Bill & Judy Rouse <yahoogroups@...>
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Bill K and Pat,
I would never say that "I think Bill K's point is that he thinks Capt. Henri's original engineering was poorly done and left an unsafe condition with unprotected long wire runs."
I would not say anything like that for numerous reasons. I think you know why.
Since Henri Amel is not here to defend his decisions made many years ago, I will remind everyone that at the time these decisions were made they very likely conformed 100% with the regulations in force in Europe and conformed with the thinking at the time. Let's compare Henri Amel's engineering decisions to General Motors at the same time:
- Disintegrating plastic bumper parts
- 4-6-8 engines with 100% failure
- Gasoline to Diesel conversions with almost 100% failure
- Reduction of plasticides in paint which caused paint to fade in 6 years
- Plastic transmission parts which caused a new industry to emerge to repair transmissions
- Fiero & Corvair (one name says it all)
- Foam headliners which fell in 5 years
- Chrome coated plastic which lasted about 2 years
on, and on, and on.
Can one improve on yesterday's technology? Certainly!
Can one not understand decisions made yesterday? Absolutely!
Should one of us criticize Henri Amel? Never!
Anyway, this is my sermon for the month. I hope that you enjoyed it.
On Tue, Oct 17, 2017 at 8:39 AM, sangaris@...
Yes, that's why I thought Alan's adding the Blue Sea fuses at the batteries sounded wise. Btw, in my house the distribution panel is smack in the middle of the house which reduces the total amount of wiring. It does, of course, have a main service breaker at the external drop wire, analogous to Alan's Blue Sea fuse. Then there are separate fused disconnects adjacent to heavy loads like the A/C and hot water heater in addition to breakers for those at the distribution panel.
I think Bill K's point is that he thinks Capt. Henri's original engineering was poorly done and left an unsafe condition with unprotected long wire runs. Alan seems to have a good solution. And, while the new Amel centralized panel would meet Bill K's criterion, it is (likely) not fused close to the batteries, leaving the same risk of chafe and shorting in either the wires going to the panel or the wires going to the engine & generator
I do suspect that the industry will continue to modernize with Distributed electric systems and have not overlooked the risk of shorting in the long runs, although I haven't looked into it enough to know exactly how it is addressed.
, wrote :
Craig , Your original post seemed to support locating breakers far from the power source , however this post seems to acknowledge the protection offered by locating breakers as close as possible to the battery bank. You even pointed to boat that burned up cables as a result of a short . Now I must be missing something . When I build a house , I have 220v/ 200 amps coming through a wall , I locate the distribution panel as close as possible to where it comes thru the wall. The ele
ctric immediately goes thru appropriate size breakers and passes thru appropriate sized wiring on to outlets , pumps ,etc . In the event of a short there is little chance of the wire being overloaded . You do not use 14g wire with a 20 amp breaker ! In a house you would not run a 220v line to a laundry room and place the breaker on the wall behind the dryer. I have never understood the difference between protecting a boat vs. a house . But , maybe I am missing something, it would not be the first time.
From: sangaris@... [amelyachtowners] <firstname.lastname@example.org>
To: amelyachtowners <email@example.com>
Sent: Mon, Oct 16, 2017 9:34 am
Subject: [Amel Yacht Owners] Re: Distributed vs. Conventional Electrical Systems
That seems an excellent idea. I remember that in 2001 I totally redid SM Miss Lindy's wiring (don't recall the hull number) after it completely burned out for the third time. All the heavy cables in the engine room, from battery to starter to generator to main house feeds had melted solid. As I finished up I still had low volts from the engine to the battery. Traced it to the starting cables having chaffed about 12 inches down inside the PVC pipe from the battery to the engine (that was supposedly there to prevent chafe). Your solution would have prevented much heartache and expense.
Will be interested in Bill K's bounce. Perhaps the modern distributed systems do incorporate that.
---In firstname.lastname@example.org, wrote :
well said Bill,
BUT that's exactly what we have on our SMs....th
e anchor windlass, the genoa furler etc have the breakers at the "other end" of the cables that run from the house bank...and...on the standard setup, there are NO FUSES near the battery connections.
I've put large Blue Sea fuses in the battery compartment on each of my 3 banks of 4 6V series batteries to try to address these issues.
What have you done ?
I think you (and Amel in the "old days") are simply missing the point of circuit breakers. They are most certainly NOT there to protect the anchor washdown pump, or t
he thruster motor, or any other piece of equipment. There is nothing
a circuit breaker can do to "protect" the pump motor, or other device: If it shorts, it has already died! If, in normal operation, it draws too much current for the wiring to support, then the wiring is undersized.
Circuit breakers are there to protect the WIRING and prevent the catastrophic results that can occur if a short occurs ANYWHERE that overloads the wiring. This can occur from many faults, none of them likely, but all with disastrous consequences. Wire chafe is probably the most common cause on boats, but others happen. I'd guess loose connections are a close second.
Having a breaker at
the far end of the wire, away from the battery, completely misses the point of why it is there in the first place. In my opinion, if you have a circuit breaker at the point of use of the power, you might as well just replace it with a switch--it is essentially useless.
When I ran a service department for a large charter company, one of the annual safety meetings I ran for for my staff was to dead short circuit a 12 volt battery through 14 gauge wire. Watching solid copper wire burst into flame and literally explode was a sobering experience for people who could easily get into the habit of thinking "its only 12 volts." It really made the point about why fuses and circuit breakers were essential.
There is nothing at all wrong with distributed CONTROL of an electrical system. That is just fancy electronics. But... you can not "distribute" protection of the wiring. I have never heard a good reason to run long lengths of un-fused wiring on a boat--or anywhere else. It is just dangerous--and for absolutely no benefit. Dangerous overloads rarely occur because of equipment problems. They occur because of wiring faults. Do they happen often? No, not at all. But when they do, it is truly terrifying.
C-zone, Ocotplex, etc, a
re NOT wiring protection systems. They are not "circuit breakers". They are CONTROL systems. Very different animals.
I have seen several boat fires at much closer quarters than I ever hope to repeat, and most of them were electrical in origin, all from things that shouldn't have happened--but did.
Back Creek, Annapolis, MD
, wrote :
I'd always thought Amel was ahead of the curve with its Distributed Electrical System. That seems to be the direction the industry is going, now with solid state circuit breakers controlled through the NMEA2000 data network. Eliminates the large industrial style circuit breaker panels of yore and adds great flexibility. Check out CAPI2, C-Zone, Octoplex, etc. Seems Amel is going backwards technologically if they're centralizing. Let's see, your anchor washdown pump shorts and rather than it tripping an adjacent breaker it's got to overload a 15 meter long cable run back to the central circuit breaker panel. To say nothing of the excess wiring to give all equipment a "home run". Must be missing something in this discussion.
Cheers, Craig SN68 Sangaris