"Connect to Engine" instructions

[Boatnut]

Angela,

Can you call the manufacturer of the heat exchanger and ask them where they reccommend the wire be connected? I think we all could learn something here.

If they wanted it connected to the ships bond, it seems they would label it accordingly.

Given the generator is an electrical producing device, my bet is, it is a saftey ground to insure the HE is always at the same electrical potential as the generator engine. If there is no difference of potential, you will not get a shock by touching the the 2 pieces.

Please let us know if you get more info.

[REBrueckner]

"Hatt tied the bonds to the engines and generators and by default to the batt grounds, been that way on my boat for 44 years."

Hatt ties all dc ground toegther, all ac ground together, both usually via buss type connectors,and all the bonding system connections together, each system is kept separate. Then a single wire (cable) is used to tie all three together...typically at a single point on one of the engine blocks. This is and has always been ABYC standard.

A variation on this is a wiper connected to the propeller shaft and then tied directly to the bonding system,no the engine itself, usually in cases where the shaft is isolated from the engine...as via transmission oil, perhaps. Funny stuff happens in bonding systems because of all the moisture and metals and alternative conduction paths in salt water. Calder has a generally informative discussion on this.

"Most people do not use the pencil zinks as they turn to mush and plug the tiny tubes in the exchanger."

Don't know about "most people" but they sure do flake off and clog stuff. The only way I know to prevent that is the change them at a minimum once a year.


"If the gen is tied to the bond system the zinks tied to the bonding system the zinks tied to the bonding system should protect the gen."

It's very unlikely and hence DD and genny manufacturers uses pencil zincs at various engine components. You can check any component is protected by meauring the cathodic voltage with a voltmeter....typically you'll find about 0.8v (800 mv) or so on a shaft or thru hull, virtually nothing on the interior of an engine.....enough ions in water can't travel through impellers, small diameter hoses and so forth to provide internal protection.

[SKYCHENEY]

I sounds like Rsmith's 44 years without pencil zincs is a pretty good record. I'd go with the voice of experience before believing in the theory.

[Boatnut]

Angella, did you ever get an answer on this one? Inquiring minds are wondering LOL