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  Topic Review (Newest First)
08-16-2006 05:05 PM

Ok...I confess I can't remember. But since I make the rules on my boat (my wife lets me ) the CO monitors ARE law. Didn't mean to misquote although it seems reasonable that a USCG safety check should require them if you have a permanently mounted engine aboard.
08-16-2006 02:19 PM
hellosailor "I think you're required by USCG (????) to have CO monitors " Perhaps on commercial vessels, not on recreational ones. There are still a number of laissez-faire Darwinists at the USCG, more power to them!
08-16-2006 10:28 AM
CO monitors for generators


Thanks for the reminder about CO monitors. I think you're required by USCG (????) to have CO monitors anyway regardless of the presence of a generator. I'm not 100% sure that's correct but I'm living like it is. Then again, that's the beauty of running a small A/C unit off batteries. We don't do it very often, but if it's really hot at anchor, I can cool the boat down with both A/C's going and the generator on while sitting in the cockpit. Turn off the generator (put it into automatic mode), and then run the aft cabin A/C in humidity mode for the night off the batteries. That sucks out about 200 amp/hrs from the batteries overnight, leaving me with about 700amp/hrs or 30% discharged (880 ah to start). Humidity mode keeps things comfortable in an already cooled-down cabin and doesn't pull the batteries down enough to make the generator kick on. Works great for the occasional use. I'm with you on the CO--I wouldn't run a genset at night while sleeping--life's too short. BTW--the Panda 4000AGT has an extra external control +/- which will kill or start depending on how it's setup so you can kill the generator if the CO alarm goes off. That's in addition to the battery monitor to turn on when the battery bank voltage drops to a selectable level.
08-16-2006 08:08 AM
sailingdog If you're going to be running a genset or is imperative to have a CO alarm that is able to kill the genset if the CO levels increase.
08-16-2006 03:11 AM
12 volt generator is also an option

Depending on your house bank size, you also might consider a 12v generator. I have a similiar sized boat (40 ft with a 16K and 7K A/C units plus microwave and 900 ah house bank) and did a fair amount of thinking before deciding on my generator. I ultimately went with a Panda 4000 AGT (4kW but DC at 14 volts). My rationale was as follows:
1) sleeping at anchor with A/C if truly necessary only requires the 7K btu unit which is in the aft cabin and runs on 7amps @ 120v
2) I can run the aft A/C unit off the house bank for the startup to get past the surge requirement--comes out of the battery bank--and then the generator kicks on when the house bank voltage drops as below in #3
3) the Panda 4000 AGT generator can be configured to turn itself on when the house bank voltage drops below a preset level
4) "Loading" the generator appropriately isn't an issue because it runs at a variable RPM to match the load--no need to worry about a fixed RPM of 1800 or 3600 to match the 60Hz cycle of 120v output. Since the generator runs to charge the battery bank and not to match some load, the generator is always appropriately loaded (and more fuel-efficient than a 120v generator supposedly).
5) battery charging is quite rapid for the bulk phase as the generator puts out 280-320 amps DC at 14 volts (of course configurable for battery type).

I don't mean to sound like a salesman (I'm not) but I really really like this generator setup. Of course, this whole shebang is predicated on a large battery bank that can accept a large charge current (I have Lifeline AGMs) and a large inverter that can run the A/C (I have a Freedom 25 and a dedicated 3000watt/5000watt surge inverter for the A/C units when not on shore power).

Just another option to think about depending on your needs.

Have fun,
08-15-2006 02:19 PM
kavakava Thanks for all the input. On the Hunter 41, there's a ton of room in the lazerette, and the fuel tank and elec panel are already set up for gensets. There are CO monitors on the boat, but the previous owner disconnected them because of frequent false (?) alarms. I need to revisit this issue. Our basic elec needs are 50 amp battery charger, hot water occasionally, microwave, and 2 A/C's, 12 & 16,000 btu's. We don't have an inverter at this time, but might look into it so we can run the microwave without starting the genset. While we're in FL visiting the outlaws, we're going to swing by Jacksonville and look at the Nextgen 5.5. They build them there and they turn 2200 rpm.
08-10-2006 12:18 PM
Cruisingdad Check the startup versus run amp/KW. Most good generators can take a much higher startup than run. I think the Fischer Pandas and Mastervolts are the quietest on the market. Also look into the wet exhaust system. Makes running it in a crowded anchorage more bearable for you and your neighbors.

By the way, have you priced these yet? Are you going to do it yourself? Better budget $10,000-$15,000 dollars (with 10k being WAYYYY conservative). You will likely have to glass in a shelf, run the fuel lines (including return), electrical, etc. Major project that you CAN do by yourself, but the money may be better spent letting a yard do it for you (reputable yard, that is). Also, I STRONGLY suggest adding CO monitors downstairs in all the cabins and salon. If CO escapes inside a lazarette, it will rest in the bilge and slowly make its way into the living quarters. You cannot smell it. Chances are that if you did realize you were poisoned, it could be too late. We almost lost some good friends of ours that way.

I would have a CO monitor on my boat before a life jacket... and I cannot imagine anyone dumb enough not to go without a life jacket.

Just thoughts. You can PM me if you have specific questions.
08-09-2006 10:37 PM
camaraderie Good advice above from cruisingdad. You really need to figure out the AC amp load you might have in use at onne time. Wattage equals AMPS times Volts. So the KW generator you need is one that can supply MORE than 115 x whaterever your typical max AMP load is. A 30 AMP load = 3,450 watts or 3.45KW or about a 4KW generator. A 50 AMP load...generates 5.75 KW & needs a unit of about 7.5KW.
Can you live on the hook without both A/C's on? Can your battery charging be done while the A/C is off? What does adding the water heater into the mix do? Can you live without it? If can save on size, weight and noise. Just check out your Ammeter while plugged in dockside under various scenarios and you can quickly figure what you need...but don't skimp or cut it too close as start-up loads can often be twice as high as running loads!
08-09-2006 06:38 PM
SledDog You may also want to look at the Entec 35 amp AC genset. With its sound enclosure it is about 2ft wide, 1.5 high and about 1.25 deep. It is quieter than our AC (Marine Air). We manage the load at 25-28amps max but generally run less than 6. We recharge 675ah battery bank via Xantrex, run AC and seldom see more than 13amps AC. Waterheater is the big load that we watch out for. We have been very pleased with Entec responsiveness on spares supply issues and the manual is the best I have ever seen on any piece of equipment I have ever had on a boat.
08-09-2006 02:28 PM
Mastervolt and Fischer Panda

My first boat had a Fischer Panda and my newest has a Mastervolt.

I never had any problems with my FP, but I have heard many people talking about warranty issues with them lately. They are quiet and dependable. Mine was a 4.5, and it ran two a/c systems (a 12k and 16k) marginally well, but preferred to just run one or the other with the charger or other ac systems. On a hot day, it was tough to run the microwave and the ac without a shutdown. You do have to keep a pretty good eye on the panel and load to keep from overheating it.

My newest boat has a 3.5 Whisper Mastervolt. I got it with some reservation, but love it now. I would reccommend it without reservation. it shows you the load, run time, has auto start function for batteries, etc. Its control panel is pretty dummy proof. You will especially like the way it shows the %load, so you do not over heat. I can run both a/c's (12k & 16k) for about two hours before it really starts getting warm, or can run one a/c and everything else indefinitely.

I would probably lean toward the Mastervolt if I was going to reccomend one of the two. It seems about as powerful as the 4.5 FP, and has soooo many more functions that make it very nice.

My very strong reccomendation when sizing a generator is not to exceed 80% load. The trick is also not to oversize it. ANything over 80% load will likely overheat your genny or reduce its lifespan. However, oversizing it and not having it under a good load can be as bad or worse.

I know at first it might seem to make more sense to have a generator that can run every single ac item on your boat at the same time, but chances are that if you size it that big, you will be underloading it 90% of the time. One a/c unit in the evening should get your boat down pretty cool... and you can flip back and forth between them to pull the temperature down. The charger can be a big draw if your batteries are low, so keep that in mind too.

Let me know if you have any questions. Hope that helps.
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