Switch panel wiring

Hi all,

I have a switch panel to put into a boat and want some advice about the most efficient and "standard" way to wire a boat panel in.

It is the sort of panel you find in most sort of "modern" yachts, it has on/off switches for everything like nav, vhf, cabin lights, nav lights, bilge, aux, fridge etc.

The switchs on the back have 3 tabs, not labelled. When I buzzed them the two end tabs seem to be connected as a standard switch but the middle tab seems not to be connected regardless of the switch postion. This seems odd to me.

Each switch has its own fuse prior to it, I was hoping to put a +V feed into one fuse, diasy chain on to the following fuses to reduce wire usage. Then take an output from each fuse onto the switch and then from the switch to the device and the a common from the device back to the switch and onto a busbar.

I want each device to be fused and switched separately, I don't mind if it is switched before or after the device.

The three tabs on the switch is what is confusing me. Can I use one as +V one as common and the middle one to take a +V feed to a light for example. I would have thought this would have buzzed though in the on position?

Or is this what I buzzed? The two +V tabs buzz with each other but the common tab is completely separate from them? As I write I am thinking this must be the case? Standby, I may be having a Eureka moment....

Anyway, any help on the above is appreciated.

 

Wlcome to the forum.

You need to be a bit more specific, as there are several different types of switches.



A typical single pole, single throw switch. Open in one position, closed in the other.



This is a typical double throw, single pole. The center position is open, with the up or down positions being closed. This switch shares a common feed.



This is a double pole, double throw, 3 position switch. Center is still off and up and down have isolated (separate) feeds. You can get a 2 position switch, much like this, but there's no center off position, just one or the other.

There are lots of switches and ways to wire them. The same is true with each circuit you'll be employing. For example if you wire your feeds to each switch as you've described, it'll work, but if the one fuse takes a dump, you'll loose everything else down stream of it. It would be better to fuse the devices separately and not the feed wire. Now, this could be done in series as you've suggested, without everything taking a dump if one fuse pops.

Pick up the "12 Volt Bible", it'll pay for itself as soon as you've finished this job.

 

Try Nigel Calders Boatowners Mechanical and Electrical Manual, every boat should have one.

I somehow reckon the other wire is for the negative to make the internal light work from the description.

 

You're probably right Landlubber.

If these are decent switches they must have markings like a brand name, UL or CE and the contact function in numbers or C/NO/NC etc.

 

It wouldn't be logical to have both sides of a 12 VDC circuit on a switch. A three conductor, 3 position switch is shown above and can be wired a few different ways, but without specifics or maybe an image of the switch's labeling, just some guess work.

 

Post removed by user. Reason: unwaranted post.

 

This link has a lot of useful information:
http://www.uscgboating.org/regulations/boatbuilder_s_handbook/electrical_part3r.aspx