37c electric panel ground

[sandpiper10471]

From Jim Legere, 05 27 10, this thread, "Incidently, your AC system green wire should be tied in to the engine block ground too". The original doesn't have it. To me it makes no sense, but then all those green wire become redundant. This was the comment that go me going on this thread.
Incidentally, if using a drive saver, is there any point? Theoretically, nothing goes from the engine to water (earth if grounded, as in hit bottom lol) with that big hunk of rubber in there. Sure you can rig a jumper, but is it worth it? Another thing to maintain in an awkward place.

 

[Jim Legere]

ABYC Standards & Recommended Practices says:

To quote from ABYC:

E-8.5.3 The main AC system grounding bus shall be connected to
E-8.5.3.1 the engine negative terminal or the DC main negative bus
on grounded DC systems, or
E-8.5.3.2 the boat's DC grounding bus in installations using
ungrounded DC electrical systems. See ABYC E-9, DC Electrical
Systems On Boats.
E-8.5.4 There shall be no switch or overcurrent protection device​

in the AC grounding (green) conductor.

I believe the reason is as follows: the green wire in an AC system is supposed to be a "lifesaver" path to ground - in the event of an electrical fault, the current travels through the case (of say your battery charger) and through the green wire to ground (as opposed to through your hand and your body to some other ground path). I can only assume having the boat's green wire attached your DC ground/engine block, etc. is a belt and braces approach to ensure there is a path to ground even if the green wire on the shore power connection is broken. You raise an interesting point about using a "Drivesaver" type connection on the prop shaft and losing conductivity to the water. I suspect ABYC would want some other path to ground available (e.g a Dynaplate?). Anyway, that's what ABYC, not Jim, says.

 

[guidera48]

I too benefited from the pictures in the Owners Mods Page and got enought courage to tackle my rat's nest of wires. I am finishing the back panel on the boat and these are my new panels that will hinge out. I will post a Owners Project page when all done.

I re-used existing breakers, installed new LED on switches, LED also showing navigation lights on. Still need to back wire but it's getting there. So far I have about 100 in the panel.

Thanks for the ideas guys.

 

[Jim Legere]

Wow!

That's a very classy looking panel, José. How did you do the lettering - is it silkscreened on there? And your status LEDs for the running lights - are they wired so that you can actually tell if the lamps are working? (I understand that there is some kind of LED with current-sensing technology that allows this...)

Any way, GREAT JOB!!!

 

[Ed Schenck]

Hard to believe that Jose and I have the same year boats. My panel is nothing like that. But I don't find a need to upgrade, it does everything that I need to do. The wiring in the back is not the best but at the panel connections it is all quite solid and clean. I did run another #10 wire for DC because of the HAM radio. Also added a breaker for the A/C and a better ground. Otherwise it is stock.

 

[Jim Legere]

Ed, I am sure that Jose's panel is custom - he mentions reusing the old breakers. That and the fact his boat's name is on the panels.

I like that swing out arm you have your radar mounted on. I have often thought of trying to make something like that. Where did you get it?

 

[Ed Schenck]

Hi Jim, there are many online(Google "tv swing arm") but I think you have to go to a store: http://www.radioshack.com/product/index.jsp?productId=3115672 . You need to see if you can adapt the mount to your radar display. Mine was easy.

Now for an embarrassing admission. That display has been there at least six years. And there is a nice Garhauer pole solidly mounted on the stern. But the radome is still in the v-berth! I have never finished the installation due to time and technical constraints. Wiring from there to the pole is a nightmare. The cable is large and has to plug into the back of the display where there is already a large power cable. The worst part is having to cut the radome end of the cable off, then route it through the nav table, then back and up through the pole, through a tiny hole in the bottom of the radome, and then splice it all back together. If I had your money I would have hired it done years ago.

 

[guidera48]

I decided I needed to upgrade the panel so I first designed the panels with MS Publisher. Made a JPG and asked my local trophy shop to make them. 3 weeks later he advised me he could not do them. I checked with a second shop and 4 weeks later told me his machine could not read my file. It seemed that all they wanted to sell were bowling trophies. Now I am a firm believer in doing business in Main street, but it was time to go out of town. I found a company in S.C. named Panel Craft. www.panelcraftinc.com . I emailed my pictures and got a reply next morning from Kevin. He assured me that it was no problem. They made aircraft panels, machine panels and tools. I selected engravable plastic, but aluminum, brass and other metals and plastics were available for the panel.

They could have drilled all the holes and engraved the labels but I wanted to be able to replace the labels in the future without destroying the panel. So I opted for pre made labels from Blue Seas.

I converted the files from jpg/pdf to EPS so his machine could use them and 2 days later I had my panels. He even emailed me pictures of the panels beeing engraved by the CNC/laser machine. About 65.00 for all three. I re used the existing breakers and meters. I purchased 18 blue LED 12 v. from Ebay for about 4.00 and 8 red 110v LED from Blue seas, about 2.00 each. I also purchased 28 labels from blue seas @ 1.00 each. I had 2 custom labels made @ 5.00 each.

I used my old panel as a template and taped it over the new panel and drilled all the holes. It was not hard and the results look great.

I will be glad to help anyone that may want to design their panel.
Josephguidera@gmail.com

Now working on my radar pole/engine davit and nav table.

 

[sandpiper10471]

Jim - thanks for the info re green AC grounding. From what you quoted (electricity is gobbleygoop to me) it seems the panel may be grounded to the DC negative bus bar which with my new installation is really close. I don't like the idea of AC leaking into DC but I guess it is better than getting killed!

 

[Bill1565]

My AC system is separate from DC. I read somewhere, maybe Nigel Calder, that this is correct, that the green wire should only connect to the shore ground thru the 30 amp cable I never thought about the inverter green wire. Not a problem. PO left me with miles of #8 green/yellow striped wire that I can run to the engine.

 

[sandpiper10471]

Bill - having read Jim's briefs from the ABYC, are you now going to ground the AC panel? or just the perverter? In fact, has anyone grounded the green of the panel to the negative of the DC system? And assuming original locations of engine and panel, what size of green wire would be appropriate?

 

[Bill1565]

Yes, I will ground the panel. Surveyors around here are sticklers for ABYC. and Insurance Companys are just looking for ways to avoid payout. My inverter ( xantrex 2000sw) calls for a #10 green ground on the case. That presently runs to the green wire bus bar behind my factory panel. since I have #8 green, that is what I will use to connect the panel to the engine. I have a plastic pad in the shaft coupling, so I don't know how the engine is connected to the sea, but that is another story.

 

[Jim Legere]

More electrical gobbledegook

This thread has gone on longer than most, probably due to the interest in our aging electrical systems and many folks dealing with old wiring. When I renovated my 1983 H37C electrics a few years ago, I found a really useful excerpt of the ABYC Electrical Recommended Practices, which I have not been able to find on the web recently. Therefore I am attaching it for those who like this sort of gobbledegook.

Besides the AC System Green Wire Discussion, another interesting point is how far you can run an electrical wire without having a fuse in the line. The short answer is "not very far" When I rewired, I upgraded the size of the wires feeding the DC breaker panel and connected them directly to the "Big Round Red Switch" as my family refers to the battery selector switch near the companionway. Following ABYC practice, I installed an 80 amp fuse next to the battery selector switch on the line going to the DC panel. Inverters that are permanently installed is another area where ABYC is quite particular, as Bill mentions with his grounding scheme.

If you don't enjoy working on electrical systems...don't! Get a qualified marine electrician to help. Although 12 volts DC isn't dangerous from an electrocution perspective, big batteries & big wires = big currents = burns and fires in the event of a short-circuit. MAKE SURE YOU ARE WORKING SAFELY with your boat's electrical systems!