Breakers

[Riverguy]

Lou you answered your own question, go ahead and test the upgrade. Or ask an ABYC electrician to explain why not.
Recently read where tinned wire was not actually necessary but a requirement of ABYC.
I only care if my insurer cares.

Well, being an ABYC trained electrician I can tell you that neither ABYC nor the CFR has ever required tinned wire. UL-1426 (boat cable spec) does not require tinned wire either. Tinned wire is a really good idea in almost any marine context but is not and has never has been required by anyone.

 

[Riverguy]

Yet another misconception...

Re: "Interesting but you assume that residential breaker are all thermal which is wrong....My question was more about using DIN rail format...and they are basically cheaper that anything stamped "marine" while compliant to the exact same certifications."


Yes, DIN rail mount breaker panels can accomodate HM breakers and yes, HM breakers are (recently) available for residential use. Most of the newer French-built sail boats/cats I've worked on use DIN rail breaker panels but I have yet to see ONE that used HM breakers.

Your original question focused on the Ignition Protected aspect (UL-1500)..."So why is that the ignition protection is so important aboard?" and much of the following discussion was likewise focused on that (as well as other environmental considerations), but as I've laid out, IP is not the issue.

The marine shore power panels I install/refurbish/repair typically use Carling or Airpax HM breakers exclusively and YES, they are a PITA to work on -- I would much rather work on a DIN rail system, but DIN is so easy, I'm usually not needed ;-)

The problem with DIN rail systems is that it is just too easy to put in the wrong kind of device.

Re: "...they are basically cheaper that anything stamped "marine". That's wrong. Actually they are typically MORE expensive. This is because the market for residential HM breakers is TINY. HM Breakers are just not needed in the vast majority of residential applications.

Go ahead...try finding a two-pole 30A HM residential DIN rail breaker for much less than $34 (including overnight delivery for quantity one)...you'll be surprised. The 50A version is the same price. When I buy them wholesale (Carling or Airpax without the "Blue Sea Systems" markup), I pay even less -- about $23.

The other aspect is that the breakers you are talking about were not designed to ALSO be used as on-off switches on a regular basis. The Carling/Airpax HM breakers are rated for ~10,000 actuations, the Residential breakers are nowhere near that.

It's fashionable (and sometimes justifiable) to bash 'marine grade' components as mere marketing malarkey, but having been an Electrical Engineer in multiple professional contexts and having examined the ABYC, UL and other marine standards carefully I can tell you that most people who bash 'Marine Grade' simply don't know what they are talking about.

 

[Riverguy]

Moreover....if you read this you'll find that Residential Grade breakers of ALL types are of notoriously poor quality and are causing thousands of fires annually. Do you really want these on your boat?

https://ieeexplore.ieee.org/document/10021241

 

[Riverguy]

Speaking about non corrosive past, as I started this thread I am allowed to hijack it, what about dielectric grease? For me it is a very good way to prevent contact corrosion. What, you fellow TFErs, areb thinking about it? Are you using it ot not? If not why?
Any comment will be a stone added to the knowledge building!

When I am working on boats with solid copper 'romex', i use stainless steel ferrules (frequently used/required in industrial or data-center wiring) filled with dielectric grease before I crimp the ferrule to the romex. This allows me to use a standard marine-grade butt-splice connector to connect the romex to UL-1426 boat cable.

One should use dielectric grease anytime dissimilar metals are in contact. And, it never hurts to use it...

 

[Riverguy]

Copper-clad aluminum (aka CCA) looks just like copper until you cut through it. I believe you are thinking about 'tinned' copper, which looks shiny like silver (until you cut through it).

The reason tinned wire is so freaking awesome is that oxides of tin conduct electricity EXTREMELY well (as well or better than clean copper), whereas oxides of copper do not conduct electricity well at all. So, even when the tinned wire begins to oxidize, it's still a great conductor.

 

[Riverguy]

Great observations...

I read through this thread as a learning experience. Partway through, the OP clarified he was talking about DIN Rail breakers, not the standard Siemens/Square-D breakers so common at Home Depot. Also was not telling about solid core Romex but rather stranded copper.

Does your guidance hold for DIN rail breakers? While I wouldn't go that route on a yacht. I have to admit they are super easy and compact to use and install. I guess the question is are they thermal breakers as you suggest? Also, Blue Sea breakers are designed to provide both circuit protection and switching. Do standard US style breakers provide switching too? Do DIN Rail breakers? I have no idea.

Thoughts?

Peter

I've addressed these in my most recent reply to the OP...thanks!

 

[mvweebles]

I've addressed these in my most recent reply to the OP...thanks!

Apologies, but I missed it. Question was about DIN Rail breakers and stranded wire. Not household breakers and Romex.

Linked article was sort of interesting, but would have been more so if they had named names instead of shielding everything Brand X/14/etc. it gave me a problem without a solution.

How big is the problem? The conclusion of the article sums up - I would think this means half the houses out there are about to erupt in flames.

About half of the residential circuit breaker brands marketed in the USA since the 1950s have demonstrated a high rate of failure to trip properly on low to moderate overload. That finding is well supported by the available test data. No contrary test results have been uncovered.

That said, I found the general study even more reason to bug Blue Sea or other established electrical gear for boats vs cheap Chinese knock-offs.

At any rate, I was just trying to learn. The DIN Rail stuff is intriguing. Maybe not for recreational yacht panels, but as adjuncts like solar get added, might make a lot of sense. I just don't know if the concerns about household breakers carry over to DIN.

Peter

 

[Bmarler]

Peter,
I use din mount breakers a lot for the industrial control panels I build. I wouldn’t recommend using them as switches, like the blue seas ones, but they are great for supplemental protection.
If you need din mount breakers on a mission critical install, you should use hydraulic magnetic for that. They’re easy enough to source, and not horribly expensive.
I’ve seen a lot of din mount breakers in modern yacht builds, where there might be a touch panel interface, or other higher end switches or controllers to turn loads on and off instead of a main switch/ breaker panel. They can be sealed up in a gasketed box in the electrical space. Easy to access, protected from any exposure..

 

[SteveK]

Well, being an ABYC trained electrician I can tell you that neither ABYC nor the CFR has ever required tinned wire. UL-1426 (boat cable spec) does not require tinned wire either. Tinned wire is a really good idea in almost any marine context but is not and has never has been required by anyone.

OK, can you you say why welding cable cannot be used for battery wires?

 

[Comodave]

OK, can you you say why welding cable cannot be used for battery wires?

You can use it but it isn’t tinned and I believe the insulation isn’t up to specs. It is very flexible but I had some in a previous boat when I bought it and when I cut the end off the wire was all corroded. And the insulation was kinda gummy.

 

[SteveK]

You can use it but it isn’t tinned and I believe the insulation isn’t up to specs. It is very flexible but I had some in a previous boat when I bought it and when I cut the end off the wire was all corroded. And the insulation was kinda gummy.

There you have it. My current boat has/had welding cable and the surveyor said

Welding cable is not acceptable for marine use. The outer sheathing is not compatible with the chemicals in the marine environment (such as oil and water) and can swell when wet, the wire is not flame retardant and is not tinned, allowing water to wick up the cable and corrode the thinner copper strands. Welding cable does not comply with Transport Canada or ABYC regulations for small craft. Please refer to TP1332E and ABYC E11 for correct marine wire/cable requirements

"You can" and "not compatible" is "definitely maybe"

 

[jgwinks]

My 1973 Concorde has Square D style breaker panels for both AC and DC. I can understand using them for AC but DC too? To check I deliberately shorted a DC circuit and sure enough, the breaker tripped. So they do work for DC. The boat has two 30 amp inputs and I noticed that all neutrals for both inputs went to a single buss. Not unusual for a '70's boat. The DC panel, being an AC type panel, had busses for both ground and neutral, only one of which was being used. I moved it to the AC panel and separated the neutrals. Figuring out which neutral should go to which buss was quite a job and I didn't get it right the first time. They're 50 years old and still work fine but on this boat, like a house, every device has it's own switch and you don't turn stuff on and off with the breakers. You turn them all on and leave them that way unless they trip, so they've had relatively few switch cycles in that time. The marine type breakers would probably stand up better to constant cycling.

 

[Comodave]

My 1973 Concorde has Square D style breaker panels for both AC and DC. I can understand using them for AC but DC too? To check I deliberately shorted a DC circuit and sure enough, the breaker tripped. So they do work for DC. The boat has two 30 amp inputs and I noticed that all neutrals for both inputs went to a single buss. Not unusual for a '70's boat. The DC panel, being an AC type panel, had busses for both ground and neutral, only one of which was being used. I moved it to the AC panel and separated the neutrals. Figuring out which neutral should go to which buss was quite a job and I didn't get it right the first time. They're 50 years old and still work fine but on this boat, like a house, every device has it's own switch and you don't turn stuff on and off with the breakers. You turn them all on and leave them that way unless they trip, so they've had relatively few switch cycles in that time. The marine type breakers would probably stand up better to constant cycling.

A friend had a late 80s Trojan that had a Square D panel in it. All neutrals bussed together along with other wiring errors. He was tripping the breakers on newly wired docks so we had to rewire his panel to split out the neutrals. It wasn’t too difficult since they had used triplex wire. So it was obvious which neutral went with each hot. We had to add a second neutral bus bar. His boat was much easier than my then current boat which had all individual wires and we had to figure out which neutral went with which hot and that took several days to accomplish.

 

[Turtle Blues]

Riverguy,
Thanks for the effort in updating this thread. In the six years it has existed I have directed people to it countless times.
We have a bin full of old rusted out grey panels never intended for the marine environment. It is a good visual aid regardless of the breaker discussion.
It seems the French really started the Euro move to DIN rail systems. Not a fan but they are an inevitable reality. I just have to update my dinosaur brain to accept them. Find it difficult that the rail is typically mounted in the back of the cabinet with the control switches over them.
Give me visible, accessible, panel mounted Carling type breakers any day. That installation is approaching 50 years as the norm for most of the Taiwanese builds.

 

[mvweebles]

......
Give me visible, accessible, panel mounted Carling type breakers any day. That installation is approaching 50 years as the norm for most of the Taiwanese builds.

Vega Marine (predecessor to Willard) used what we now know as marine style breakers ("Carling" as you call them) in the 1961 build of the first Willard 36. Although materials have changed for the better over the ensuing 62 years, the overall style and electrical architecture is easily recognizable by modern marine electrical standards for 12/24 VDC systems. No idea what best practice might be for larger vessels that run a lot of 120 or 240 VAC.

As an aside, I cannot imagine what it took to source stuff like marine electrical components in 1961, though Vega was located in Costa Mesa (south of Los Angeles) so likely had good access to whatever was available. And I think about the early W36 owners who ventured down Baja at a time before there was a highway down the peninsula. VHF radio was new and relatively rare - even if a boat had it there was slim likelihood there was anyone to hear a call.

Peter

 

[Riverguy]

OK, can you you say why welding cable cannot be used for battery wires?

When people say "Boat Cable", there is a standard (UL-1426) that defines what "Boat Cable" is. It covers insulation temperature ratings, water and oil resistance, number of strands per circular mil, etc. etc.

There is no such standard for what is called "welding cable". I would liken this to the term "garden hose", you know what it's intended purpose is but there are no safety standards governing it's construction or reliability, or use in contexts where safety standards are important. If a garden hose blows up, it's not a problem unless you installed it behind drywall to supply your washing machine. Welding cable (also sometimes called 'hurricane cable') is like that, it's the 'Garden Hose' of wire.

That said, I've seen some cable sold as welding cable that was marked SAE J1128. This would be ok to use according to ABYC and the CFR, but MOST of what is sold as welding cable bears no markings whatsoever.

 

[Riverguy]

Please do NOT assume that a breaker is ok when 'tested' by shorting!

My 1973 Concorde has Square D style breaker panels for both AC and DC. I can understand using them for AC but DC too? To check I deliberately shorted a DC circuit and sure enough, the breaker tripped. So they do work for DC. The boat has two 30 amp inputs and I noticed that all neutrals for both inputs went to a single buss. Not unusual for a '70's boat. The DC panel, being an AC type panel, had busses for both ground and neutral, only one of which was being used. I moved it to the AC panel and separated the neutrals. Figuring out which neutral should go to which buss was quite a job and I didn't get it right the first time. They're 50 years old and still work fine but on this boat, like a house, every device has it's own switch and you don't turn stuff on and off with the breakers. You turn them all on and leave them that way unless they trip, so they've had relatively few switch cycles in that time. The marine type breakers would probably stand up better to constant cycling.

There are a couple of dangerous assumptions someone might make from reading your post, and my comment on "combined neutrals".

1) You cannot test a breaker with a short-circuit and conclude anything about safety of that breaker. Fires are not caused by short circuits. Fires are caused when a breaker rated for 15 amps (for example) fails to trip at 25 amps, overheats the copper and ultimately causes the insulation and nearby structures to catch fire. The "thermal" breakers we've been talking about here are sometimes also called 'thermal-magnetic'. In a thermal-magnetic breaker, the "magnetic" trip only happens during a short-circuit and typically this is at 5x to 10x the breaker rating. The critical trip is the "overcurrent" trip, which is driven by the 'thermal', should happen at no more than 125% of rated current (at room temperature) but might not trip until 2x or 3x rated current in cold temps or when it's of poor design.

JUST BECAUSE A BREAKER TRIPPED IN RESPONSE TO A SHORT CIRCUIT TEST DOES NOT MEAN IT'S PROTECTING YOU OR YOUR BOAT AGAINST FIRE CAUSED BY OVERCURRENT!


2) Any breaker designed and rated for both AC and CD will be labeled that way. Again, just because you could make it trip by shorting across it (with either AC or DC), this tells you nothing useful about the breaker's behavior in an overcurrent situation. Do not use breakers for AC and DC interchangeably unless the breaker is specifically labeled for the voltage and current needed.



3) Re: "The boat has two 30 amp inputs and I noticed that all neutrals for both inputs went to a single buss." It's likely that your boat was originally wired for a single old-school SS-1; 50A two-wire shore power system. It is, was and always has been OK to combine neutrals on any boat that has a >>single<< shore power inlet. As the SS-1 systems have almost entirely dissapeared from marinas in the last 20 years...what I see over and over again is boat owners that replaced their single SS-1 with a PAIR of L5-30 inlets without knowing that they now need to segregate the neutrals. The "right" way to do this is to replace the SS-1 with an SS-2 50A 250/125v (even if only one 50A "leg" is connected). Again, as long as the boat only has ONE shore power inlet, there is no issue having a single neutral bus. As an aside, that SS-2 50A shore power cable is actually good for 100A at 125V (or 50A per 125V 'leg') -- but because everything goes through the single inlet, there only needs to be a single neutral bus.