Installation Frustration!

[Scott T-Bird]

Saturday I got a round to installing a galvanic isolator. Reading up on them, I'm not sure why I need it. My anodes don't seem to take much of a hit after 3 years experience. But I bought it, so what could it hurt, right? It's a ProSafe 30 amp model. Just connect 2 leads from the ground wire somewhere between the shore power connection and my new ELCI on the AC panel. BTW, I weighed the possibility of installing a Isolation Transformer & decided against the expense, since I bought and installed the ELCI first, and it seemed like overkill (maybe the GI is wasted money, too?)
The first part of the installation went well ... I located the loom that holds the Romex with 10 awg stranded wire conductors. It is conveniently located under the quarterberth and fastened right next to an opening with a cover. So I expose the Romex and slice it carefully to expose the conductors. I pull out the green conductor and make my cut so that I can attach ring connectors to each end. What I notice is water weeping out from the Romex shield. Eventually, enough weeps out that I can tell it is fresh water. After about an hour, enough weeps out to make a small puddle. I know that when buildings flood with salt water, all wiring that is exposed to salt water has to be completely removed and replaced. This left me wondering if I should really replace the cable run.

I'm pretty certain that the source of the water is merely leakage under the cover at the shore power connection. I'd bet that enough rain water has leaked through that junction to get into the Romex. There was no sign of water in the loom itself. It only weeped out when I sliced the shield and it continued to weep for about an hour, after which it seemed to abate. When I installed the ELCI at the end of the cable, I saw no evidence of water or corrosion. BTW, does it make sense that that the conductors could be stranded aluminum wire? I didn't even think to notice when I connected the ELCI but the ground wire appears to be aluminum, not copper. But I'm not really sure that I can tell, except that the stranded wire looked silver to me.

Mounting that box under the platform was not nearly as easy as it would seem, given there was barely any room for fingers to secure a lock nut or hold a box end, either - can't see a dam thing, either . Then, when it was finally secured, I attached the ground wire with ring connectors to each end. On one side, I didn't like how I allowed the wire to become twisted so I tried to loosen it and adjust it. No good ... the stud simply loosened. Not happy with that, I finally decided to remove the GI and see what is the problem. Thinking that I might have stripped something inside the GI by over-tightening, I removed the 5 small screws to take the cover plate off. As it turns out, inside the cover, the stud is simply secured with a single nut that also secures a ring connector for a wire lead that disappears into the guts of the GI - it's the same on both ends. The nut had loosened when I was tightening the nuts on the outside. With the nut loosened, the stud just turns. Well, it was easy enough to re-tighten the nut and put everything back together, but it left me thinking.

What if boat vibration loosens that nut inside the cover? What happens to the continuity? I know that the GI advertising says that continuity is guaranteed, but this seemed just too easy to disrupt it (if I did). I don't like the feeling that I may end up with a ground that is disconnected. How will I know if it happens?

It also seems weird to me that the continuity of the ground is now connected with what looks like 18 AWG conductors that link the studs on both ends into the guts of the GI. Does this make any sense? The ground is now 10 awg connected to a stud on each end of the GI, which is in turn linked to the guts with these two tiny wires. What am I missing? Is this hocus-pocus junk? Is the case transferring the ground (does that question even make sense)? The case supposedly does not need to be grounded and is supposedly safe.

I have photos, but did not think to take a picture when the case was opened. I have to go back and shrink the heat shrink anyway, so I'm not done with this. It only took me about 4 hours to do this installation (twice as it turns out - it will be at least 3 times by the time I'm really thru). I'm thinking that I might go back inside the cover and at least insert a split ring washer to secure the studs.

 

[Cowpokee]

I didn't even think to notice when I connected the ELCI but the ground wire appears to be aluminum, not copper. But I'm not really sure that I can tell, except that the stranded wire looked silver to me.

Scott those are most likely tinned copper wires. A process of applying solder to resist corrosion.

 

[Scott T-Bird]

Scott those are most likely tinned copper wires. A process of applying solder to resist corrosion.

It is the original wiring from 1984. When I installed the ELCI, the conductors 'appeared' to be in good condition, so I didn't give it another thought. During the period that we owned the boat from 2004 until 2016, we never even connected to shore power. I don't know how much A/C power was used during the 1st 20 years, but the boat did not have a charger or a water heater so it probably was not ever used significantly with shore power.

 

[dlochner]

The wires are probably marine grade tinned wire. The tin/solder helps to keep corrosion at bay. Marine wire should have finer strands than typical stranded house wiring so you can't really see the copper underneath the tinning.

The water inside the insulation jacket is probably coming from the the inlet. You could pull it apart and reseal every thing or replace it with a Smart Plug. At least with the insulation jacket sliced, the water can drain out.

Are the grounding studs insulated from the case? Do they have a plastic bushing?

Reading up on them, I'm not sure why I need it.

A GI doesn't really protect your boat from itself. It protects your boat from bad marina wiring and other boats that don't have a GI and are plugged into shore power. What kind of Anode are you using? Zinc or Aluminum?

 

[jssailem]

@Cowpokee struck gold or should I say “tinned” copper wire. (Romex and Aluminum wire are discouraged for boat use )
The afore mentioned ‘Romex’ is called
“Standard Tinned Triplex Boat Cable - Round - White, Black & Green Primary Wire Conductors”.

Wire with moisture in it has a festering issue. Possible condensate, bit more likely exposed to a surface leak that is finding it’s way under the cover.

 

[Scott T-Bird]

At least with the insulation jacket sliced, the water can drain out.

Are the grounding studs insulated from the case? Do they have a plastic bushing?

A GI doesn't really protect your boat from itself. It protects your boat from bad marina wiring and other boats that don't have a GI and are plugged into shore power. What kind of Anode are you using? Zinc or Aluminum?

That's what I thought, the drainage would be a good thing. There are no plastic bushings, just brass toothed washers. The outside section of the stud had 2 nuts and 2 toothed washers. In order of progression from the case outward it was toothed washer, regular brass nut, then I inserted the grounded ring connector, then the toothed washer and finally the outer nut. On the inside, I don't really recall. I think there was a toothed washer, ring connector for a small wire, then the brass nut - that's it. It seemed like that nut could loosen easily.

That's why I'm thinking the GI isn't really necessary. I have a zinc anode on the prop shaft, just ahead of the prop. So SS shaft and bronze prop. I was thinking that an aluminum outdrive would be most vulnerable. Since there are only a few sailboats with similar assembly around me, I don't know that I have that much risk. There were a few boats with outboards, but they typically have the drive shafts out of the water when docked - and those boats aren't connected to shore power.

 

[LeslieTroyer]

If your not going thru zinc’s it’s possible they are ungrounded. This can happen if you use Teflon tape around the threads of the zinc. Or if the HE has been moved from the back of the engine where it gets grounded thru the mount.

The GI protects you from other boats in the marina that may be poorly wired, it’s not to protect the marina from your boat.

Les

 

[Scott T-Bird]

This can happen if you use Teflon tape around the threads of the zinc. Or if the HE has been moved from the back of the engine where it gets grounded thru the mount.

No to the Teflon tape, but what is HE? Heat exchanger? Nothing has been modified on the engine.

 

[Scott T-Bird]

I think what I'm most concerned about is whether this GI is actually an effective devise or if it is actually a hunk of junk that may do more harm than good by installing it. Note my trepidation about the internal components! I've cut my ground wire in half to install it.

 

[dlochner]

I think what I'm most concerned about is whether this GI is actually an effective devise or if it is actually a hunk of junk that may do more harm than good by installing it. Note my trepidation about the internal components! I've cut my ground wire in half to install it.

They are effective and necessary if the boat is in a slip and on shore power.

A significant difference between boat AC wiring and land based AC wiring is the connection of the ground and neutral wires (green and white wires) at the service panel. Ground and neutral wires on a boat should not be connected. The ground and neutral wires in a house or shore side AC circuit are connected inside the service panel.

When your boat is plugged into shore power, the ground wire electrically connects your boat to every other boat in the marina or at least being served by the same service panel. The GI sort of breaks that connection. Sort of, because it blocks low voltage DC current that can be present in the ground wire. This prevents galvanic problems with other boats eating away at your underwater metals. However, the GI does not block higher voltage AC current, so your AC circuits remain protected via the ground wire.

Because the boats are connected via the AC ground, essentially a battery is formed between the underwater metals on your boat and some other boat(s). It is a small current, but enough to eat away the less noble metals on your boat. All this assumes that your boat's AC is wired correctly and the AC ground and DC negative are connected at the engine.

The sacrificial anodes, aka Zincs, protect your boat from itself. Same problem, different metals form a battery and get eaten away. The anode being less noble provides the electrons rather than something expensive like a bronze prop or more damaging like a bronze through hull. If your anodes are not being eaten away there could be several reasons, as @LeslieTroyer points out, the anode may be electrically isolated from the rest of the metals because of how it was installed or if the under water metals are not bonded to the engine then they are electrically isolated, or the zinc may have crusted over. One drawback to zinc is that it can form a hard coating that electrically isolates the zinc from the water so it is no longer effective. This is problematic in fresh and brackish water. The solution is to replace the zinc with aluminum.

The short story is, GI protect your boat from other boats, an anode protects your boat from itself.

 

[Gunni]

I had the ProSafe 60 installed because my anodes were eroding very fast. Your most vulnerable metal to underwater current seeking ground is your anode. And the galvanic isolator addresses that, and my anodes now last the entire season.

I would think that the New Jersey back-bay experiences frequent freshwater events and that will cause a zinc anode to salt over and become largely insulated. This past year the upper Chesapeake (above the Rappahannock) stayed mostly fresh due to above normal rainfall. We get much improved protection from aluminum anodes.

 

[Scott T-Bird]

@dlochner that was a really great explanation and answer, except it didn't really address my concern! Yes, it can be assumed that the AC is wired correctly and AC ground and DC negative are connected at the engine.
But here is my concern:
I've now cut my A/C ground in two. I now have to rely on this GI device and I have my doubts about the devise for a few reasons:
1. Those studs that penetrate the cover plates at each end don't seem to be secured to anything substantial. There is only a lone nut to hold them securely in place on the interior side of the GI case. My A/C ground wire is now secured to 2 studs where I question the integrity of the studs connection to the case. I now wonder if my A/C ground wire is going to provide any protection. I've cut it in 2 and now I have to rely on this GI devise to provide protection.

2. It appears that the ground wire is connected to the interior 'guts' of the GI with much smaller wires. They look like they might be 18 awg. Doesn't this seem odd? Where I once had a continuous 10 awg ground wire, it is now cut in 2 parts, spanned with tiny wires into the 'guts' of the GI.

As it were, it seems that I have pulled aside the curtain that covered the interior of this devise, and what I saw concerns me. I don't understand how I can be assured that it will provide the A/C grounding protection that I should have. What happens if those interior nuts come loose? How can those tiny wires that link my ground to the GI 'guts' be adequate? I'm trusting this product, but should I?

I understand the concept that the GI protects my boat from deficiencies elsewhere. Could there be a 3rd reason why the zinc doesn't show much corrosion? Perhaps there just isn't enough activity. Our dock and the docks next to me on one side are virtually empty. Most of the boats that are in our area aren't even connected to shore power. Only my dock neighbor's boat is continuously connected to shore power. Even I am mostly disconnected from shore power. I tend to plug in only when I'm there. Other docks that have boats connected are pretty far away … 50 yards at least and most much further. I've asked my neighbor about his zincs. I don't recall his answer except that it seems that he doesn't get much zinc corrosion, either, but he uses 2 zincs on his prop shaft. I've wondered about the hard coating. We are in brackish water for sure, but we do have crabs and jellies in our area. I just think that there can't be that much galvanic action to worry about.

 

[Scott T-Bird]

I had the ProSafe 60 installed because my anodes were eroding very fast. Your most vulnerable metal to underwater current seeking ground is your anode. And the galvanic isolator addresses that, and my anodes now last the entire season.

I would think that the New Jersey back-bay experiences frequent freshwater events and that will cause a zinc anode to salt over and become largely insulated. This past year the upper Chesapeake (above the Rappahannock) stayed mostly fresh due to above normal rainfall. We get much improved protection from aluminum anodes.

That is part of my concern, also. When I look at it at the end of the season, it does look more like it is salted over and insulated, not really degraded sacrificially.

 

[Scott T-Bird]

I think when I go back, I will have to open the case again and take photos of the interior to illustrate my concerns. I'm assuming that the product does what it is advertised to do, I'm just a little disturbed that it doesn't appear that the ground wire ends are actually attached to something substantial. That stud that you see on the outside of the case is simply a stud that hangs in space on the inside of the case. Just color me a little bit skeptical! One of the photos shows the 5 screws (one is behind the wire) that are removed to take the cover plate off. When you remove the plate, the whole stud comes with it. There is only a single tiny wire that leads back into the gizmo inside the guts.

 

[dlochner]

2. It appears that the ground wire is connected to the interior 'guts' of the GI with much smaller wires. They look like they might be 18 awg. Doesn't this seem odd? Where I once had a continuous 10 awg ground wire, it is now cut in 2 parts, spanned with tiny wires into the 'guts' of the GI.

As it were, it seems that I have pulled aside the curtain that covered the interior of this devise, and what I saw concerns me. I don't understand how I can be assured that it will provide the A/C grounding protection that I should have. What happens if those interior nuts come loose? How can those tiny wires that link my ground to the GI 'guts' be adequate? I'm trusting this product, but should I?

I don't think it is a big issue. The GI is there to block small voltage DC current, somewhere around 2 volts. In ordinary usage the ground wire does not carry any current, so that's not an issue. The GI is designed to fail if a large current passes through it, as would happen with a direct short. When it fails, it should fail safe, i.e. it no longer blocks the DC current but does allow AC to flow in case of a direct short to ground. It might be that in the case of a direct short, the metal case might become part of the circuit, and the circuit breaker at the power pedestal trips. The ground circuit would only be energized for a few milliseconds. The ELCI and GFCIs protect you against low current AC leakage, so there should not be any AC leakage to the GI.

Could there be a 3rd reason why the zinc doesn't show much corrosion? Perhaps there just isn't enough activity. Our dock and the docks next to me on one side are virtually empty. Most of the boats that are in our area aren't even connected to shore power. Only my dock neighbor's boat is continuously connected to shore power. Even I am mostly disconnected from shore power. I tend to plug in only when I'm there. Other docks that have boats connected are pretty far away … 50 yards at least and most much further. I've asked my neighbor about his zincs. I don't recall his answer except that it seems that he doesn't get much zinc corrosion, either, but he uses 2 zincs on his prop shaft. I've wondered about the hard coating. We are in brackish water for sure, but we do have crabs and jellies in our area. I just think that there can't be that much galvanic action to worry about.

If you were to open the box where the power comes off the grid and enters the marina, you would see two or three hot wires, connected to a breaker, a row of neutral wires and a row of ground wires connected to the neutral. It really doesn't matter where in the marina the other boats are as they are all connected at that point. The variable is the salinity of the water and how well it will conduct electricity, higher salt content means a better conductor and vice versa. If your marina is in a creek, the salinity probably varies with rain fall and tides.

This year, ditch the zinc and use an Aluminum anode. I've posted this photo before. They are all anodes (L to R: Zinc, Aluminum, Magnesium) that were in freshwater, the zinc was in the water for multiple years, the aluminum for one season and the magnesium for 2 seasons. All from the same boat.

 

[Scott T-Bird]

That sounds reasonable. I'm probably over-thinking my concerns (as usual ). My single zinc generally looks like the middle one at the end of the season. It would be interesting to try a pair of aluminum anodes to see if there is a difference. I assume that if I used an aluminum anode, it might corrode more, so using a pair might be the safer way to experiment.

 

[Davidasailor26]

Just to confirm, you did replace your anodes when you left the lake, correct? If you used zinc there they would have coated over and would stay that way now.

We used zinc in Forked River, probably slightly fresher water than where you are, and never had problems with them coating over. By the end of the season they always looked closer to the third of dlochner's pictures. Based on that it seems like either you have poor contact with the zinc or you're right and you're just in a really electrically sound spot.

 

[Scott T-Bird]

Well, now that we're more into a discussion of anodes, I probably need some clarification. I never used an anode in freshwater and never thought there was a need for it. Perhaps the shaft has suffered but there is no indication. Lee's Park Marina did not have any shore power slips, so I never had any concern for electrical current. There was no way to be electrically connected to any other boat.

My old Yanmar 1GM had a zinc but the YM Series Yanmars do not, so I don't have any on the engine.

Similarly, for the past few years, the only boat that could be electrically connected to my boat was my dock neighbor, but only when he was at the slip and only when I was plugged in as well. For more than 90% of the time, I'm not plugged in, and for 3 weeks in early summer, my neighbor is cruising somewhere else and his slip is empty. Then, by the end of September, I move to another location where nobody seems to be plugged in either. Long story short, I think it is very rare indeed when my boat is electrically connected to any other boats. It could be that the whole marina is on one service … I don't know. I know that they have numerous breakers for different sections. But the point is, I'm not plugged in for the great majority of time, so I'm not be electrically connected when I'm not plugged in.

So that leaves the most likely danger is the galvanic current between my prop and the shaft. I might be better off with an aluminum anode, but I think it is likely that there is just not much going on in the way of corrosion. I'd guess that if my zinc was insulated and ineffective I'd find the shaft to become damaged. It is cleaned each season before clamping a new zinc. The last few seasons, I've only been in the water for 5 months maximum. My guess is that there just isn't much anodic sacrificing happening, and that's why the zinc shows so little degradation.

 

[Gunni]

Don't know the composition of your prop shaft, but most boats now have some version of stainless alloy shaft and a bronze prop. Galvanic corrosion of the bronze takes the zinc out and turns the bronze pink and punky. Guy on my dock neglected his anode replacement regimen, got on his mobo, fired up his engines and spun both his props to the bottom. Hauled the boat to fix that and found his heat exchangers dissolved. He showed up a few months later with a whole new boat!

An aluminum anode is insurance.

 

[dlochner]

An aluminum anode is insurance.

Correction: An aluminum anode is very cheap insurance.