[C320-list] Ground Bus Bar - Perkins M30 Alternator

[Bruce Heyman]

Hi Jack,
I would avoid adding additional ground wires without making sure you are not creating ground loops.   Some of the circuits on our vessels can involve very large currents.  Very small differences in the connectivity between grounds could lead to very large currents in wires not sized to carry the load.  The result could be an electrical fire.
Bruce

Bruce Heyman
bruceheyman at cox.net
(949) 289-8400
Somerset #671 San Pedro, CA
-----Original Message-----
From: C320-list <c320-list-bounces at lists.catalina320.com> On Behalf Of Jack Brennan
Sent: Wednesday, July 1, 2020 12:00 PM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Ground Bus Bar - Perkins M30 Alternator

Hi Jeff:

It sounds like a neat, orderly way to do it. A buss bar is a much better way to organize the wires. 

I would also connect the buss bar to the one behind your circuit breaker panel. I would need to dig back into my electrical books for a good explanation, but I believe having all grounds on the boat connected is strongly recommended. 

Jack Brennan
Sonas, 1998 Catalina 320
Tierra Verde, Fl.
Dolphin Cruising Club of Tampa Bay




Sent from Mail for Windows 10

From: Jeff Smith
Sent: Wednesday, July 1, 2020 2:19 PM
To: C320-List at Catalina320.com
Subject: [C320-list] Ground Bus Bar - Perkins M30 Alternator

To all with a Perkins,

Has anyone installed a ground bus bar for the M30 alternator? The common ground for the Perkins M30 is a bolt at the back of the engine. When I removed the bolt to ground my electric lift pump, I inadvertently severed three ground wires that were also attached to that point (alternator and something else I have not traced). My thought is to install a ground bus bar with one wire from the back of the engine and mount the bus bar somewhere close. Then I can simply connect my grounds on the bar.

Amazon sells a Blue Sea Systems Common BusBar (rated up to 250A, though I am looking at the 150A version), with 10 screws and a cover. I am curious if anyone has done something similar. I think I have at least five different wires grounded to the back of the engine.

Thanks,
Jeff
’94, #121