wiring on an anode

[chrisarvor]

can anybody tell me where the wires on an anode come from?
i have traced 2 back the fuel tank brackets but what would the usual wiring be?
thanks

 

[mercman]

all wiring will go to an earth.whether it be a negative bus bar,the negative on the battery or on an engine stud.

 

[mercman]

what boat is it

 

[chrisarvor]

an arvor 25

 

[mercman]

whats the trouble can you not see the wires and where they go or you want to know what type of wire it is?
Have you asked essexboatyards for assistance

 

[jeffro]

I havnt wired mine an its been there for five years now on my third engine

 

[john_morris_uk]

IMHO disregard the comments about going back to an 'earth'.

The anode should be connected to any underwater fittings that you wish to protect against electolytic action. These are usually the propellor/shaft and sometimes include the rudder fittings.

Some people include all the seacocks, but if these are of good quality bronze and not connected electrically to other items underwater then this is not usually necessary.

One essential part of the system is that the anode must be able to 'see' the items that it is protecting - or at least be fairly close to them.

 

[chrisarvor]

i noticed my anode was not working and struggled to get my head in behind the fuel tank and saw the fuel tank fixing screw had fell out and two earth wires in mid air. so i connected the wires to the fuel tank fixing and hopefully it will now work.
i was curious to what wires should be on there .

Mercman have you got an arvor?

 

[mercman]

no but am good friends with the lads at essex and done work on arvors for them.mainly on the nanni engines. IMHO every installation on almost every boat the anode bolts have gone to an earth.Also the sea cocks as said. But even the good quality valves have been known to go again good practice to earth up.
I.e an outdrive anode is bolted to the drive and that component has a bonding wire (for continuity) to the next component right the way back to the engine earth bolt

 

[mercman]

mr morris if you bolt an anode to the prop shaft is that not earthed by the coupling on the shaft and the gearbox coupling???and this is bolted to the engine???
Point taken if an R&D COUPLING IN THE MIDDLE BUT AGAIN THESE HAVE STRIPS THAT TOUCH THE BOLTS AS THEY CROSS OVER

 

[john_morris_uk]

Don't know what you mean by 'earth'

If you mean the negative side of the battery? - which often includes the engine block etc etc, then I appreciate that many cathodic protection systems connect the anode to this point. BUT not all do, and not all should.

For instance on my engine (a Volvo 2040) the engine is especially electrically insulated from the gearbox etc. This is because in some fits, (for example, aluminium/steel and and other metal hulled boats) you might want to make sure that the negative of the battery does NOT connect to the metal hull.

I still maintain that in many installations there is no reason to connect the negaitive (which you call earth) to the anode.

An anode on the propshaft often offers excellent protection of the propellor and has an immediate and obvious electrical connection.

In response to your comment about couplings making electrical connections. Some do and some don't. I've had both. In some installations I've had to wire a braid across the coupling to ensure electircal connection. In some I've not wanted the electrical connection and have made sure I used an insulated coupling.

Anyway, my basic point is still valid. Connecting the anode to the negative line is frequently the practice, but is often not necessary. Just make sure that what you want protected is connected appropriately. I might add that we will get into the realms of stray currents accelerating electrolytic action soon!