned.

OK Mike, ref stray 12v current, it would appear that Safeshore Marine are blatantly telling porkies and have been doing so for years, perhaps you should be the one to report them to the ASA, no? I thought not. As usual you post without actually having anything positive to offer the OP.

Phil

[Tony Brooks]

OK Mike, ref stray 12v current, it would appear that Safeshore Marine are blatantly telling porkies and have been doing so for years, perhaps you should be the one to report them to the ASA, no? I thought not. As usual you post without actually having anything positive to offer the OP.

Phil

 

I have and they changed their add so they no longer said ALL boats needed GIs.

 

 

 

The cable between marina bollard just before the cable gets onto the boat will be protected by the RCD in the power post. If that connected its earth cable to the walkway (if the walkway is metal) only the walkway would be in danger of corrosion.

 

Once the cable is on the boat things maybe a little different in that a short circuit between the cable and the hull could well make the hull live but as clean water is not a very good conductor of electricity it might not trip the supply post RCD so hull corrosion may take place. Hence the advice to put and IT in an insulated enclosure just off the boat. However although this is absolutely best advice it comes from people arguing over very small potential fault scenarios.

 

On a practical level fit a GI on the boat as soon after the shore line socket as possible or if the socket is in an area protected from weather you could put it between cable and socket.

 

Having done that please make sure you have a good hull earth bond and a working RCD/RCBO. This needs a good neutral-hull bomnd if an onboard generator or inverter are permanently wired to the boats 240V circuits.

 

 

[nipper]

 

Normaly I would agree but in this case I think its just a case of missing a new reciprocating waffle sprocket would you not agree?

 

Tim

Waffle sprocket? Yes, of coarse!

 

Do you know that, having had a very hard day yesterday, all I could do, is to think of what forum he though he was posting on!

 

My sleep was ruined with thoughts of , did he mean to post on the Railway Forum, or was it the US Army forums. But, all the OP really needed was to mention the Waffle sprocket or maybe The Inclining Gibble and I would, of coarse, given the OP the correct answer!

 

Right, the suns shinning and I can now go and do some more proper cruising, complete in the knowledge that all is well with the world!

 

Cheers Tim

 

Nipper

[ditchcrawler]

 

 

Take no notice. Phil has a track record of talking twaddle where electrics are concerned.

careful, that may be construed as a personal insult and get the thread locked.

sorry if I have confused anyone with my question.... I am still in a steep learning curve. Yes the boat I am buying is from ABNB and, although it was built in 2002 and has no protection, it has virtually no pitting but the surveyor recommends fitting a GI. Problem is there is so much information on different sites and I am still ina steep learning curve.

I don't use a shore supply but to me if that inline one is completely waterproof that looks an easy way to go.