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Author Topic: 12v wiring help please  (Read 1700 times)

tobyker

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12v wiring help please
« on: July 15, 2011, 05:02:02 PM »

In my narrow boat I've got a 12v 2.2Ah SLA battery, with a 4A fuse in the +ve line, then via a switch to a +ve and -ve busbar. To the busbars are connected 1. a 5A ESC (for the 380 motor);2. a 5v BEC; and  3. the microswitches for a car screen washer pump for the bow thruster.

My question is whether this is safe for the above components, or whether the starting amp draw of the thruster pump will pull current backwards out of the ESC and lunch it?
Grateful for advice from someone more familiar with the ways of the wriggly amps. I do have an ammeter, so i could test the washer pump amp draw if necessary.

PS must be raining - damp affectionate cat on keybord yecch!
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Tug-Kenny

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Re: 12v wiring help please
« Reply #1 on: July 15, 2011, 05:26:00 PM »


I would go for a separate fuse for each circuit. That way, any surge from your equipment will not affect the others.

Hope this helps

ken

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john s 2

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Re: 12v wiring help please
« Reply #2 on: July 15, 2011, 06:41:03 PM »

I agree with Kenny. Use as suggested sub fuses and increase main fuse. Better safe than sorry. Hope cat
dried out ok. Mine tends to like to walk over whats on my lap leaving paw prints Of the muddy sort. John.
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john44

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Re: 12v wiring help please
« Reply #3 on: July 15, 2011, 09:42:54 PM »

In my narrow boat I've got a 12v 2.2Ah SLA battery, with a 4A fuse in the +ve line, then via a switch to a +ve and -ve busbar. To the busbars are connected 1. a 5A ESC (for the 380 motor);2. a 5v BEC; and  3. the microswitches for a car screen washer pump for the bow thruster.
RE micro switches to directly switch on a car type water pump? You will be better of using the micro switch to switch a power relay coil
or a Action heavy duty switcher, wiring the power to the pump from the relay/switcher terminals.

PS Action have wiring diagrams on their web-site I am sure there will be something on there to help you.

john
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nick_75au

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Re: 12v wiring help please
« Reply #4 on: July 16, 2011, 04:17:00 AM »

You are not going to pull current backwards through the ESC, the wiring method you describe is similar for big boats with 500 amp thrusters and other electronics off a buss bar the difference being no fuse only switch between buss and battery, then individual circuit protection for each load.
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More Coffee

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Re: 12v wiring help please
« Reply #5 on: July 17, 2011, 02:08:05 PM »

Your concern is actually lunching the battery not the ESC .

What "may" happen is less current available for the ESC when the bow thruster fires up..  Like any battery it has its limits as to how much current it well supply..If your SLA starts to get warm from use ..your probably demanding too much from it..Though ..I highly doubt it with your configuration.Its a very light load from what I have read.

The only way I can see pulling current back through the ESC ..is if a guy were to use the drive motor as a generator to put current/voltage to the ESC power output leads and ran the bow thruster of the power input side of the ESC...If it's even possible %%

 
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tobyker

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Re: 12v wiring help please
« Reply #6 on: July 17, 2011, 10:59:33 PM »

Thanks folks. I will take a separate feed direct off the SLA through a fuse to the thruster pump. It's only going to be running in short bursts (I hope) and only has to push the water 3" instead of several feet to the rear window, so it shouldn't be too bad. I was just slightly worried about the amp draw at start. We shall see, but at least with the separate fuse I shouldn't do too much damage if things do go wrong.
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Re: 12v wiring help please
« Reply #7 on: July 17, 2011, 11:08:55 PM »

You'll be fine. :-))
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