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Old 08-16-2018, 03:00 PM   #61
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I spoke with Trojan battery tech and they say the short circuit rating for T-105 golf cart batteries is 2000 amps so if you have the Blue Seas battery terminal fuses, you are OK.

They have a 10000A interupt rating at 14V.



Well that's good news.
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Old 08-16-2018, 06:33 PM   #62
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Yes and theres already a lot of hand wringing over it..... hopefully it will become more clear as all the tech heavy guys debate it for awhile.
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Old 11-03-2018, 07:20 AM   #63
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Is there a reason to have a separate On/Off switch for each engine?

I have 3 diesel engines, 2 mains and a generator. The generator is 12v to run, and the two mains are 12v to start and shutdown but once started run fine without power. The current DC wiring does not reflect the good practices discussed in this thread, and I intend to correct that this winter, but there is a mechanical On/Off switch in the engine room for each engine between the battery bank and the starter. I'm wondering if there's a good reason to preserve the On/Off switches or if there's a general design practice I've missed that indicates the switches are a good idea.

Thanks for your help and insights.
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Old 11-03-2018, 09:44 AM   #64
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... but there is a mechanical On/Off switch in the engine room for each engine between the battery bank and the starter. I'm wondering if there's a good reason to preserve the On/Off switches or if there's a general design practice I've missed that indicates the switches are...
Starter solenoids have been known to stick ON. If that happens without an upstream switch, then describe what to do next.

I've only seen it once, but that was enuf to convince me.
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Old 11-03-2018, 10:31 AM   #65
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Originally Posted by GregBrannon View Post
Is there a reason to have a separate On/Off switch for each engine?

I have 3 diesel engines, 2 mains and a generator. The generator is 12v to run, and the two mains are 12v to start and shutdown but once started run fine without power. The current DC wiring does not reflect the good practices discussed in this thread, and I intend to correct that this winter, but there is a mechanical On/Off switch in the engine room for each engine between the battery bank and the starter. I'm wondering if there's a good reason to preserve the On/Off switches or if there's a general design practice I've missed that indicates the switches are a good idea.

Thanks for your help and insights.
There are a few "small" exceptions which then must be fused, but having a shutoff switch between every battery and its load is absolutely the right thing to do.

Ken
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Old 11-03-2018, 11:01 AM   #66
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In response to post 63. Sure, the mechanical diesels will run w/o power. They won't shut down w/o power unless you can reach the fuel cutoff solenoid and manually operate it. The instruments and warning sounder won't operate w/o power. You cannot operate your engine/battery cutoff switch, or manually shut the engine down unless you're in the ER. You would have to deal with post 64's stuck solenoid scenario by flinging the furniture aside, opening the engine hatch and climbing down, or at least by getting there from the helm in some PDQ way.


I have finished my rewiring project by arranging battery/engine switches at the lower helm and fuses on the battery posts.
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Old 11-06-2018, 06:10 AM   #67
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"On/Off switch in the engine room for each engine between the battery bank and the starter. I'm wondering if there's a good reason to preserve the On/Off switches or if there's a general design practice I've missed that indicates the switches are a good idea."

KNOWING the engine electrics are disconnected is the safest way to service the engine.

The off- on switch should include a field disconnect , if you value the alternator.
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Old 11-06-2018, 11:05 AM   #68
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"The off- on switch should include a field disconnect , if you value the alternator."

...if your alternator charge cable is wired through the switch. If your charge cable runs directly from the alternator to the battery, this is not applicable.
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Old 11-06-2018, 08:42 PM   #69
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If by"charge cable " you mean the power to the alt. field ,, the diodes will depart if the charging alt is disconnected from the battery.


Perhaps a 1 wire auto unit will not blow the diodes, I have never tried.
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Old 11-06-2018, 10:53 PM   #70
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I have a large charging cable running directly from my alternators to their respective battery banks. These cables are not switched but they are properly fused.

Only my loads are switched at a point outside my ER door. If I turn both switches to off, it doesn't affect the charge circuits. It only cuts the load side of the system.

Both engines continue to run and both alternators continue to charge the battery banks.
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