cc to HP conversion

OK, I agree that Honda is the way to go, however, $$ does enter the picture. The Generac is $449 with free shipping. A Honda EG series 3600Watt is $999 and you pay for shipping (Northern Tool catalog, page 12. Or there's a Honda EM series 3800 watt at the "discount price" of $1899.

My application is purely emergency use when we get an ice storm and lose power for up to 7 days. This has happened twice in the 5 years since we built the new house here. Odds are it'll happen again this winter or next. Would be nice to keep the frig and freezer running and perhaps use the internet. Oh, from amp readings taken at the load center the start up current for both is 24 amps which is about 2800 Watts so that's within the size of the unit I'm considering.

Looking at my GT 500 it has a 724 cc also marked 26HP, so doing that math, 27.84 cc/HP. Again, looking at the Northern catalog, page 11 there are three honda generators 3800, 5000, and 6500 watt, so that's 30.25, 30.63, and 29.92 cc/HP respectively. So, it would seem that 27-30 cc/HP is in the ballpark for these engines.

Going back to the Generac at 207 cc and dividing by 27 = 7.6 HP.

Now, I'm starting to realize that this is trying to compare apples to rhutabagas or something. However, the Honda EM series 3800 watt has a 8HP (242cc). So a Honda has a 8HP @3500W and Generac has a 7.6HP @ 3250W so it's at least in the ball park.

What other generator would anyone recomend in the 3250 watt size? Yep, I know Honda is a wonderful machine, much quieter, longer lasting, etc. This is for purely emergency use probably once a year.

The research I've done on Generac is that they're a reasonable machine and if you buy a Briggs portable generator, it has a Generac engine not a Briggs. (that's a fact that I'm still trying to get my head around....) They manufacture their own engines and generators here in the US. The Generac has low oil cutoff, circuit breakers, wheels, and a handle for maneuverability.

Apologies, I guess I answered my own question by looking around here-maybe a moral there somewhere? However I am interested in any recomendations on generators or if anyone has had bad experience with the smaller Generac units.

Thanks for your time,

Ev

Since this has expanded beyond my original question into more of a "dos and don'ts" on emergency generator use, I'll add something. Specifically, it's absoloutely critical to GROUND THE GENERATOR!!!! When you're deciding on where to put it, etc. etc. make sure you have a ground available for safety. I plan on running a separate ground back to the "driven ground" at my service entrance just for this unit. This is a small unit, 3750 surge capacity, but that is big enough to fry a lot of eggs-or people...:-(

Lack of grounding could also play into some of the frequency issues discussed. I've emailed Generac to see what the frequency variation on this unit is. I do know that all the EMS tower sites around here have Generac generators installed usually without a UPS. However, those are the 8KW, auto transfer, propane units and comparing that to their (almost) bottom of the line (KW) unit wouldn't be smart.

Generally home computers are "speced out" to survive wherever people do in terms of temp, humidity, and have a pretty wide window when it comes to voltage and frequency. The problem comes in when you go under the minimum voltage levels, throw in some frequency variation and you're definitely looking for trouble. e.g. you're keeping the frig running, a few lights, and decide to check email. Most "charts" which tell you how much power you'll need indicate arund 800W for a frig or freezer. I would suggest that these numbers go back to some previous age. My house and appliances are almost 5 years old and both the frig and freezer run at 200w and 140w respectively. However, their starting loads are 1680 and 1200 respectively, so the 800W does cover their normal power consumption, but is way under their starting requirements. If you've sized your generator based on 800w, and then a 1680 load comes on, output voltage and frequency will be significantly diminished. If you're checking mail or something, this diminished voltage and frequency would go below the "specs" for the computer and damage could result.

In sizing this unit, I took actual measurements at the load center with a clamp on ammeter to determine what MY system loads are, not a chart on someone's website. Suggest you do the same.

Sequencing also comes into play, Power has been off for a while, time to start the generator, plug in the frig, it starts, generator picks up 1680W load and then settles to 200W load, add in freezer, 1200W load, then diminishes to 120W. Now wer're running at a steady state 320W-from a 3250W source so can plug in computer, tv and continue with life as we know it. The frig and freezer, having been off for a while, should just continue to run bringing temps back to where they should be. One other area to be very wary of is microwave ovens, they can easily run at 800-1000W and that's steady state which will definitely drag down your generators voltage.

Sorry, I got wordy on this one,

Ev