1987 MK 1 Electrical System Upgrade - Feedback Requested

[J_Sail]

Thanks - MaineSail. I recalled that open grounds on the source side would trip ELCI's, but when looking earlier this week could not find any documentation for them that supported my recollection. Now I know - they changed the design between ver 1 and 2 and updated the online documentation to eliminate the mention of the removed annoying functionality. 

Warning - techie stuff to follow:
Regarding your statement that, "A high resistance situation in a shore plug can create an imbalance which can also lead to nuisance trips." If the only issue was a high resistance in the shore power plug, one should just see a low voltage to the load. One explanation for a high resistance neutral causing a nuisance trip, though would be a pre-existing high-resistance leakage path from an on-board neutral to ground. That could be a poorly designed noise filter on a device, an leaky heater element that is close the neutral end of the heater element, or a leakage path from either the hot or neutral side of circuit whose breaker is off (opening just the hot side). If it was high-resistance and from neutral to ground it would normally not trip the ELCI. As long as the shore power neutral is in good shape, virtually all the current would go back via the neutral, the voltage across the leakage path is only a volt or so, and the ELCI would be balanced. With a high-resistance neutral, though, some of the current would be forced to return via the leakage path to ground as the voltage across the leakage path rises, and the ELCI would trip. That is the situation that my proposed test exposes. By artificially opening the neutral at the ELCI input output you put the full 120v line voltage across any leakage path and force it to be used as the exclusive return. If there is a path the ELCI would trip

[mainesail]

Thanks - MaineSail. I recalled that open grounds on the source side would trip ELCI's, but when looking earlier this week could not find any documentation for them that supported my recollection. Now I know - they changed the design between ver 1 and 2 and updated the online documentation to eliminate the mention of the removed annoying functionality. 

Warning - techie stuff to follow:
Regarding your statement that, "A high resistance situation in a shore plug can create an imbalance which can also lead to nuisance trips." If the only issue was a high resistance in the shore power plug, one should just see a low voltage to the load. One explanation for a high resistance neutral causing a nuisance trip, though would be a pre-existing high-resistance leakage path from an on-board neutral to ground. That could be a poorly designed noise filter on a device, an leaky heater element that is close the neutral end of the heater element, or a leakage path from either the hot or neutral side of circuit whose breaker is off (opening just the hot side). If it was high-resistance and from neutral to ground it would normally not trip the ELCI. As long as the shore power neutral is in good shape, virtually all the current would go back via the neutral, the voltage across the leakage path is only a volt or so, and the ELCI would be balanced. With a high-resistance neutral, though, some of the current would be forced to return via the leakage path to ground as the voltage across the leakage path rises, and the ELCI would trip. That is the situation that my proposed test exposes. By artificially opening the neutral at the ELCI input you put the full 120v line voltage across any leakage path and force it to be used as the exclusive return. If there is a path the ELCI would trip.

I should have been more clear on "a high resistance situation can create"...

When the plug or terminal gets so hot that it heats the wire and makes the wiring brittle near the plug it can create a neutral to ground leakage. This is something a regular 30A breaker would not notice and with current flowing on the green we now have an imbalance. Sometimes the melting on shore power plugs is not always visible and happens internally especially where the wires may be twisted around one another.....

An ELCI can trip where a standard breaker would not because on the source side ground and neutral are bonded at shore anyway.. With the high resistance in the neutral and the jacket damage due to melting current may begin to flow on the ground. I have had a few shore cord sets where I can actually measure continuity between neutral and ground with it unplugged. Granted IIRC these have almost always been in DIY installed replacement cord-ends rather than factory molded units but it could still happen...

Here is an example of where the high resistance caused the wire jacket to become very hot then very brittle and crack. This was a hot but I see it between neutral & ground too and that would not create a trip with a standard breaker but can with an ELCI. The Smart Plug eliminates this heating and high resistance that can lead to in-plug wire damage.

[Jon W]

Hi Folks,
   I was going to let this post drift off, but noticed over 1000 views the past month so thought I'd give an update. Very little progress made in February due to life and waiting for the battery temp sense wire from ProMariner.

To date:
   I've spent ~ 110 hours working on the boat. Nothing is straight forward the first time around. Required lots of decisions each
        step of the way.

   All in all 85 wires ranging in size from 16 AWG to 1 AWG have either been installed new, or existing wires re-routed, or re-terminated.

   Batteries are not connected waiting for the inspection noted below. Bilge pump is direct wired    to the reserve battery temporarily
        just in case.

   External regulator will not be connected until after the inspection and first start with the new system. Why – everything is new
        and want to limit problem areas.

   Powered up the AC system with new ELCI breaker. No false trips for heater or outlets with heat gun and work light switching on
        and off. Charger not turned on since batteries not connected.

   In the spirit of checking everything as I went, I found the Nav station desk bolts were about to fall off and 3 of 4 macerator
        pump mounting screws were loose. All are tight now.

   Attached pictures of the new Blue Sea panel (with ELCI breaker) propped in place for the photo with new teak fascia,
        SmartGauge and BMV-700 installed; back of the panel with it's wiring; plus a picture of the external regulator installed and
        waiting to be hooked up. It may look buried, but is very easy to get to and use the reed switch.

Next Step:
   Contact Alan Katz (a local expert here in San Diego), to have my work inspected before    connecting the house bank,
        programming the charger/SmartGauge/BMV-700 and first start up.

Jon W.

[Ted Pounds]

Looks like an AMAZING job!   

[Jon W]

Thanks Ted. I'm happy with the way everything turned out, but couldn't have done it without the help from all the folks on this great forum. Inspection is scheduled for the morning of March 25.    Jon W.

[Ekutney]

Jon,

I have been following this post very closely & plans to use much of what you have done as a template.   I"d suggest to provide as a project with lots of pictures.  Stu should recommend the best place to post.

I"d like to see lots of pics if possible.

Where did you mount hour battery charger, I plan to buy the same unit & am thinking of the best place to mount it.  I assumed it is close to your house bank but the Visio you provided shows it in the Nav Station Area.  A pic would be great if possible.

[Jon W]

Hi Ed,
    There is a photo of the battery charger installed on page 12 of this thread. The charger is mounted under the Nav Station desk on the vertical bulkhead shared with the hanging locker. It is out of the way when sitting at the Nav station, is easy to access, mounts vertically, and is well ventilated. The photo is taken leaning over the holding tank looking aft under the desk. In the photo you can also see that the wires run through the port bulkhead not the hanging locker.   Jon W.

[Ron Hill]

Jon : You did a fantastic job.  Congratulations, it looks VERY professional!!   

[Stu Jackson]

Stu should recommend the best place to post.

This has been a great thread.  I've put a link to it in the Tech wiki, under Electrical; Electrical Panel, Wiring & Lighting section.

If Jon so chooses, this could be a great start to developing a Tech Notes for publication in Mainsheet magazine.

[KWKloeber]

Not shown, do you

have a green bond wire on the cap bolt of the Hx?
have, nor not have the DC negative bus bonded to the AC ground bus? If so, I'd consider investing in a fail-safe GI so your boat isn't the sacrificial lamb of your neighbor's leakage. 
Now that you have an ELCI protected boat, the bond is unnecessary.

k

[Jon W]

Hi Ken,
I added a ground wire from the hx to the engine compartment ground buss when I did the harness upgrade. I did not connect the AC ground buss to the DC ground buss. I read somewhere that it was not necessary if using an ELCI main breaker.   Jon W.

[Ron Hill]

Jon : You haven't mentioned it, but the 1987 C34s did not come with a GFI 120/115AC receptacle/s for your shore power wiring.

I'd highly recommend that you add one or two.  The reason I said two is because I believe that the 1987s may not have been wired in a single run (like the 1988s and subsequent).   Anyway, Check it out!!

A thought

[lazybone]

That's sexy.  You should mount it on clear plexi.  Its a shame to hide it.

[Jon W]

Hi lazybone,
    I did get a few Tim the Toolman grunts out of it.

Hi Ron,
    I have a GFCI outlet at the Nav station with a nice LED feature that lets you know when it's on. There are two circuits run to the four outlets in the cabin/head. Both circuits are tied together at a dedicated outlet dual buss (the small one on the right in the photo above). The power to the dual buss comes from the GFCI so all outlets are protected. This is a simple arrangement, and the original way I found it. The down side is I can only have a few things on at a time to avoid tripping the GFCI. Something to address at another time if it's a problem.   Jon W.

[Jon W]

Wednesday afternoon the entire system was inspected by a local boat electrician named Alan Katz. The inspection went very well. We turned everything on, and it all worked like it was supposed to.

Unfortunately one of the 6VDC batteries in the house bank may be bad based on voltage spread compared to the other 3. So everything was turned off. Saturday morning I need to charge the batteries with the AC charger for a few hours, check to see what the voltage is for each of the four batteries, then call Alan to give him the results. Hopefully this turns out to be a non issue.

Saturday morning I will make the following corrections –
1)   Add an in line 10A fuse for the 12VDC outlet at the Navigation Station.
2)   Add a piece of MIL Spec heat shrink tubing to one of the battery negatives (I must have looked in there 100 times, but didn't notice it missing).
3)   Move the external regulator negative from the house battery to the negative busbar after the shunt.

When the 3 corrections are made, he'll sign the schematic. I've attached a copy of the schematic with the corrections for reference.

Thanks to everyone for the help.
Jon W.