Myles,
The thought that electric boat conversion is a “job for the experts” never crossed my mind, so yes, you are wrong. Most of us “in the biz” spend far more time reading the various posts and learning from them than we do responding. I have personally benefited from numerous all postings, to varying degrees, and enjoy tapping into the tremendous ingenuity and creativity that exists out there, which as I believe it, is the entire purpose of this “discussion group”.
Every now and then a topic will arise which I (and others) have some unique experience with, electrical safety happens to be one that I take very seriously and have some relevant information to share. My boats have been sold to a broad range of people with different experience levels and I want to be as sure as I can that I did EVERYTHING I know I can to ensure that the boat was safe and reliable and strikes the best balance between those two. I know I speak here for my competitors as well. Most of your comments below are probably perfectly fine for Myles Twete and his level of general electrical knowledge but entirely unacceptable to my 79-year-old widow customer… I shudder to think what may happen if she were to use both hands (one at each end) of a cartridge fuse while the motor is jammed with weeds but still powered and accidentally introduces herself into the circuit. Fuses for home use are virtually nonexistent today for reasons more of general safety than any other, replaced by circuit breakers. Suggesting that fuses are cheaper which makes them a wiser choice doesn’t cut the muster with most people concerned about safety and the idea of someone jamming something else into a fuse receptacle under the lack of on-hand fuses is a thought which should keep me up at night.
As far as your situation with your clothes dryer I could tell of similar stories of chasing gremlins, but if you were one of the parents whose child was saved by the child protection lockout, you would have a totally different attitude about that innovation.
Clearly we have a difference in opinion as to what makes something safe and what doesn’t, the good news is that each of us are free to make the choices we feel we can live with. There is a wealth of good information available from organizations such as the SAE which we can all benefit from if we possess the right attitude. If that scares people away from converting their boats then they probably weren’t suited to be e-boaters in the first place, although I have great faith in those who monitor this site or contact us for off-line advice and doubt that any will be swayed away from electrics because we discuss safety.
Monte
From:
Sent: February 10, 2010 1:07 PM
To:
Subject: RE: [Electric Boats] (A Little) More On Electrical Safety...
I sense that this discussion is beginning to scare some folks away from converting their own boats---folks who don’t want complication, but do want safe and simple.
And given the 2 of you are both “in the electric boat biz” I can’t help but sense your point here is a bit like converting boats to electric is a job for the experts.
But I’m probably wrong.
A couple points come to mind with what I’ve read from you guys:
1) SAE: Society of Automotive Engineers ----- folks, SAE standards are not something that concerns electric boats. ABYC, sure, but not SAE.
2) Boat fires: sure, electrically-
3) Fuse vs Resettable circuit breaker: I’m with Arby on this. With a resettable breaker, when it blows, 99% of us would likely look around, check a few things, then just flip that breaker back ON. And if the controller or something else developed a short circuit, there’s a very high risk that the resettable breaker could weld shut. Sure, include an accessible main manual power disconnect in the system and put in at least one quick acting fuse per battery pack, attached very near or on the battery post. Do not get a fuse rated for much more than you expect to operate at max throttle. You don’t need to spend anywhere near $100 for such a fuse as the class T fuses I use can be had for under $20 each, some with holes that will slip right on a battery post. Worst case, if you blow a fuse and don’t have a replacement, in a pinch you can jump the fuse to get to safe harbor. But carry extras---I carry extra fuses, extra motor brush set and an extra controller--
4) Charging Interlocks: I dunno….sure, I guess. But be careful what you wish for in this regard. Imagine going to your boat and only wanting to demonstrate to your friend the power of the electric outboard. You don’t want to go anywhere and you leave all the lines and shore powered tied. You just want to demonstrate the pulling power and push a lot of water at the dock. You flip the switch---nothing. Scratching your head, you start checking or pulling fuses, checking wiring, cussing, etc. After about 10 minutes you finally figure out, oh yeah, I need to disconnect the AC power to do this. There are alternatives to charge interlocks including some that were proven a hundred years ago with electric car charging. My 1920 Milburn Light Electric car’s charge plug is a cylindrical coaxial plug designed to simply slide out the back if the car accidentally is driven away. I’m not advocating this here, but it’s funny how many modern electric cars choose the complicated (interlocks) over the easy solutions. Do what makes sense in your situation---
5) Worst Case: So your controller fries shut while you’re on the water and your circuit breaker also welds on---motor is now running full bore and you forgot to include a manual disconnect. This is a really bad thing for a car---but how bad is it really with our electric boats? I mean, really…these are boats, and in boats we generally stay far away from other boats and objects except when docking or traveling thru narrows or some sort. And instead of the capability of 60mph top speeds and 3000# as with perhaps the typical electric car, we’re talking maybe 6mph and 4000#, with the typical electric boat. This is 75x less kinetic energy we’re talking about here. Sure, you’ll likely have to think fast and decide a course of action, but unless you’re heading towards the dock or cannot maneuver around boats or people at that moment, you can likely run the boat like this until you either (a) burn thru the batteries’ energy in less than an hour, (b) manually remove one of the power cables from a battery and eliminate the hazard. Be aware of the possibilities here, develop a contingency plan and be ready to act.
I’m all for coming up with standards and adopting safety measures that make sense. But there are many options to achieving safety. A controller charging interlock sounds good, but without providing feedback to the captain (visual or audio) as to why the freakin’ boat motor won’t go when it’s locked out, the interlock could be almost as embarrassing and even tragic as forgetting to pull the plug in the first place. Some folks would start cutting wires and replacing motors before figuring out the interlock was the cause. Our new fancy electric clothes dryer has a freakin’ lockout----a child protection lockout. Well, having no children, we never paid attention to that feature until one day we accidentally got it in that mode. The manual didn’t make clear we were in that mode. Online resources didn’t shed light. Finally, a service call was made. The service man arrived and said for me to go get the operators manual, and when I came back he had the dryer running and pointed out the lockout feature. He wanted me to pay $80 for a service call. I refused and eventually got them to waive the fee, blaming the company for putting a lockout feature that didn’t adequately explain how to know you were in lockout. Bottom line: If you add a lockout, be sure to add a visual or audio indicator that lets you know what is going on.
-Myles Twete,
Just another electric boater: www.evalbum.
From:
Sent: Wednesday, February 10, 2010 6:47 AM
To:
Subject: Re: [Electric Boats] (A Little) More On Electrical Safety...
Ironicaly, SAE just released their new standard for electric vehicle charging protocol. The plug has heavy conductors for charging the battery string, and several light conductors to energize a relay in the charger, and signal the correct current and voltage. I own a copy of the standard (60+ pages) but it's locked, and I can only take screen shots. The plug and recepticle are being manufactured by several vendors, I'll try and list them.
A GFI breaker might be a solution. If over 50mA bleeds into the water, it'll trip.
Also of note: A 45ft yacht burned to the water last week, the result of an electrical fire. Most of the boats being converted these daze are 30 to 40 years old, and sport ancient shore power cords and connectors get even hotter with battery chargers refilling the acumulators. I now include replacing old crusty power components with new stainless ones. Freshness counts.
Be Well,
Arby
On Feb 9, 2010, at 5:55 AM, "Monte Gisborne" <emotive@xplornet.
Another point worth making about electrical safety is the extension cord used to tap into the shorepower outlet. If your boat does not have an interlock to immobilize the boat while under charge, it is quite possible for someone (never us; usually the dumb uncle or nephew who borrowed the boat without asking first) to leave the dock with the boat still on charge. The worst-case scenario here is that the live end of the still-plugged-
in extension cord falls into the water, creating a hazard which could cause serious injury to those nearby the dock, which is generally where people swim. The answer here is to make it so that if the electrical cord were to fall into the water, it would have to be dead, not live.
Few of our boats have the proper interlock which tells the motor controller not to energize as long as the batteries are under charge, so the simplest way to add safety here is to create the scenario that if the boat were to leave to dock whilst under charge, and the cord became taut as the boat moved along, the disconnect would happen at the dock side of the equation and not the boat side. This is usually done by simply attaching the short charger AC input cord to the extension cord by knotting them together or similarly. In this event, the cord falling into the water would not be live, a trick which is long-understood by many e-boaters and intuitive to many on this list but if one more person learns of this safety procedure it’s worth posting.
One of the features I like about the Delta-Q QuiQ chargers is that unlike almost all other chargers they provide the facility to disable the vessel during battery charge. However, this feature is only of benefit if the motor’s controller is set up to allow the input from the charger, which isn’t the case with most electric outboards. I have discussed this with Torqeedo, hopefully they will make the necessary modification to their products to take advantage of this interlock feature.
Off my safety soapbox for now, let’s enjoy some good, safe boating out there!
Monte Gisborne
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