Critical equipment - wired through the main switch or seperate fuse

Wunja

Wunja

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I read somewhere that critical equipment such as bilge pumps and the VHF radio, should not be wired via the main switch panel, but take a direct, fused supply from the battery.

Please can any one offer supporting or contradictory arguments to this?
 
My bilge pump is on a float switch and wired straight to the battery so it will pump out any water that comes in while I'm away from the boat (battery selector would be turned off).

VHF comes via the switch panel. The only reason I can think of for having it straight from the battery is so that if its needed in an emergency, such as a mayday, and you sail with novice crew who don't know the boat, then all they have to do is turn on the VHF at the set.

I normally sail with VHF turned on, but at night, at anchor I turn it off at the set and probably sometimes at the switch panel too.
 
I would suggest automatic bilge pump, plus memory for radio/CD player and intruder alarm (if fitted), direct from battery (via suitable fuses).
All other equipment via main battery switch.
 
Your choice. You can get "always on" units which you can use to connect such things as automatic bilge pumps, stereo radios which need a supply to keep their memories and VHF if you wish. This cuts down the number of wires that go back to the battery. On my boat I also have an emergency battery, charged from the house battery that feeds the VHF and GPS, but this is to comply with Greek regulations, and would not be my choice - overcomplicated and the battery is in the same location as the others.
 
Re: Critical equipment - wired through the main switch or separate fus

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My bilge pump is on a float switch and wired straight to the battery so it will pump out any water that comes in while I'm away from the boat (battery selector would be turned off).

VHF comes via the switch panel. The only reason I can think of for having it straight from the battery is so that if its needed in an emergency, such as a mayday, and you sail with novice crew who don't know the boat, then all they have to do is turn on the VHF at the set.

I normally sail with VHF turned on, but at night, at anchor I turn it off at the set and probably sometimes at the switch panel too.

[/ QUOTE ]

Same with mine, bilge pumps to batteries via fuse and on/off/auto switches. VHF via panel, on board the VHF and Navtex is on the same switch which I have also marked 24hr. I am about to set to building a new panel and might put the VHF under one of those lift cover switches to prevent accidental switching off.
 
We always dual feed critical equipment.

Bilge pump, float switch direct from battery via fuse, no switch. The bilge pump also has a feed via a seperate circuit breaker and switch from battery isloator switch, this provides a alt pump feed and manual operation. No off switch is fitted as it will be off as the boat sinks.

VHF and nav equip supplied from both service and engine battery, this is via a combiner that draws the power from the higher voltage battery. This is supplied via circuit breakers, power taken from battery or isolator switches, owner choice.

If rearly worried you can fit a high level reserve battery, this is normally in circuit with the service bank, should battery voltage drop, this battery bank is isolated. Critical equipment is then supplied from this dedicated bank, while the remaining service power comes from the remaining service bank.

All depends on how worried you are about critical power supply.

Brian
 
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No off switch is fitted as it will be off as the boat sinks

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Bit of a bugger if you are washing the bilges or moving the float switch if you can't switch it off...
 
Its up to you but the best set up for critical equipment is to have it fed seperately, directly so that it can't be interupted. An example of when this might be important could be in a collission, with damage behind fuse board, a fire and lots of wiring is melted. Many fires are electrical and will be a component on the main loom.
I know you aren't coding but this is good advice.
MCA directions are
16.1.5 When the electrical supply to radio equipment is from a battery, charging facilities, or a duplicate battery of capacity sufficient for the voyage, should be provided. Battery electrical supply to radio equipment should be arranged such that radio communications should not be interrupted.
 
The phrasing is a bit vague. By 'should not be interrupted' does it really mean that the VHF power shouldn't go via a switch?

Sounds more like a scenario such as the VHF not working while the engine is started, for example. I would consider that an interruption.

Admitadly though, it's possible to imagine someone reaching to turn on the bilge pump, or some other switch, and accidently pressing the radio switch, while the radio is being used to send/receive emergency traffic.

When the boats slopping around and the floors wet, it can be like trying to send a text message with your thumb.
 
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The phrasing is a bit vague. By 'should not be interrupted' does it really mean that the VHF power shouldn't go via a switch?

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Not interrupted is not interrupted, you should be able to draw power from either battery without loosing power during switching over.

Why fit a switch? vhf normally has one, another only adds another failure point.

Brian
 
Tranona
I wasnt aware of the emergency battery regulation ?
Is this a requirement for greek flagged boats. I assume it doesnt apply to visitors ie UK flagged boats?
 
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