new member wiring my boat

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julian.pitts
new member wiring my boat

hi guys

im a new member 2 days and have bought a 26x boat recently and its on its trailer at home, im looking forward to meeting members and sailing my boat

the previous owner didnt explain that the electrics didnt work and are poor, does anyone have a good set up they would recommend as i want to start from scratch, are 2 batteries best 1 for engine and 1 for the boat stuff

when in shore i want to plug into mains to keep batteries topped up, there is an inverter on the boat a water heater etc

there is a solar panel flexible are they any good??

any help would be brilliant

someone has even cut leads off the mast and pulled the plug rom the deck out so there is tape over the hole, not pretty, anyone recomment best 2 pin to that job please as well??

rick.jones
rick.jones's picture
Hi Julian, and welcome!

Hi Julian, and welcome!

The X when manufactured had very simple electrics, just the internal battery supplying navigation and cabin lights. Not even specific provision for an engine starter battery, so every X will have had some degree of custom wiring done on it.

Batteries - yes, a separate engine-starter and house battery is best. The starter battery is usually best located inside the bottom of the cockpit console. It should be wired directly to the engine using the heavy leads provided by the engine. Some people include an isolator switch, but in fact engine manufacturers don't recommend this, as outboard alternators and electronics are not designed to be run with no load, and can be damaged if the battery is disconnected while running.

In my experience the best arrangement for charging is to use a VSR (voltage sensitive relay) cross-charging system. These are small, inexpensive, and widely available. A quick Google led me to this example: 12voltplanet.co.uk/voltage-sensitive-relay-12v-140a.html. The page has a good description of how it works. One of the best things about these is they are completely automatic, just install and forget, much better than having a manual selector switch as is sometimes seen. Being bi-directional, surplus charging current from the engine will charge the house battery, and when the engine is not running, surplus current from the other chargers (connected to the house battery) will charge the engine battery.

Solar panels vary enormously in output, largely depending on the surface area. Small ones produce only enough for a trickle charge and can be connected directly to the battery. They will stop the batteries losing charge when the boat is not being used, but won't replace any substantial usage quickly. Those with a higher output will have a separate charge controller between the panel and battery to prevent over-charging. Exactly how much charge current you get can only really be determined using an ammeter.

Wind turbines can produce higher outputs (and also work at night!), but decent ones are very expensive.

For shore power, Mastervolt do a good range of sealed mains chargers, I have one of the small ones permanently installed. Does the water heater run from 12V or mains? If 12V it will probably take a lot out of the battery, as will an inverter if you plug anything hefty into it. You always need to consider if your charging system is providing enough current to replace what is being used. You also need to be sure your shore mains connection is fully isolated from the 12V electrics. Chargers like the Mastervolt are, but it's important that mains earth is not connected to 12V negative, otherwise you will need a galvanic isolator. Without one your outboard will steadily dissolve when plugged in - eek!

It's really odd that the deck plug for the mast connection has been removed, it's there to feed the mast steaming light (to be illuminated when motoring at night). This is the type of connector to get as a replacement: tcschandlery.co.uk/chrome-3-amp-2-pin-deck-plug-socket. If you're thinking of wiring more things in the mast you could get a 3 or 4 pin version, they're the same size. Connect the fat pin to common negative, and the thin pins to the different lights. Possibilities are a white anchor light at the top of the mast, and/or a deck light to see where you're walking at night. You can even replace the steaming light with one that incorporates a downward pointing deck light in the same fitting.

You can get access to the connections by taking out the white inspection plugs in the cabin ceiling, as well as the switch panel.

Make sure to get good quality cable when replacing or adding any wiring. In particular it should be tinned (not plain) copper. Un-tinned copper is very prone to corrosion in a salt atmosphere.

Good luck, let us know how you get on, and if you have any more questions (I'm sure you will!).

Rick Jones (Treasurer) 1994 Mac 19 "White Lightning", Isle of Wight

david.phillips
Hi and welcome to the club.

Hi and welcome to the club. The Mac 26 x is a great boat. I have owned several to buy and sell, but retain my original Mac . The problem is - a lot of owners modify boats to their own tastes which can be a problem when selling on ,just like a house. I have ever only had a single battery as my boat is marina based and have shore power. My batteries are topped up using mains power and an ordinary battery charger. Don't know why mast wires cut ? I would be happy to answer any more questions.

david.phillips
Hi guys. Being housebound and

Hi guys. Being housebound and not sailing this year, I have found some relief watching sailing videos. One tha I am hooked on is PROJECT ATTICUS. an American couple restored a 50 year glass fibre old 30 ft boat and are sailing the Caribbean. They are very enjoyable to watch and you can learn a lot about sailing. Share her project atticus on you tube, I'm sure you will enjoy it. Regards to all Mac club sailors.

julian.pitts
hi 

hi

also the bung for the air intake for the ballast where could i purchase one of those please

rick.jones
rick.jones's picture
That plug is technically a 1"

That plug is technically a 1" snap-lock drain plug, primarily used for dingy transoms. Widely available, I found one on Amazon at a reasonable price here.

Rick Jones (Treasurer) 1994 Mac 19 "White Lightning", Isle of Wight

julian.pitts
thank you 

thank you