Portable generator setup with aircon and inverter

[captstu]

I added a 200 Amp alternator to two engines.

Ran a 3kW inverter that powered a 16
Btu/hr ac and a washer dryer. One at a time.

For. The cost, look at a large alternator.

[mcon12000]

I’m not going to get into the portable generator debate. I have one and find it a useful backup to other systems.

You stated you’re new to this so let me say that at anchor you’ll find the boat is quite comfortable. It’s in the Marina that I run my air conditioning pretty much all the time during the summer months. Use your boat and spend your money on improving reliability, safety and other comfort items. You’ll have a completely different set of priorities after six months of cruising. When I started out I was thinking exactly like you are and placed a huge priority on the air conditioning only to realize it’s a non issue and Im glad I didn’t spend any money to address it.

[rreid01]

Chotu is correct. Even if your A/C will run within the power limits of the output your generator will provide, it won't be able to handle the locked rotor demands of the compressor start. The soft start uses capacitors to store energy, then provides it back during a peak load, like a compressor start. It's a neat trick.

I've got a small Cruiseair unit and a Yamaha 2200 generator. Without the soft start, it will trip the generator off when the compressor starts up.

However your second problem, at least with the small generators, is they don't have enough fuel to run all night.

I find 90 plus percent of the time I don't need the A/C on when we are at anchor since we generally have wind coming through the boat keeping things cool. For the few times we might need AC at anchor, the generator will run long enough to keep things cool until the temps drop naturally overnight.

[garyfrankovich]

This is just and FYI for everyone using or contemplating using a portable gasoline generator, and I know they are very popular because they are so much cheaper than an installed marine generator, I see them often on cruising boats. You should DEFINITELY clear it with your insurance carrier. These portable generators have no approved marine fuel system, no approved marine exhaust system, when you use one on your boat it has NO GROUND, and they ALL produce a HUGE amount of Carbon Monoxide. Most insurance companies will not cover them or allow them on the vessel. If you use it (at least on a US registered vessel), and someone dies from CO, or gets electrocuted because it is ungrounded, you better have at least $1,000,000 in some type of liability insurance.

[boatpoker]

Originally Posted by garyfrankovich

Most insurance companies will not cover them or allow them on the vessel. .

Done more than a few insurance surveys, deal with underwriters frequently and I've never heard that before.

[team karst]

The “no ground” comment is bogus as well.

[garyfrankovich]

So please inform me just how the portable generator is grounded?

[sailorboy1]

[QUOTE=rreid01;3604407.

However your second problem, at least with the small generators, is they don't have enough fuel to run all night.
[/QUOTE]

Easy to overcome with an extended run gas cap and a outboard engine type of gas tank

[boatpoker]

Originally Posted by garyfrankovich

So please inform me just how the portable generator is grounded?

ask yourself ... how is an inverter grounded when at anchor ?

[garyfrankovich]

If it is non-marine approved inverter (think Harbor Freight) it is NOT Grounded and also a danger and I recommend removal, if it is a marine inverter, it's grounded the same way an installed generator is, by both the chassis and the actual inverter, a portable generator is not grounded to anything.

[boatpoker]

Originally Posted by garyfrankovich

If it is non-marine approved inverter (think Harbor Freight) it is NOT Grounded and also a danger and I recommend removal, if it is a marine inverter, it's grounded the same way an installed generator is, by both the chassis and the actual inverter, a portable generator is not grounded to anything.

My 30amp shore power cord has a ground (as does everyone elses), When it's plugged into the genny it's grounded to the same system as an inverter. My Yamaha also has a chassis ground connection that is connected to my mast which is connected to boat ground.

[team karst]

Originally Posted by garyfrankovich

If it is non-marine approved inverter (think Harbor Freight) it is NOT Grounded and also a danger and I recommend removal, if it is a marine inverter, it's grounded the same way an installed generator is, by both the chassis and the actual inverter, a portable generator is not grounded to anything.

The word “ground and grounded” are problematic.

Plastic boats, and everything in them, do not present circuits that have a low Z to the earth.
But, short a lightning strike, that is not important. What is important, is that there is a non-current conductor, that is able to clear a fault safely.
That means, when the hot side of your 120V system, contacts a metallic surface, an overcurrent device responds. If u plug in your “dangerous” portable into your 3 pin shore power inlet, that non-current carrying conductor is intact throughout the boat. And a fault to metallic, bonded, object will clear.

[Ike]

Personally (and professionally) I am opposed to using portable generators on boats. The two major issues are Carbon Monoxide and shock hazards. But the carbon monoxide problem can be mitigated by leaving them out in the open air (be careful of which way the wind is blowing) and the ground problem can be mitigated by how you connect them to your on board AC system.
In the world of marine electrical systems the word ground and the word grounding have two different meanings. AC wiring uses a three wire system, the black wire is the hot wire, the white is the neutral (but also hot) and GROUND wire, and the green is the safety GROUNDING wire.
The white wire is always grounded at he source of power. On shore that is back at the power station. On a boat with a generator the source of power is the Generator (which is actually an alternator producing AC). The Green wire is always connected to the white at the source of power. The reason is simple. If you have a ground fault, that is, the black or white is touching something it shouldn't, the circuit needs a low resistance path back to the source (the green wire) or it just might go through you.
So if you have a power cord from your generator that plugs into your normal AC Shore inlet, or the power cord is properly wired directly (hopefully through a transfer switch) to your main panel, then the green wire has a path back to the source. That is how permanently installed generators are wired into your boats electrical system, and how permanently installed generators ashore in houses, businesses and RV are installed. However, if you just plug your portable into the system or wire it in not through the main breaker panel, you may be creating a hazardous system that does not have a necessary path back to ground through the green wire. Unfortunately I have seen a lot of people do this running extension cords into their boat to run appliances and AC. It feeds back into the system and creates shock hazards and fire hazards. If you wire it correctly then it is safer.

Anyway. I have a paper on my web site that explains my feelings about using portables on boats and you can read it if you wish. https://newboatbuilders.com/docs/portable.pdf

[team karst]

Originally Posted by Ike

…,
In the world of marine electrical systems the word ground and the word grounding have two different meanings. AC wiring uses a three wire system, the black wire is the hot wire, the white is the neutral (but also hot) and GROUND wire, and the green is the safety GROUNDING wire.
…
Anyway. I have a paper on my web site that explains my feelings about using portables on boats and you can read it if you wish. https://newboatbuilders.com/docs/portable.pdf

I would say White/neutral is GROUNDED wire. But not call it “Ground”. Confusing to many, I suspect.

[Rumrace]

I have no emotional attachment to my generator. I do have feelings towards my Onan mechanic but off topic.
The two wire solar panels on my boat are more likely to start a fire or electrocute someone than the brands of portable generators we are discussing.
Opinions don’t count if you don’t intend to use one or have not used one.
I’m not a Honda fan of anything. I think they have set the bar on safe quiet portable generators. It has built into it as required by code shut offs to prevent everything we are imagining. They tell you not to run the generator inside your boat just in case you are special stupid. They tell you not to leave it running in the rain and will shut itself off in a rain storm. This is the only risk or electrical danger other than the condition of your boat.
Problems from portable generators on boats are related to demand and capacity.

The ground fault is built into your boat in several locations. The first one is your shore cord port the next ones are in the GFI outlets which are the only outlets allowed on a boat.
Just cause you have a 2000 watt Honda and 1800 watts of demand and want to charge your 4 Old ill maintained batteries at the same time!!?? Most small boats using a portable do not have a charging system to handle their demands as they pile household conveniences on the boat.

If you want to find fault in portable generators use, its with the owners not the products.

I was really exited to get a boat that needed two batteries. Now with 7 batteries worth more than my first boat I’m thinking of trading it in buying a canoe and avoiding these debates.