NEMA 2000 electrical system

[naturewaterboy]

Does anyone have any experience with a NEMA 2000 electrical system? I have an old boat that I just ripped the old wiring out of (some burnt wires mixed in the bundle). Instead of rewiring and using what must be close to a nautical mile of wire, I came across a Lowrance system that is a single cable that everything feeds into - engine sensors - temp, oil pressure, rpm, etc. and also can plug in speed sensors, trim/tilt position, fuel flow, fuel level, etc. It looks very simple to wire - everything just tees in with what is claimed to be simple and inexpensive tees. Sure would making wiring my 34 ft. dual station, twin outboard boat much easier. Anyone know much about these?

[Pericles]

Here's a start. http://www.nmea.org/pub/2000/index.html

You should also read Nigel Calder's three articles in PBB starting:

http://www.proboat-digital.com/proboat/200510/ Networking
http://www.proboat-digital.com/proboat/200512/ Networking II
http://www.proboat-digital.com/proboat/200602/ See Shakeout

Good luck,

Pericles

[naturewaterboy]

Pericles,
Thanks for the links! They are some serious reading... I just read the first two of Nigel's articles. I definately want to put one of these systems in my boat, since I've ripped out all of the existing wiring, and all of the gauges I have are old. I am putting on twin Mercury Optimax engines - 2006. I don't know if they are setup for the Mercury SmartCraft system - but I think I'd rather have the Nema 2000 system....

[TerryKing]

Thanks for the pointers etc... I added the PBB articles references to the WIKI at: http://www.boatdesign.net/wiki/Onboard_Computers

The combination of bussed power systems and networked monitoring and control is what newer aircraft have been doing for a while.

Are any NMEA 2000 manufacturers saying they support the small builder or rebuilder? I was thinking they were only really talking to OEMs at this point. Does any manufacturer give information on using NMEA2000 in a refit?

I'm mainly working on NMEA0183 stuff right now because it's more approachable for DIY stuff, and there are many off-the-shelf instruments etc. that can be integrated. But CAN / NMEA2000 is a much nicer approach, long-term.

Please keep us informed of how this goes and what you learn. Please add to the NMEA2000 section of the WIKI. Eventually there should be a section in the Electrical Systems WIKI about bussed power systems, too.

I'm waiting for my tools/equipment to arrive in a couple weeks so I can start working on this stuff again, as I just moved to China.

[naturewaterboy]

I went to the shop that I'm buying some 1yr old used Mercury Optimax 225s from - they had on the shelf a Mercury Smartcraft engine monitor. It was the older system - cant remember the name of it, but the newer system is called Vessel view I think. It is not NEMA 2000 though. It wires into the engines computers - a computer to computer link. I need to find out more about it - I'd rather have a NEMA 2000 cause then I can buy stuff from any manufacturer and plug it into the network. I don't know if any device can connect to the Mercury engines and communicate on the NEMA 2000 bus. I'm going to look for this.

One place I did find surfing is Lowrance - I've had some sonars of theirs and I like their stuff. They also repaired a unit for me with exceptional customer service, so I hope their stuff will work for me. What they say on their website sounds like they are targeting the do it yourselfer - their website says "...multi-device data communications networking within easy reach of even smallest boats and budgets with the new complete LowranceNET™ system." They say that their benefits include simplicity, easy installation, versatility and ease of sensor/display/system expansion, excellent performance and amazing affordability. This sounds like just what I need, but of course what the salesmen say and what is reality are often two different realities.

[Pericles]

Also try Panbo. Here's one reason. http://www.panbo.com/archives/2007/0...going_red.html

Pericles

[fpmurphy]

It is important to understand that NMEA 2000 is presently a purely network standard for communications on a boat between the producers of information i.e. transducers, etc. and consumers of information i.e. multi-function displays, etc. whereas distributed power systems are designed to simply the electrical wiring (mostly DC but also AC) in a boat.

Unfortunately, the rate of NMEA 2000 compliant equipment appearing on the market is still fairly slow - especially for retrofitting to existing engines. And distributed power systems are all over the map with vendors making no attempt to enter the DIY or retrofit market.

[TerryKing]

Originally Posted by fpmurphy

..snip..Unfortunately, the rate of NMEA 2000 compliant equipment appearing on the market is still fairly slow - especially for retrofitting to existing engines. And distributed power systems are all over the map with vendors making no attempt to enter the DIY or retrofit market.

I've been thinking about what I'd do on these issues when I start a build or refit project later this year.

'Distributed power' to me implies two things:
- A Bus-structured power system in which one or more main wiring systems with large wire size and high-value circuit breakers are routed (probably aft-to-fore) in the boat.
- Networked Control and Monitoring of many power connections along that bus.

So, both the physically large power bus AND some networked control are combined in a 'Distributed Power System'. I think.

A 'power connection' device attached to the bus would provide power for some category of equipment, such as a refrigerator, a pump, a lighting section, etc. It would have remote control and monitoring capability, with on-off (probably including timed functions from the main onboard computer), and monitoring to show on-off state (On,Off,Overcurrent Tripped), as well as analog values for current and maybe voltage.

With the power and control both bus-oriented there would be a reduction in the number and length of wires in a boat, and easier modification and adding of new functions.

The ability to monitor and control power would enable more effective power-budget control in cruising etc...

I'll be looking at what might be done by the DIY'er over the next year or so, and trying some stuff out, so let's stay in touch here if you're interested.

There's a small start on the Wiki :
http://www.boatdesign.net/wiki/Main_Page
but there's a LOT to go.. Please contribute there if you can....

[Landlubber]

As in everything to do with a boat...KIS (Keep It Simple).

The old NMEA 0183 systems are very user friendly for almost any non tech head, the 2000 series for com data is very high tech and really is designed for OEM's.

I understand Nigel Calder wanting to play with his new toys, that is his game, and I have the greatest respect for the man, but having to repair anything to do with closed buss systems at sea is entirely another thing.

(On another note his book "Boatowners' Mechanical and Electrical Manual" is the only book I have ever read that I agree entirely with, well worth having for every new boat owner, should be made compulsory reading)

If you can call the local water tow truck from where you go boating, feel free to do so when it all fails to work, if not, then leave it to the "Big Boys", certainly in the short term as they try to sort things out. Like anything new, it really does take a while to make it reliable, mariners do not have the luxury of calling local help when all goes belly up, and it WILL go belly up, just a matter of time. The sensor wires used in can buss wiring cannot be jury rigged (normally) to handle any current situations (amps I mean), so if the computer operating system has a hickup (lightening anyone?), it is all over red rover.

Hey, boats operate in a salty, damp condition when things are bad, electronics are like magnets, opposites attract, so the lovely humidity and temperature controlled atmosphere where the compter was made is seeking revenge on its' makers. We all know how airconditioners dry up our nasal passeges, they are starving for moisture!

KIS and keep it afloat.

[TerryKing]

Originally Posted by Landlubber

As in everything to do with a boat...KIS (Keep It Simple).The old NMEA 0183 systems are very user friendly for almost any non tech head, the 2000 series for com data is very high tech and really is designed for OEM's.

When I worked in Broadcasting it was Keep It Simple, Stupid! I Second the Emotion, and the Logic too...

I am sticking with NMEA0183 for a while, for sure.. It's much easier to implement a sensor or few as a talker, with a microcomputer, and multiplexing several talkers to a listener isn't too much of a chore. And making DIY and manufacturer stuff interoperate is much simpler..

I have prototype code running that receives 8 serial ports and sends each message out one port, in a PIC 24F type micro. When my shipment gets here (soon, I'm told..) I'll have my gear, scope etc. and I can get back on this subject.

I'm looking forward to the smell of solder again...

[Pericles]

Nigel Calder's article entitled "Getting on the bus" describes a serious incident in mid Atlantic.

http://www.proboat-digital.com/proboat/20070809/

As I shall be self building my boat, I will incorporate the newest electronics, most probably Raymarine, so comms problems will be minimised. I am spoiled for choice as far as installers are concerned. I plan to video the total build.

http://raymarine.know-where.com/raym...ult&city=&zip=

Pericles

[naturewaterboy]

Thanks for the link to the article. Since I'm rewiring the whole boat, I need to wire up the engine and fuel gauges - this is a huge number of wires that will now be handled by linking the Mercury engine computers to a Smartcraft compatable display. Since I have two engines and two stations, this will save me a lot of time and wire.

The other wiring I need to do is the power supply wiring - that's where the distributed power bus comes in. I'll look into some of the brand names mentioned in Nigel's article. All I really want is to make the wiring simpler - the simpler the less there is to break. Running a big power cable from the batteries to the helm station and then a power cable back to a bilge pump back near the batteries doesn't make as much sense to me as running a control cable to a relay/circuit breaker located near the pump. Is this the way the current systems work?

[Landlubber]

You do not run a 2/0 battery cable from the batteries to the control station and back anymore (well since about 1975 anyhow). Blue Seas and BEP in NZ make nice marine solenoids especially for battery switching, you only run the sense wire to the helm, as you have basically suggested anyhow.
And as for bilge pumps, well they should not be switched through the battery switch anyhow. They run their own race and are remote from the normal boat circuit in anything over 25 feet. When you go home, switching off the batteries (and the bilge pumps) is not going to help if there is a leak.

[Pericles]

20 pages from Lowrance about N2K.

http://www.lowrance.com/manuals/File...173_112006.pdf

Pericles

[mydauphin]

Originally Posted by TerryKing

Are any NMEA 2000 manufacturers saying they support the small builder or rebuilder? I was thinking they were only really talking to OEMs at this point. Does any manufacturer give information on using NMEA2000 in a refit?

I am meeting with a couple of Nmea 2000 folks here in Miami this week, I hope to become distributor. It seems to me that any work unless it is a simple boat should be done in Nmea2000. The advantage are just too great to ignore and I dont want to waste time on Nmea 183 which is a serial interface system.