Pure Sine Wave generators

[Bluewaters2812]

Hi folks, I have read a lot of posts and responses regarding generators. I was just wondering whether for cruising purposes it is necessary to have a petrol driven pure sine wave generator to provide ac? I ask this because I am aware that the wave signal from anything other than a pure sine wave generator is not constant and subject to fluctuations that can wreak havoc on some circuit boards?

Can anyone tell me whether marine systems have a built in system to prevent electrical systems from becoming damaged and "even out" the current that is produced by a normal generator. Forgive me if I sound stupid asking this but I thought that if I didn't ask the question it would be more stupid.

[mbianka]

Originally Posted by Bluewaters2812

Hi folks, I have read a lot of posts and responses regarding generators. I was just wondering whether for cruising purposes it is necessary to have a petrol driven pure sine wave generator to provide ac? I ask this because I am aware that the wave signal from anything other than a pure sine wave generator is not constant and subject to fluctuations that can wreak havoc on some circuit boards?

Can anyone tell me whether marine systems have a built in system to prevent electrical systems from becoming damaged and "even out" the current that is produced by a normal generator. Forgive me if I sound stupid asking this but I thought that if I didn't ask the question it would be more stupid.

By marine systems I assume you mean your boats wiring. In that case the answer is no. The wires are just the delivery system for whatever generator you feed them with. If you are using a generator with a spikey or stepped AC signal and feed sensitive electronic power supplies like those used for computers etc... you are asking for trouble. For me having a Honda 2000i generator with it's smooth inverted sinewave output solves a lot of problems. For one thing I don't feel the need to install an 12 volt to 120 volt dc inverter on board. I often power my laptop at the same time I might be topping up the batteries. I'm also using it to use 120 volt power tools on board for projects. I'm also thinking about using it to power a small counter top toaster oven or microwave and not using the propane oven. Buying an electronic inverter to handle those loads is an added expense I don't really feel the need to do. Not to mention the added complexity those inverters add to a boats system and potential failure modes. So yes I think have a pure sine wave petro generator on board is a good to have on a cruising sailboat. My recommendation is for one of the Honda products. It has been very reliable for me though one word of caution:
THE BIANKA LOG BLOG: RELIABILITY: So much for that!
So just make sure you put some anti corrosion paste on the exposed outside screws (on whatever generator you use) so you can remove them when you need to for servicing.

[ksanders]

Originally Posted by Bluewaters2812

Hi folks, I have read a lot of posts and responses regarding generators. I was just wondering whether for cruising purposes it is necessary to have a petrol driven pure sine wave generator to provide ac? I ask this because I am aware that the wave signal from anything other than a pure sine wave generator is not constant and subject to fluctuations that can wreak havoc on some circuit boards?

Can anyone tell me whether marine systems have a built in system to prevent electrical systems from becoming damaged and "even out" the current that is produced by a normal generator. Forgive me if I sound stupid asking this but I thought that if I didn't ask the question it would be more stupid.

OK, I'm a generator technician by trade so here it goes.

In general a permenantly installed engine driven generator will produce a a pure sine wave. That is a function of the electromagnetics of the spinning generator end. I use permenantly mounted carefully because that separates them from the portables, and for good reason.

Any permenantly mounted marine generator will produce voltage suitable for normal boat loads including electronics. That is because a permenantly mounted generator generally has enough mass and a robust enough governor to overcome fluctuatuions in load which cause fluctuations in RPM. They generally also have good voltage regulation circuits that keep output voltage stable.

The portables are another story. The problem is that in general a portable generator does not have the mass or a good enough governor to control engine rpm with quickly varying loads. They are also generally capacitor regulated which does not provide quick response times and can produce poor voltage regulation.

The industry solved this several years ago with honda being the first I think. They went to a situation where the generator produces a DC voltage and the generator has a onboard inverter which produces a pure sine wave. These portables produce voltage that is on par or even better than much larger generators.

[David M]

There are inverters that are close enough to being a pure sine wave that they cause no problems with AC powered electronics. I run all kinds of very expensive oceanographic related electronics, sensors and computers from a pure sine wave inverter and have never had any problems. My two 12 volt alternators provide enough current to power all of the boats AC and DC loads, therefore I do not need a generator on board. On rare occasion when I do have equipment brought on board that is going to max out or come close to maxing out my alternators, I will bring a Honda generator onboard to supplement the electrical load. In my experience the Honda generators sine wave is close enough to work on all of these additional electronics, so far. The Honda generator has an inverter and not an AC motor for producing AC current.

[Bluewaters2812]

Originally Posted by mbianka

By marine systems I assume you mean your boats wiring. In that case the answer is no. The wires are just the delivery system for whatever generator you feed them with. If you are using a generator with a spikey or stepped AC signal and feed sensitive electronic power supplies like those used for computers etc... you are asking for trouble. For me having a Honda 2000i generator with it's smooth inverted sinewave output solves a lot of problems. For one thing I don't feel the need to install an 12 volt to 120 volt dc inverter on board. I often power my laptop at the same time I might be topping up the batteries. I'm also using it to use 120 volt power tools on board for projects. I'm also thinking about using it to power a small counter top toaster oven or microwave and not using the propane oven. Buying an electronic inverter to handle those loads is an added expense I don't really feel the need to do. Not to mention the added complexity those inverters add to a boats system and potential failure modes. So yes I think have a pure sine wave petro generator on board is a good to have on a cruising sailboat. My recommendation is for one of the Honda products. It has been very reliable for me though one word of caution:
THE BIANKA LOG BLOG: RELIABILITY: So much for that!
So just make sure you put some anti corrosion paste on the exposed outside screws (on whatever generator you use) so you can remove them when you need to for servicing.

Ah, ok, got it. I guess the Honda sine wave inverter generator is the way to go, thanks.

[denverd0n]

I would not try to talk you out of a Honda generator. I hear they are very good. I will say, though, that I routinely run my laptop with a very cheap, square wave inverter and have never had any problem at all. I have also used that same inverter to run a microwave oven, TV, stereo, and various small power tools.

Some people will tell you that this is impossible. That you cannot run a computer, a TV, a stereo, or a microwave with anything but an expensive, pure sine wave inverter. Well, I must have the magic mojo then, because I have done it.

I'm not saying that pure sine wave is bad. Obviously it is not. In fact, for many things it probably is absolutely necessary. I just haven't figured out exactly what those things are yet, as I don't seem to have any of them in my life.

[skipmac]

Originally Posted by denverd0n

I would not try to talk you out of a Honda generator. I hear they are very good. I will say, though, that I routinely run my laptop with a very cheap, square wave inverter and have never had any problem at all. I have also used that same inverter to run a microwave oven, TV, stereo, and various small power tools.

Some people will tell you that this is impossible. That you cannot run a computer, a TV, a stereo, or a microwave with anything but an expensive, pure sine wave inverter. Well, I must have the magic mojo then, because I have done it.

I must have the same mojo because I ran a laptop on board for months with a cheap square wave inverter and no problem. Also used to charge cell phones and two additional and different brands of laptop when I had crew on board and no problems so it wasn't because I happened to have a special laptop.

But I still like the Honda.

Originally Posted by denverd0n

I'm not saying that pure sine wave is bad. Obviously it is not. In fact, for many things it probably is absolutely necessary. I just haven't figured out exactly what those things are yet, as I don't seem to have any of them in my life.

Some AC power tools and other things that use certain types of electric motors don't like dirty power and will overheat and possibly burn out the motor.

[scorpio49]

i live off the grid in southern baja.for over 2 years i used a honda 2000i generator to power my home.everything worked smoothly.very reliable genset. a few months ago it was stolen so i've been sharing power with my neighbors 5500 watt gen with no inverter.my ceiling fans now have a different sound as if they are struggling with the input.i'll be ordering a new 2000i tomorrow morning when my pension is deposited.as far as i'm concerned,the honda is the only way to go.

[Bluewaters2812]

Originally Posted by scorpio49

i live off the grid in southern baja.for over 2 years i used a honda 2000i generator to power my home.everything worked smoothly.very reliable genset. a few months ago it was stolen so i've been sharing power with my neighbors 5500 watt gen with no inverter.my ceiling fans now have a different sound as if they are struggling with the input.i'll be ordering a new 2000i tomorrow morning when my pension is deposited.as far as i'm concerned,the honda is the only way to go.

I know that motorhomes in the UK (small version of an RV), cannot be run with a generator that does not have a sine wave inverter as it will blow the circuit board because of the fluctuation in supply. I don't know whether this is applicable to marine vessels but I would be very reluctant to have a generator that is not "smoothed" out with a sine wave inverter. I am not experienced in this so I am still waiting for a more experienced sailor to give his 2 cents worth on this topic.

[Bluewaters2812]

Originally Posted by skipmac

I must have the same mojo because I ran a laptop on board for months with a cheap square wave inverter and no problem. Also used to charge cell phones and two additional and different brands of laptop when I had crew on board and no problems so it wasn't because I happened to have a special laptop.

But I still like the Honda.



Some AC power tools and other things that use certain types of electric motors don't like dirty power and will overheat and possibly burn out the motor.

I am a computer technician and I reckon you are very lucky that a non sine wave inverter didn't fry your laptop. It probably didn't surge too much. I wouldn't risk my computer equipment with a generator that is not smoothed out. Perhaps marine craft have some sort of inverter that is built in and does this?

[Dsanduril]

Most laptops (cell phones, tablets, etc.) use universal input (110-240V, 50 or 60Hz) switch mode power supplies. It's really the power brick you are running from the inverter/generator, not the device itself. And if the brick has a universal input then there's about a 98% chance that it is a switch mode power supply. Switch mode power supplies really don't care about pure sine, modified sine, or square wave. They will rectify all of the above to DC for your device just fine. That's why the manufacturers use them, they will run just about anywhere. No need for anything fancy.

On the other hand, audio systems, cordless tools/chargers, and some other systems use either linear or capacitor based power supplies. These will get very unhappy on non-sine waveforms.

So, if all you are running is consumer electronics with a universal input power supply/brick you can probably run a messy generator/inverter. If you are running single voltage devices then you need to know what kind of power supply is used. One caveat to that, in the EU all power bricks over 75W are supposed to use power factor correction, and that usually entails capacitors, and you end up with a hybrid system. These will usually run OK on non-sine forms, but may run warmer depending on how far away from sine the power is.

[skipmac]

Originally Posted by Bluewaters2812

I am a computer technician and I reckon you are very lucky that a non sine wave inverter didn't fry your laptop. It probably didn't surge too much. I wouldn't risk my computer equipment with a generator that is not smoothed out. Perhaps marine craft have some sort of inverter that is built in and does this?

The Honda EU2000i or whatever model number for the European version, from most reports I've heard puts out very clean, pure sine wave. That's what I plan to buy when I'm ready to take off. If I had one now I would hook it up to an oscilloscope just to see.

I would be happy to run full trials and send you my evaluation if you want to send me a test unit.

[Captain Bill]

I can't speak directly about non-sine wave generators, but I can tell you that the wave form makes a difference in a number of appliances. We have a modified sine wave inverter and a traditional AC genset which of course puts outa pure sine wave. Our ice maker will not make ice on the inverter, though it will keep things cold. Our microwave requires about 25% more cooking time on the inverter so it's pretty obvious that the sine wave form does affect the output. Also certain solid state dimmer/temperature contol circuits will completely burn up on a modified sine wave. We tried using an electric blanket to pre-warm our bunk while sailing in the winter. I noticed a smell of burning electronics. When I found the source it was smoking, but had not burst into flames yet. Needless to say that was the end of that control. I later found a warning about using the blanket on a modified sine wave power source.

[delmarrey]

Originally Posted by skipmac

I must have the same mojo because I ran a laptop on board for months with a cheap square wave inverter and no problem. Also used to charge cell phones and two additional and different brands of laptop when I had crew on board and no problems so it wasn't because I happened to have a special laptop.

But I still like the Honda.



Some AC power tools and other things that use certain types of electric motors don't like dirty power and will overheat and possibly burn out the motor.

My bread maker will not run on a modified sine wave system but the TV, DVD, electric drill motors and lots of other AC stuff seems to work OK.

[Bluewaters2812]

Originally Posted by skipmac

The Honda EU2000i or whatever model number for the European version, from most reports I've heard puts out very clean, pure sine wave. That's what I plan to buy when I'm ready to take off. If I had one now I would hook it up to an oscilloscope just to see.

I would be happy to run full trials and send you my evaluation if you want to send me a test unit.

He he, when we win the lotto we will send you a new Honda Jenny.