dc wiring

[northerncat]

i am in the process of wiring my boat up and i have a question is it better to run all your wiring to the switchpanel or to have a few sub panels around the place to save a little wiring
sean

[cat man do]

On my last cat I treated it like 2 mono's and had batteries and panels for each side, and will more than likely do the same again.

Unless given a very good reason not to of course.

Dave

[Pblais]

I think it comes down to the amount of wire. Large Gauge tinned copper wire isn't cheap. With DC wiring the length of the run and the amps drawn determine the gage of wire needed. The perfect system would have short wires and the fewest junctions. Two systems could be the better choice with a cat. A few items duplicated but a lot of wire eliminated.

Using sub panels I don't see as a way to make it any easier or cheaper. The length is still the length with DC. You need to forget about AC current building wires and panels as they don't have the voltage loss problem of DC current so all those techniques that work ashore don't apply here.

[Lynx]

I am having another panel put in because the orginal one did not have enough breakers, However it is very close to other. Another panel, far away, in a small boat does not see worthwhile. Just more stuff to go wrong.

Panels close are - Easier to fix if broken. Faster to trouble shoot.

[PBzeer]

If you are doing a complete rewire, you might want to look into the new wiring system Nigel Calder is putting on his new boat (he sold his just finished boat, to get one with this system).

As I understand it, you run one cable down the boat, and tap into as needed. It's a bit more complicated than that, but it's been a while since I read about it, to try to be more specific.

[cat man do]

Originally Posted by PBzeer

If you are doing a complete rewire, you might want to look into the new wiring system Nigel Calder is putting on his new boat (he sold his just finished boat, to get one with this system).

As I understand it, you run one cable down the boat, and tap into as needed. It's a bit more complicated than that, but it's been a while since I read about it, to try to be more specific.

Could this be what you are talking about mate?

EmpirBus - Products

Don't know much about it myself as I'd reckon it's out of my league $$$ wise.

The SuperYacht Group in Cairn's look after it, need I say more ?

Dave

[northerncat]

in my situation i have 7 wires coming out of the roof for lights if i run them to the main switch board i use an extra 21 metres of wire, i was thinking that in this area i could have one larger wire from the main switchboard running to a bus off which i have all my roof lighting connected? so i have 3m of heavier wire plus 1 bus bar and only 1 switch from the main panel? does this sound clever and simple or is it false economy?
sean

[Chuck Baier]

Sean, your idea will certainly work so long as all wire used is sized to carry the loads and the circuit breaker is appropriate for the entire load. You will not be able to shut down only part of the circuit if a problem occurs. You say you have seven wires. Does that mean they connect to seven lights or are there more on the circuit. This too needs to be considered.

[Lynx]

If you loose the panel or the main feed you loose your lights.

If you wire every light seperatly and you loose one, you have only lost one.

Your cost is about the same.

You can also run spair wires for future needs. Fans?? 12v outlets??

[northerncat]

only seven lights in the roof, i was thinking of treating each hull and the steering console with its load of nav gear seperately with a different smaller switch board and bus bars thereby decentralizing the power within the boat and using a few heavy wires to feed power to these different areas
sean

[Chuck Baier]

Be careful getting carried away with the bus bars. Many items need their own circuit breakers. Some items like nav instruments can be on a single circuit breaker but will need in-line fuses for individual units. There is nothing wrong with spreading the circuits out through out the boat with seperate panels. Just be sure each panel has a disconnect for the entire panel for safety.

[Boracay]

My local chandler sells 4mm tinned wire for .71 per metre in 50m rolls.
Is this the wrong wire to use for lights and small devices (current draw less than 2 amps)?

[NoTies]

If your chandler sells 4mm tinned wire for 71c/metre buy a whole lot & send me some. I paid (cheapest price I could find for good quality) $3/metre for 2mm over here. Big is good so won't be a problem unless it doesn't fit into terminal posts etc. then you would have to solder on a smaller pigtail. If I could buy tinned wire for that price I would rewire the whole boat in it.

[Boracay]

I buy from Whitworth's: Electric Cable 4mm Single Black
They say they ship overseas so it may be worth contacting them and asking.
I think the measurement refers to the area while you may be thinking of the diameter.
In general I have found their prices to be very competitive with other chandlers, hardware and specialist stores.

[northerncat]

yes my 1.87mm crosssection costs me 2$ a metre
sean