By Mike Sokol
Welcome to my J.A.M. (Just Ask Mike) Session, a weekly column where I answer your basic electrical questions. If you’re a newbie who’s never plugged in a shore power cord (or ask – what’s a shore power cord?), or wonder why your daughter’s hair dryer keeps tripping the circuit breaker, this column is for you. Send your questions to Mike Sokol at mike (at) noshockzone.org with the subject line —JAM.
You keep harping on how loud some generators are compared to others. I know the Honda 2000’s are quiet, but are they worth 4x the money of a regular generator I can buy at Home Depot? Does anyone really care about the noise? —Curtis
Well, I’m going to let you judge for yourself. I know that money can be tight, but I don’t think generators are the place to buy the cheapest product available. So here are the two basic designs along with a comparison of just how noisy they are. Don’t worry about the dB (decibel) numbers at this point as that’s an advanced topic that even my college students have trouble with. For right now, just listen and trust your ears.
The two basic types of portable generators are open-frame (contractor) and inverter (suitcase) styles.
Open-frame/contractor generators are less expensive and built to make as much cheap power as possible to run power tools at a job site, so they don’t have very large mufflers and there’s no sound insulation around them. Plus, they have to run at a constant RPM to make the proper 60-Hz power that all AC appliances in the U.S. are designed for. And because they’re always running at full speed, they also use a lot of gasoline. Not a big deal if you’re a contractor and already paying hundreds of dollars an hour for a work crew. You just want to get the job done, and nobody cares about generator noise when the crew is running a jackhammer.
Inverter/suitcase generators aren’t really AC generators at all. They actually produce 12 volts DC internally which they use to power their own sine-wave inverter to convert it to 120-volts AC at 60 Hz. Because of this the gasoline (or propane) engine doesn’t need to run at full speed all the time, and you can flip a switch that will let them throttle down to idle speed when you don’t need as much power. That saves fuel and noise at the same time. Plus these inverter generators have large mufflers and are encased in sound insulation. That’s what makes them 3 or 4 times the price of a cheap contractor generator. All that extra stuff costs money.
So what’s the difference in noise levels? For the full article I wrote about this last year along with a video showing calibrated deciBel levels, please go HERE. Or if you just want to hear the difference for yourself without thinking about the math, then simply watch and listen to the video below. Yes, I calibrated the video edits carefully with my crazy-expensive acoustic analysis tools, which is what I do and teach for a day job.
Would you want this contractor generator running anywhere near you in a campground? I didn’t think so….
So is there hope out there for someone who wants to be a good low-noise neighbor, but who can’t (or won’t) spend the big bucks on a Honda or Yamaha inverter generator? Well, yes, there is. I’ve been doing some looking at the Harbor Freight Predator inverter generators which are half the cost of a Honda or Yamaha genny, and while I don’t think they’ll have the decades-long lifespan of a Honda, they might be just what you need (and can afford) for your own boondocking power. But I can’t judge them on their specifications alone, so I’m asking Harbor Freight to send me one of their 3,000-watt and a pair of their 2,000-watt Predators so I can do a side-by-side noise comparison with my Honda EU2200 and EU3000is generators. This could take a month or more for them to send me product, but I’ll get them on the top of my to-do list as soon as they arrive. So, patience, please.
OK, everyone. Remember that electricity is a useful and powerful force, so use it carefully and wisely.
See you next week. Until then, let’s play safe out there….
Mike Sokol is an electrical and professional sound expert with 40+ years in the industry. His excellent book RV Electrical Safety is available at Amazon.com. For more info on Mike’s qualifications as an electrical expert, click here.
##RVDT 1108; ##RVT 899