Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 20-05-2022, 18:05   #1
Registered User

Join Date: Oct 2019
Location: Seattle, WA
Posts: 6
Alternator Ground - Best location?

reetings all,

I've appreciated all the information and wisdom on this board over the years.

Recently I've used it to help figure out the best way to upgrade systems prior to adding solar and Lithium Batteries.
I am ready to start the installation of a 150A Balmar Alternator, Regulator and Pulley Kit along with a Victron Orion DC to DC charger for the starter battery.

I will upgrade wiring, add fuses, and eliminate the old Battery combiner and the Digital Echo Charge.
I plan to wire directly to the House batteries from the alternator.

Where should I run this ground to?
The ground from the Alternator is undersized so I will upgrade this as well. It currently runs to a ground point, along with some other connection on the engine block about 16" away. Then a larger wire runs to a Ground block near the battery switches and then it connects to the ground switch where it also connects to the house bank ground here.

It seems like there are a few options:
1 - Stay on the engine block terminal
2 - Go to the House bank ground terminal on the Shunt about 5' away?
3 - Go to the ground black about 15' away?

What do you suggest for best performance and safety?

I spent hours today chasing and following wires to understand the system and I think this is the last question to answer before digging into the installation. Any other advice on the project is welcomed!
SeattleBuddy is offline   Reply With Quote
Old 20-05-2022, 18:51   #2
Registered User

Join Date: Jan 2014
Location: Panama City FL
Boat: Island Packet 32 Keel/CB
Posts: 975
Re: Alternator Ground - Best location?

I think sharing a single large engine ground (battery negative to block, starter, alternator, instruments, ect) is a electrically reasonable and cost / resource effective solution. Using a single shared conductor is done all over electrical/ electronic systems (circuit board traces and wire). There are cases where this is a bad idea but not typically.

Size it according to starter requirements. Modern alternator controllers typically don't even start ramping up the current until long after stsrting.


Frankly
Frankly is offline   Reply With Quote
Old 21-05-2022, 04:49   #3
Registered User
 
Fishspearit's Avatar

Join Date: Jan 2006
Location: FL
Posts: 592
Re: Alternator Ground - Best location?

Quote:
Originally Posted by SeattleBuddy View Post
Then a larger wire runs to a Ground block near the battery switches and then it connects to the ground switch where it also connects to the house bank ground here.
What do you mean by 'ground switch'? You should only be switching the positive side. You just want one ground terminal on your engine (put the alternator neg. here) and that should go straight to the negative side of your house bank.

Make sure your ground wire can handle the 150 amps that the alternator can put out.
__________________
www.BestMarineSurveyor.com
Fishspearit is offline   Reply With Quote
Old 21-05-2022, 04:52   #4
Commercial Member
 
CharlieJ's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: St. Petersburg, FL
Boat: Gulfstar Long Range Trawler; 53'; BearBoat
Posts: 1,368
Re: Alternator Ground - Best location?

OP:
I disagree with @Frankly Post #2: The starter is a load and it is the only circuit on board that is not required to be fused. The alternator, on the other hand is a source and its output is required to be fused at the battery. Therefore, Option 2 is the best option.

Ensure that the alternator B- is properly sized and is landed on the low side (system side) of the shunt. Only the B- from your house battery bank will be landed on the high side (battery side) of the shunt.
__________________
Charlie Johnson
ABYC Master Technician
JTB Marine Corporation
"The Devil is in the details and so is salvation."
CharlieJ is offline   Reply With Quote
Old 21-05-2022, 16:10   #5
Registered User

Join Date: Oct 2019
Location: Seattle, WA
Posts: 6
Re: Alternator Ground - Best location?

Charlie, Thank you.

The plan is for the Alternator to be fused at the battery with a 200A Fuse.
You suggest taking the ground going directly to the Battery which is not much further than the block. I just wanted to make sure this was typical and safe, vs going to the Ground Block, which in my case is much further away.
Thanks!
SeattleBuddy is offline   Reply With Quote
Old 21-05-2022, 16:13   #6
Registered User

Join Date: Oct 2019
Location: Seattle, WA
Posts: 6
Re: Alternator Ground - Best location?

Fishspearit:

Yes, there is a factory-installed ground switch.

For some reason the grounds are connected to a switch, the same design as the house and engine switches, just black vs red. I don't understand why it's there either. Maybe for some safety reason. I will upgrade to a 1 or 2 wire for both + and - to the battery.
SeattleBuddy is offline   Reply With Quote
Old 22-05-2022, 01:42   #7
Registered User
 
Searles's Avatar

Join Date: Feb 2020
Location: Port adelaide south australia
Boat: Cheoy lee perry 48
Posts: 389
Re: Alternator Ground - Best location?

Are you talking d c negatives or earthing I e grounding neither should be switched .⛵️⚓️
Searles is offline   Reply With Quote
Old 22-05-2022, 08:59   #8
Registered User

Join Date: Oct 2019
Location: Seattle, WA
Posts: 6
Re: Alternator Ground - Best location?

Searles, the question here is regarding just DC negatives.
SeattleBuddy is offline   Reply With Quote
Old 22-05-2022, 22:04   #9
Registered User

Join Date: Oct 2018
Location: Toronto, Ontario
Posts: 2,686
Re: Alternator Ground - Best location?

Quote:
Originally Posted by Fishspearit View Post
Make sure your ground wire can handle the 150 amps that the alternator can put out.
Quote:
Originally Posted by SeattleBuddy View Post
The plan is for the Alternator to be fused at the battery with a 200A Fuse.
What does Balmar recommend for circuit protection? Use Balmar's specs or if anything goes wrong, the warranty will be void and/or the manufacturer absent liability.

Does anyone else think that a 200A fuse sounds like too much?

Also, as Charlie says, the size of your wiring needs to be factored in. Wire size will be dictated by the distance from the power source - according to ABYC standard.

Fair winds,
LittleWing77
LittleWing77 is offline   Reply With Quote
Old 23-05-2022, 00:40   #10
Moderator and Certifiable Refitter
 
Wotname's Avatar

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 14,920
Re: Alternator Ground - Best location?

Quote:
Originally Posted by LittleWing77 View Post
What does Balmar recommend for circuit protection? Use Balmar's specs or if anything goes wrong, the warranty will be void and/or the manufacturer absent liability.

Does anyone else think that a 200A fuse sounds like too much?

Also, as Charlie says, the size of your wiring needs to be factored in. Wire size will be dictated by the distance from the power source - according to ABYC standard.

Fair winds,
LittleWing77
The circuit protection is for the wire with the battery being the source. The alternator being in essence a regulated voltage output limited current source should not need any circuit protection if the wire is correctly sized.

200A fuse (located near the battery) is not uncommon.
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is online now   Reply With Quote
Old 23-05-2022, 04:49   #11
Registered User

Join Date: Oct 2018
Location: Toronto, Ontario
Posts: 2,686
Re: Alternator Ground - Best location?

Quote:
Originally Posted by Wotname View Post
The circuit protection is for the wire with the battery being the source. The alternator being in essence a regulated voltage output limited current source should not need any circuit protection if the wire is correctly sized.

200A fuse (located near the battery) is not uncommon.
Thanks Wottie.

I was installing some batteries for a large genset last week that had 160-amp circuit protection, so I was just thinking about correct options.

When we were taught alternators, they emphasized (like FishSpeirit) that the conductors be capable of carrying an alternator's output and what you said - that an alternator is essentially self-regulating - it will only ever put out what it's rated for, i.e. a 150-amp alternator will only ever put out a maximim of 150-amps.

Maybe I need to go read the Balmar manufacturer's specs myself!

As always,
Wottie-is-King
Madame President, Wotname Fan Club
(aka LittleWing77)
LittleWing77 is offline   Reply With Quote
Old 23-05-2022, 05:09   #12
Registered User

Join Date: Oct 2018
Location: Toronto, Ontario
Posts: 2,686
Re: Alternator Ground - Best location?

Okay Wottie,

I took my own advice. Here's what Balmar stipulates for their alternator installations:

GROUNDING
Alternator models designated as Isolated Ground (IG) feature an independent ground terminal that’s isolated from the alternator case. Isolated Ground alternators are used in applications where the engine is not desired to be a part of the grounding system. This is commonplace in steel or aluminum hull boats, or with engines that depend on sophisticated electronic ignition systems. In other applications, isolated grounding simply ensures that the alternator is sufficiently connected to system ground. The alternator’s ground cable should be the same size as the alternator’s positive output cable.

FUSING
The American Boat and Yacht Council (ABYC), in its standards for safer boating, recommends that cable runs to your battery banks be fused to protect the boat and owner against damage and injury. Circuit protection, as described by ABYC standards, can be accomplished by installing either a resettable circuit breaker or a fuse. The fuse or breaker you choose will depend on both the amperage rating of the alternator and the size of cable used. The following considerations can be used to determine fusing:
  1. The largest available circuit protection device smaller than the amperage capacity of the cable being protected.
  2. Larger than the maximum continuous current that will flow in the circuit. We find that a circuit protection device sized at approximately 140% of your alternator’s rated amperage is typically suitable for the circuit being protected. For more info about circuit fusing, see http://circuitwizzard.bluesea.com
So according to Balmar 200-amp fusing is just about right (it's a little less than 140%).

I've also attached the Balmar alternator's Owner's Manual so our OP can verify.

Good luck, Seattle!
LittleWing77
Attached Files
File Type: pdf SUP-0207-REV-E.pdf (1.81 MB, 5 views)
LittleWing77 is offline   Reply With Quote
Reply

Tags
alternator

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Negative Ground vs Positive Ground History Question. Wotname Electrical: Batteries, Generators & Solar 23 26-04-2021 04:22
9 V difference between ground and ground Arrandir Electrical: Batteries, Generators & Solar 12 19-07-2018 22:51
Location of ground wire - Volvo Penta MD7A wcg78613 Electrical: Batteries, Generators & Solar 7 26-11-2016 16:20
To ground or not to ground an aluminum arch...that is my question. chrtucke Electrical: Batteries, Generators & Solar 9 06-10-2014 23:17

Advertise Here


All times are GMT -7. The time now is 04:23.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2022, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.