Electrical Redo on Mac 26x

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T

TexasEd

Has anyone rewired a Mac 26x? My electrical looks like a rat's nest and the running lights are intermittent. A circuit diagram would be helpful. I know this is a common problem with Macs, so I hope someone can lend me a hand. Thanks.
 
Jun 5, 2004
997
Macgregor 26D Boise
This is a common problem with many boats, not just Macs. The pressures of the sales market means that most manufacturers provide the cheapest e,lectrical system to do the job, and from day one it is going downhill. I have totally rewired a couple of boats now, I find it is better to start with a clean slate, beginning with removal of all substandard wire. Choose a resettable circuit breaker panel with enough circuits for all needs, present and future. You need a battery switch of suitable capacity. You can change the location of these components to keep primary DC runs between battery and panel short. If your boat is constructed like my D model, it is possible to fish the wires between the liner and the hull for a clean look. I rewired a D using 180 ft of 2 conductor- only a couple of inches were visible. Take your time and make it a work of art.
 
T

Tontos Revenge

wire?

O123--what type of wire did you use? I'm about to start wiring my V25 for shore power and have heard different theories about the type of wire I should use...everything from lamp cord to 12-3 Romex.
 
Jun 5, 2004
997
Macgregor 26D Boise
Check out the marine wire vendors on Ebay. Use the correct wire, it is not that expensive. Do your self and your loved ones a favor, and buy a wiring guide before you bring AC power aboard. An author named Nigel Calder is a good source. His books cover a lot of ground, but the sections on boat wiring will keep you USCGaurd compliant. The spartan KISS design of minimizing all systems of their boat design works fine for Macgregor, but you definitely need to educate yourself if you are considering AC. I only say this to you because I care about you....John S
 
Jun 5, 2004
997
Macgregor 26D Boise
O123--what type of wire did you use? I'm about to start wiring my V25 for shore power and have heard different theories about the type of wire I should use...everything from lamp cord to 12-3 Romex.
Definitely see this month's Sail magazine, there is a tech article about AC wiring....
 
Jun 3, 2004
309
Prindle 18, beach catamaran Chicago (North Edgebrook), IL
All this scary AC talk got me wondering, why couldn't you install a shore power plug, connect that directly to a battery tender, connected to the battery?
The battery would also be connected normally to the circuit box, connected to the lights, radio, cigarette lighter, etc.
It would make it easier to charge the battery, and you could plug small appliances into the lighter outlet. Perhaps even use an inverter.
Is this a terrible idea, or awesome cool?
 

walt

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Jun 1, 2007
3,541
Macgregor 26S Hobie TI Ridgway Colorado
My boat has very simple AC... I have a three prong AC inlet which goes to a three prong power strip inside the boat - ie, essentially no AC boat wiring. I plug an AC three prong battery tender in the power strip (using its supplied AC power cord) and also a space heater which I believe is also three prong - also using its supplied AC power cord.

My battery tender isolates the AC earth ground from the DC boat ground - which is a good thing from a corrosion standpoint and easy to test with an ohm meter. My outboard has a alternator and when the outboard charging system is hooked up, the outboard chassis is conected to the boat DC ground. If my battery tender did not isolate the AC input ground from the battery DC ground and I left the boat at a marina with "stray ground currents", I could have accelerated corrosion on the outboard if it were left in the water. Problem also solved by simply keeping the outboard out of the water since the Macs have no other DC grounded metal which is in contact with the water.

If you need to start wiring AC inside the boat, the referenced article sums it up well (ie, GFCI sockets and galvanic isolators, etc)
 
Jun 5, 2004
997
Macgregor 26D Boise
I think that the USCG Regulations were formulated with the worst case scenario in mind. You can certainly run an extension cord into your boat, if the marina will let you. You might find that the ease of connection to shore power with a proper set up is worth the expense/work. Remember that another person with no electrical sense may be on your boat. The USCG regs protect that person or child....
 
Jun 5, 2004
997
Macgregor 26D Boise
Dancing Bear
You are certainly correct about the system you describe, I have installed a system just like that on a 26D. After you have installed those described items, it would only cost a few bucks more to be USCG approved. I have found GFIC outlets on sale at Home Depot for less than 5 bucks. The most expensive item, besides your charger, would be an AC circuit breaker. These do come up on Ebay and they basically "break" both legs of the AC circuit, rather than a single leg on a DC CB panel. The new chargers for bass boats incorporate a lot of the desireable features you want: ability to supply constant DC up to a rating, ability to apply multi-step charging to you batterys to ensure maximum life (think MinnKota). The reasoning behind the rules is at least partially that a person standing on a wet boat with bare feet can hook up the AC and know they won't be shocked and all polarities are correct. Inside the boat, anyone can make the most bonehead error with the AC power and still survive (think Margaritaville).
 
May 4, 2005
4,062
Macgregor 26d Ft Lauderdale, Fl
Hi John,

whats your opinion please:

I have a 10ga 50' extension cord w/ a 30 amp male plug (twist dock plug), and a 3 prog female plug, then a GFI plug, then a 5 outlet power strip.

into the power strip I run a 5000 btu a/c and some light, plus a batt charger.

All of this is just wires laying on the boat and cabin.

am I at risk here? do I need a circuit breaker, marine input and gfi outlets intalled and mounted?

-I rarely use this setup, but sure don't want to be dangerous when I do.

TIA!
 
O

oreana1234

Hi Mr Bill

There is a big difference between the kind of things we do, and the kind of electrical wiring someone is PAYING me to do. My professional opinion is that you have a dangerous situation, from a lack of a main breaker to unsecured wires. I wonder what the total amperage draw is in your system, with all items drawing?
 

walt

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Jun 1, 2007
3,541
Macgregor 26S Hobie TI Ridgway Colorado
I have a 15 amp AC receptical on boat in the cockpit area so that I dont need to run the extension cord through the companionway hatch (mostly so I can close things up for the heater). Inside the boat is wired the end of an about 1 foot extension cord with a multi socket breakout. Definately a hack job but "unsafe" is relitive. I think its safe - but not completely moron proof.

If you look at AC wiring systems, there are three wires - hot, nuetral and earth ground. The hot and nuetral carry all the current and if you somehow short the hot and nuetral, it should trip a breaker somewhere. In my case, the breaker is either in the marina or in my house. So too large of a load or somehow shorting the hot and nuetral together will blow the breaker - but its takes a big current load - like 15 amps (or whatever the breaker is).

Normally, all the current is on the hot and nuetral lines and there should be no current on the earth ground. The GFI simply makes sure that all the current flowing on the hot returns on the nuetral. If there is a small mismatch (and it really is small - like 25 ma), the GFI trips. Ie, if some small portion of the hot current somehow gets on the earth nuetral, the GFI will trip.

So what condition does the GFI protect for? The one important case I can think of is the hair dryer falling into the bath tub. In this case, the water would conduct sufficent current between the hot and the earth ground to trip the GFI breaker. Likely over time, the GFI has saved some lives for this type of accident. I dont think anyone has done a mod to add a hot tub to the inside of one of these trailerable boats (yet:eek:) but there could be some risk of a power cord falling over the side of the boat and posing some risk to someone in the water??? GFI would also trip if there was a short between the hot and the earth ground but in general, so would the main breaker fuse.

If I had some liability for an instal however, I would dang sure put all the safety stuff in. Heck.. I lived in a house which had no earth ground wiring at all (built in the 60's) and somehow survived. Just dont leave the hair dryer near the bathtub.
 
Jun 5, 2004
997
Macgregor 26D Boise
Yeah the hair fryer would do it. But what about appliances from certain countries that are made without any possibility of liability by those who have no idea what they are doing? The really dangerous item would be wired incorrectly, one of the hot legs wired to the body or chassis, and the appliance or whatever works normally. You would want a GFI to stop this current. Another characteristic of a GFI is the reaction time, in millisecs, for it to do its job.
A great book I was reading postulated that at least some of the drowning deaths that occur annually in marinas are partially due to stray current leakage. I don't ever swim in marinas.
 
May 4, 2005
4,062
Macgregor 26d Ft Lauderdale, Fl
Thanks for your opinion, John I apreciate it.

-just to clarify, the lack of main breaker is dangerous? the GFI and the dock breaker are insufficent?


-yeah, I understand about the loose wire, and do try to secure it well, the few times I have used it.
 

walt

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Jun 1, 2007
3,541
Macgregor 26S Hobie TI Ridgway Colorado
A guy I talked to recently was telling me about lawsuits with outdoor gardening products for a company he had worked for in the past. Someone was using a electric grass trimmer with a very frayed power cord wire or something like that - barefoot and standing in water using the trimmer. The guy got electrocuted (ie, died). A GFI on the socket where the extension cord was plugged in would likely have prevented the death (as well as just a tiny bit of common sense) as long as the grass trimmer used a three prong plug. The outlet was fused but this of course makes no difference since the fuse wont blow.

edit - probably not correct above that the GFI required the extension cord to be three wire to work. In this case, the GFI would likely have still prevented death even if a two wire extension cord was used as the current from the hot wire to actual earth would have created the imbalance in current between nuetral and hot and triped the GFI regardless if there was an earth ground wire in the power cord.
 
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