Generator sine wave(s)

Thurman · 07-29-2015, 10:13 AM

I hear and read a lot about how certain generators produce "pure sine waves" and other generators produce "modified sine waves". Then I read where the modified sine waves are not good to use with RV's. There seem to be problems with certain appliances, TV's, and A/C units going bad while running on AC current produced by modified sine waves. I have a generator but have no idea of what type sine waves this generator produces. How does one find out which type sine waves a generator produces?

**Flybob** · 07-29-2015, 10:19 AM

Please post model number. Is it an inverter generator?

Jim Schings · 07-29-2015, 10:29 AM

I may be wrong, but I think all generators that we would have installed are sine wave (pure). Anytime power is generated via mechanical motion it is pretty close to a sine wave. The only issue we might have, is FREQUENCY variations. We want something close to 60 hz, but nothing in the RV cares to much with a variations of up to 5 HZ.

Where sine wave (pure) and sine wave (modified) ARE an issue is with Inverters. (devices converting from 12V DC to 120V AC). It is easy to design and build a modified sine wave output. Thus those units are cheaper. However, they are noisy (electrically) and can interfere with other devices and CAN put extra strain on the powered components of some devices. A few may not even work properly...

A pure sign wave inverter is far safer and more expensive. As far as determining whether a device (gen or inverter) produces a sign wave you would need a scope (oscilloscope). A trivial test, but you need the scope first. Also a frequency meter would give some indication of the differences, but wouldn't be fool proof.

Thurman · 07-29-2015, 10:32 AM

I have no idea if it is an "inverter generator". The generator is a TROY-BILT model 019919-1 rated at 5500 watt running and 8500 watt start-up. I've used this generator on jobs to run saws, drills, sawzall's, etc. but never with my camper. I have the opportunity to go boondock camping in two weeks and would like to try camping with the generator but don't want to harm any electrical anything's.

Jim Schings · 07-29-2015, 10:36 AM

After a quick search, I see what are called (inverter generators). Since I have not fooled with (other than use) someone straighten me out. These inverter gens put out some form of DC and then it is inverted to 60hz AC ?

Jim Schings · 07-29-2015, 10:47 AM

Thurman, Looked you unit up. In any case, it IS safe to use on any of your devices. It puts out a 60 hz sine wave.

**Flybob** · 07-29-2015, 10:53 AM

The generator you have is commonly called a construction site generator. It uses a mechanical alternator to generate a good sine wave but freq can vary with load. The generators that are either pure or modified sine wave, are inverter generators. The convert DC to AC using an inverter. Modified sine wave inverters are less expensive and basically create more of a square wave which is Ok for many things, but can cause issues in some appliances that require cleaner power. pure sine wave inverters are more expensive and create power much closer to but not a sine wave. The mechanical generators like you have actually create a more accurate sine wave, The issue is that construction generators are very noisy and not allowed in many areas.

Thurman · 07-31-2015, 10:48 PM

"Jim Schings"--Thank You for that information, I do appreciate you taking the time to find that info. I called myself looking on the 'net but did not find that info. "Flybob"--Thanks to you also for your info, and YES this generator is noisy. We are invited to a B-B-Q cook-off that is on a man's farm so no hook-up's at all. I feel that we will be fine with my generator.

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