Ring vs. Spade Lugs

[farotherside]

Ok - I gotta say, I'm a newbie boat owner, and am now a liveaboard on a 25-year-old, glass-over-plywood Brown Searunner trimaran. The learning curve has been steep, to say the *very* least. She needs a lot of work, and I'm doing it all myself, learning as I go.

...but now that I've reached the electrical systems, I'm breathing a huge sigh of relief - having been a network administrator for the past fifteen years or so, all of this stuff just makes sense. Finally! Something I already know how to do - or at least mostly, and I know where to look / who to ask when I don't. Hell, turns out I even have a friend who works at Xantrex.

Anyway. The previous owner(s) clearly wired the boat up over a number of years, and while they used nice components most of the time, the uh... shall we say elegance? of the installations leave a lot to be desired. I dunno, maybe "hunting camp chic" will be in next year.

For every. single. bloody. connection. they used crimped-on ring lugs, screwed into terminal panels with slot-head screws. Needless to say, there's at least twenty of the damned screws lost below holding tanks in the bilge now.

WHY did they use ring lugs?! Is there some "maritime" reason to use rings over spade lugs? I bought a pack of 200 spade lugs and a nice new set of crimpers today - unless someone says something to stop me, I'm going to cut every damned ring lug off tomorrow and replace them all.

What say you, forum?

[thinwater]

Originally Posted by drew23

Ok - I gotta say, I'm a newbie boat owner, and am now a liveaboard on a 25-year-old, glass-over-plywood Brown Searunner trimaran. The learning curve has been steep, to say the *very* least. She needs a lot of work, and I'm doing it all myself, learning as I go.

...but now that I've reached the electrical systems, I'm breathing a huge sigh of relief - having been a network administrator for the past fifteen years or so, all of this stuff just makes sense. Finally! Something I already know how to do - or at least mostly, and I know where to look / who to ask when I don't. Hell, turns out I even have a friend who works at Xantrex.

Anyway. The previous owner(s) clearly wired the boat up over a number of years, and while they used nice components most of the time, the uh... shall we say elegance? of the installations leave a lot to be desired. I dunno, maybe "hunting camp chic" will be in next year.

For every. single. bloody. connection. they used crimped-on ring lugs, screwed into terminal panels with slot-head screws. Needless to say, there's at least twenty of the damned screws lost below holding tanks in the bilge now.

WHY did they use ring lugs?! Is there some "maritime" reason to use rings over spade lugs? I bought a pack of 200 spade lugs and a nice new set of crimpers today - unless someone says something to stop me, I'm going to cut every damned ring lug off tomorrow and replace them all.

What say you, forum?

Spades have a nasty reputation for coming off. Amperage on boat circuits can easily start fires. This is not IT wiring.

IF you use use spade fittings, only those with flanged or "safety" ends are approved - not straight spades.

I hope the crimpers are an adjustable ratchet type by Ancor or Kline or someone notable. They are WELL worth it in ease and quality of work. Also, the crimp fittings should be the double crimp type - the length of the stem is longer.

Really, I suggest a book on marine wiring. There are many differences is in practice from home wiring, and even some from industrial wiring practice.

As for the slotted screws... as you know, very painful. Phillips to replace, and a magnetic tip on the driver.

Good luck.

[Christian Van H]

Do it and you'll be sorry. Best get a book on boat wiring. Nigel Calder's Boatowner's Mechanical and Electrical Manual: How to Maintain, Repair, and Improve Your Boat's Essential Systems comes to mind; Amazon.com: Boatowner's Mechanical and Electrical Manual: How to Maintain, Repair, and Improve Your Boat's Essential Systems: Nigel Calder: Books

Rings are the way to go. If you don't believe me, ask your surveyor, the guy thats gonna report back to your insurance company that your not up to code. Also know that your wiring should be tinned boat cable, and your ring terminals are best installed with adhesive lined shrink tubing for insulation... I wire elevators for a living, and they're no where near this well built. IMHO

[CharlieJ]

In general, ring terminals are preferred...they are not required by the American Boat and Yacht Council Standard E11. Locking spade terminals or flanged terminals are both satisfactory and in compliance with ABYC E11. Straight spade terminals are not permitted. I will use ring terminals in 95% of the installations I do (full disclosure, I wire boats for a living and sit on a couple of ABYC Standards writing committes) and only use locking spade terminals where removing the securing screw would be impossible. Speaking of securing screws; I agree that slotted screws have no place on a boat, especially in the electrical system. I routinely remove the slotted screws from the new, as packaged, circuit breakers and reinstall stainless Phillips head screws.

There is nothing in ABYC E11 that requires the use of tinned wire. Type II or Type III wire is required but the Types refer to the number of strands that make up the conductor. However; it is the marine environment and we are constantly fighting to get as much of the 12 volts available down the wire to do some useful work so do yourself a favor, and use tinned boat cable with 105C rated insulation (dry). Ancor and Pacer make this wire and it is marked every foot with BC5W2 and UL 1426.

Note that I referred to the ABYC "Standards". They are just that, nothing more. They are not a marine version of the National Electrical Code (NFPA 70). They are consensus derived standards developed and approved by the USCG, industrial representatives, and individuals that work in the industry. That being said, the Standards represent the state of the art in boat building and equipment and system installation and repair. The prudent Owner would be wise to ensure that the work accomplished on his vessel meets the Standards especially if there is ever an insurance claim.

Regarding adhesive lined terminations. I use them only where the conditons are, or could become, wet. Behind the panel board in a 42' sailboat, absolutely a waste of time and money. In the engine room of a 38' commercial fishing boat, an absolute necessity.

I second the comment on Calder's excellent book. I keep a copy in my truck and refer to it often.

[donradcliffe]

I say go for the spade lugs, except for the high amperage wiring where you are working with studs and nuts anyway. There is nothing more frustrating than dropping the little screw into the bilges when you are working with ring terminals. Even if some of the urban myths about spade lugs getting loose are true, your circuit breakers should prevent any fires. Full disclosure--I live on my boat, and don't believe that lawyers and their drivel should control my life.

[Cheechako]

The slot head screws on buss bars, breakers etc have been a bane to the industry for years, and they are plentiful in bilges for sure! The people who make these "special" marine appliances at high prices just cant bring themselves to pay an extra $.001 for phillips I guess.....

[Cheechako]

I finally took to cutting a small slot with dikes in the ring terminals so the screw didnt have to be removed. If you cut it just right, it kind of snaps over the screw diameter and works out well.

[Strygaldwir]

Ring terminals are such a pain, but I wouldn't have anything else on my boat.

Okay, so I do have them on the Danfoss Compressor and boy, am I sorry for that. I periodically (4 times in 3 years) have received an error code from the compressor that indicates a low voltage condition. All 4 times this has been traced to some type of failure at these spade terminals. They have always been the higher quality Anchor lugs, but corrosion, looseness, or once I don't know what it was, just replaced the whole wire, terminals and all. I haven't had this issue anyplace else on the boat (Okay, there was that one terminal to the autopilot) where there are ring terminals.

The strength of the connection assures that vibrations will not weaken the electrical and physical connection between the two devices. Well worth the headache associated with disconnecting the connection

[Badsanta]

Originally Posted by Cheechako

I finally took to cutting a small slot with dikes in the ring terminals so the screw didnt have to be removed. If you cut it just right, it kind of snaps over the screw diameter and works out well.

You can buy them like that. I have used all that I had and cant remember what they are called. Now I need more and cant find them. They worked great, just push it over the screw till it pops on. Wont fall out if the screw gets loose.

[thinwater]

Originally Posted by donradcliffe

I say go for the spade lugs, except for the high amperage wiring where you are working with studs and nuts anyway. There is nothing more frustrating than dropping the little screw into the bilges when you are working with ring terminals. Even if some of the urban myths about spade lugs getting loose are true, your circuit breakers should prevent any fires. Full disclosure--I live on my boat, and don't believe that lawyers and their drivel should control my life.

And so I keep some flanged spades around too.

And I used a lot of regular spades (thousands) at work and never had one come loose, but I like rings too, because...

It is also a pain when you go to add a wire or change something, and you can't get all of the spades to hold still! Rings can be simpler, too. It varies.

[CharlieJ]

Badsanta-The terminations that you are looking for are called locking spades.

[Badsanta]

Thats it! many thanks.

[anathema]

On anything that moves or can vibrate (This includes cars, boats-especially boats with motors!, vibrating industrial equipment, etc) ring terminals or at the very least locking spade terminals are the way to go.

Use the toothed part of your crimp tool to crimp on the terminals. This part of the crimp tool is indicated for non insultated terminals but I have been doing electrical work in VERY harsh conditions for some years now, and have never hear of one shorting out due to using this crimp. The connection is MUCH more secure.

In anything that can get Wet in DC you're in trouble anyways, but the best thing to do is to flow solder down inside the wire-holding part of the terminal after you have gently crimped it on. The solder will flow a short ways under the insulation and should keep you safe. I don't have a lot of salt water experiance, but I find that NOT covering it in any way which could hold water is better for corrosion than trying to cover it up. A proper soldered connector exposed to direct weather will still last a very long time.

[Cheechako]

Yea, be careful, your everyday cheap terminal crimper from the auto parts or hardware store does not work well. After you've spent all that time wiring you 'll start finding wire ends that simply pulled out of the terminal! You need the pro model or the kind that dont just mash the outside but push a divit into the terminal creating kind of a horseshoe shaped crossection.....

[anathema]

Exactly the ones I meant Cheechako