NMEA 2000 Drop Cable

[med2463]

Installing Garmin GWS 10 wind sensor. Connector on drop cable is too big for hole in pedestal bottom to run wire into engine room. Anyone else have this problem? Waiting to hear from Garmin to see if can cut the connector off and then reattach it to the drop cable so can run it through the pedestal.

 

[Bill Roosa]

nutering is permissable

You can cut the cable and the splice it back on after passing trhough the hole. Be sure to leave a pigtail on the plug end so you have something to work with and preserve the ground sheath connection.

 

[Ed Schenck]

Interesting that they really do expect you to cut and splice. My JRC radar actually has that in the instructions. The scanner end of the cable has a plug that is so big it won't even go in the scanner let alone through the boat, out the transom, and up through the pole. My Nexus wind cable and some others warned against changing the length however.

 

[Bill1565]

I think we are gonna leave for Miami without the wind indicator. When we come back in March we can enlarge the hole in the cockpit sole if necessary. I want to also replace the 2 meter drop cable. What I want is a 6 meter drop cable so I can do all of the T connectors and power wiring outside of that itty bitty engine room.

This is our first NMEA 2000 network and we are getting smarter by the hour about it. Mary already spliced the instrument wire where it exits the mast, and the kit came with a field installable connector for the instrument, but this whole network thing is nightmareish compared to the old single purpose instruments.

 

[Snotter]

Splicing many cables requires butt-connecting small gauge wire. I wonder what Maine Sail and the rest of you do when wires are too small for the red butts. I wound up buying small-guage butt connectors from Allied. They look like little buttons and are crimped with pliers. They don't have heat-shrink but they do have dielectric grease in them. I wonder how long these connectors would last in a marine environment tucked away in a pedastal.

 

[tommays]

Your going to find they really don't want you cutting NMEA 2000 cables as to work in the first place if you don't do the termination resistors correctly it will bring down the network


Bluesea makes a nice fitting that will pass them

 

[Ed Schenck]

Really like my Nexus system. All the transducers have bare ended wiring making it really easy to run through the boat. I have the "computer" mounted on the inside of a salon settee. It is really just a junction box with an amplifier I think. Then all the instruments are daisy-chained out in the cockpit. Very simple. Wish the radar had been so designed.

Bill, how are you going to Miami? I guess there are four ways, the canal or Florida Bay or Hawk Channel or the Gulf Stream. I have only done Hawk Channel, once each way. But great sailing.

 

[Bill1565]

Not to hijack the thread, but we are going Florida Bay. Mary has a blog on grocery store access in SW florida, and she will be researching Marco I and probably Everglades City, Marathon,Key Largo and Miami Beach. BTW if you ever get the opportunity spend time in the Publix at South Beach. Humans Like something out of a Star Wars bar.

Mary has already started a blog for all you snow bound sailors. Hope she doesn't wave my scrw ups all over the net.

 

[Bill1565]

if you don't do the termination resistors correctly it will bring down the network

Wazzat? Termination resisors is not something we have learned yet. I was not planning on messing with the array of T connectors which say in Garmin diagams that they have Termination resisors at the un opened ends.

 

[Bill1565]

Splicing many cables requires butt-connecting small gauge wire. I wonder what Maine Sail and the rest of you do when wires are too small for the red butts. I wound up buying small-guage butt connectors from Allied. They look like little buttons and are crimped with pliers. They don't have heat-shrink but they do have dielectric grease in them. I wonder how long these connectors would last in a marine environment tucked away in a pedastal.

Mary tinned, twisted and soldered the 5 wires, taped the joints and foil wrapped the two pairs, then taped the whole mess, Bless her nimble little fingers.

 

[joker460]

You can cut and splice. Each wire properly soldered and shrink wrapped and shrink wrap the outside core.
Or
You could just use a new Nmea2000 connector.

I've done both and both work.

 

[Mike B1026]

Connectors

Those sound like the connectors that AT&T used on phone lines for many, many years. Since the wire and contacts are sealed inside, with dielectric grease, I would think they would be fine.

Splicing many cables requires butt-connecting small gauge wire. I wonder what Maine Sail and the rest of you do when wires are too small for the red butts. I wound up buying small-guage butt connectors from Allied. They look like little buttons and are crimped with pliers. They don't have heat-shrink but they do have dielectric grease in them. I wonder how long these connectors would last in a marine environment tucked away in a pedastal.

 

[med2463]

You can cut and splice. Each wire properly soldered and shrink wrapped and shrink wrap the outside core.
Or
You could just use a new Nmea2000 connector.

I've done both and both work.

Hoping that is true, but still waiting on Garmin to verify. Crummy to spend $1,000 on a unit and one connector keeping us from the install. Won't be using it on upcoming cruise.:cry:

 

[woodster]

Mary has already started a blog for all you snow bound sailors. Hope she doesn't wave my scrw ups all over the net.

i suspect she wont do that as far as i can tell she is very devoted and with devotion comes over looking ones screw ups with in reason lol.....you two seem to be a really cool couple....but if she needs some humor in her blog then it will be your turn to overlook the screw ups lol ....

regards

woody

 

[Don12364]

Once Upon a Time!

Boats were laid up for the winter, masts taken down and rigging preserved in boiled linseed oil.
Manufacturers of everything electric that was mast mounted presumed that this demasting was the norm and, because one was not expected to unlace the wiring right through the boat every time the mast was unstepped, there would always be a joint box or plug/socket somewhere near the mast heel.
Imagine a yard taking a mast down where there was no means of disconnecting all the cables.

So, unless the manual describes how, one may reasonably presume that the equipment manufacturer anticipated that people will make a removable (and waterproof) connection in every cable. Usually this is best made below deck in the headlining and through a waterproof deck gland.
Normally cables with individual wires only require a connector block or plug/socket. Co-axial cables (to antennas) need co ax plugs.
IMHO what nobody needs are butt joints though.

 

[Bill Roosa]

Snotter. it is called the western union pigtail splice. Been using it in place of crimp connections for small signal (go figure signal!) wires for a very long time.
Tommays. The terminal resistors are in the specially designed end plug you (duh) terminate the wire with. You only need the terminating plug at an end that does not have anything connected to it. The purpose is to keep the signal voltage pulses from echoing back along the wire. The wires are just wires and can be splices normally

 

[Bill1565]

Wow. That's a relief about the Terminal resistors. BTW my dad called it a "Telegraph splice"

I love this forum. We had Morgans before and their forum had fallen apart years before we bought our first.

 

[joker460]

Just thought of an another way that I have seen.

Just make up a female/male extension cable (cable and 2 connectors).

That way you don't have to cut off the connector (no warrenty issues), It stays inside the mast.

Just a thought.

 

[tommays]

I have done some 2000 work and the resistors placement depends on the network setup

A GPS puck only setup requires one 60 OHM and a true network a 120 at each end

 

[kenn]

Nice diagram, Tom. NMEA 2000 was supposed to not repeat the connection nightmares of 0183, but if the hardware permits the incorrect hookup you indicate, then they've missed the mark again

Donalex - yearly mast removal is the norm up here too but just about no-one seems to have the connections made sensibly. I've seen everything from flying twisted wire (yearly twisted and taped, then just yanked apart at removal) , to terminal strips, to mil-spec Amphenol connectors.

Back to the OP - yes it is possible to cut and then splice the NMEA 2000 cable. Well made, soldered Western-union splices then taped or tubed will work. For some it might be simpler to make crimped connections:

The first is a butt-splice, the second is a closed-end splice, which I like a bit better because you first twist the wires together, it's only one crimp, and it's easy to weatherproof by squirting 3M 5200 into the single open end. leave slack in case the splice ever has to be repaired or remade.

Regardless of splice type, it's best to locate the splice somewhere where you can always get to it. Never bury any interconnection in inaccessible places.