Re: [electricboats] Grounding.

Thanks John-

So, if we're worried about Myles making it home due to toasted electronics, I have most of you beat.  How many of you carry spare controllers?  Some of you maybe.  I do.

How many of you can drive your motor without a controller at all?  Only those of you, like me, with DC brush motors.  I've done it---back when I had a number of series connected golf cart batteries and no controller, I changed speeds initially by changing the connection to the battery string---using a jumper cable!

 

So, I have no worries at all that I'd be able to motor after a lightning blast, however, I'm guessing any blast that hit my boat and found a battery module would cause me to have to scramble to put out the fire.

 

Boat electronics or hull damage or sinking by lightning is about the absolute least of my concerns.  I could count the number of days annually that see lightning on just 1 or 2 hands here in Portland, Oregon.  And given all the other better days to be out boating, I might go 3-8 years without ever seeing a storm that could produce lightning within 20 miles of me and my boat.  In fact, in 24 years of mooring and using this boat now, I don't think I've heard thunder while out on the water but 5 times.

 

Everyone's equation, what they value and what risks they accept is different.  I'm good using a brush motor, lithium-ion batteries, a floating pack and no bonding to the water.  Seventeen years of electric-cruising and not having been stranded ever or having any critical issues/instances gives me little reason to change now.  Brushless motor is better?  Not if lightning takes out your electronics.  Oh, it's more efficient?  I get the same efficiency by dropping my speed by .02kt.  Lithium-ion too dangerous?  Don't use it then.  My bonding or grounding scheme doesn't match yours?  Maybe so, still doesn't mean mine is less safe.

 

Anyway, as I like to say, your mileage may vary.

 

-MT

From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of john via groups.io
Sent: Tuesday, December 8, 2020 8:49 PM
To: electricboats@groups.io
Subject: Re: [electricboats] Grounding.

 

The only thing that is a "given" is that lightening protection is not a clearly understood science.

 

Myles might be fine with his jumper cables - it just depends on how close and how direct a hit.  And if he's lucky and stays in the marina (away from Florida and Lake Michigan) when the weather is bad, his chances are MUCH better still.

 

Nevertheless - if he (or any of us) gets hit, with the jumper cables in the water - I'd still bet he'd lose most of his electronics.  If he's lucky, he'll make it home to tell the tale.  Though his beard (if he has one) might be a touch singed too...  <grin>

 

John

 

On Tuesday, December 8, 2020, 08:33:36 PM CST, Carsten via groups.io <carstensemail=yahoo.com@groups.io> wrote:

 

 

Please see attached table from DPWH Standard Spec 1109, Philippines.

That's their recommendations for a reliable ground cabling size for lightning protection of masts and constructions.

 

Myles, I guess that your jumper cable is not that size.

So your cable might only guide some of the lightning power away.

The remaining power will surely find another way, thus burning off your electronics, batteries, etc.

 

 

On Wednesday, 9 December 2020, 03:56:41 GMT+8, Myles Twete <matwete@comcast.net> wrote:

 

 

I have a jumper cable onboard…easy to throw one end overboard on that rare 1x/3yrs that I'm out on my boat, outside the covered marina in an active storm. J