Generator Question: Fuel Efficiency and Load

It depends on how long you want to run the generator for....Generators carrying a full load tend to overheat after a while, and must be allowed to cool down....This will shorten the life....Then you must consider fuel tank size, and how often it must be refilled...Refilling a gas tank on a red hot generator when you're half asleep is not a good idea...I don't like to exceed 75% load on a generator that is to be used continuously, and happier at 50%...Don't be penny wise and pound foolish as they say...

The 1500w is a HONDA cost a few bucks more than the 5400W that is Snapper with a Briggs. However, the only time that Honda ever did NOT start was when it was out of gas!

My bare requirements are pretty simple

NO AC.

NO HOT water

Frig and freezer alternately, two fans constant , kerosene lantern ( no power required)

Water well twice a day or so..... all by itself.

We have natural gas so we never lose the stove.

We lost power before Isaac was even on shore and stayed out for two days.

I ran the small one the first day and night and the big one the next day.

Just wondering which is better for long haul as this could have been a case where we would have been out for weeks...like in RITA, LILLY and ANDREW. Back then , I only had the HONDA. Before that we just burned kerosene and drank what water we stored in the 5 gallon cans....and sweated...sweated a lot!

What are folks' thoughts about those natural gas gen sets that hook up to your home and cut on automatically? Are they dependable?? Can you pick what to run on them?

I've installed a few of the Generac residential Systems with the gas feed, some natural some propane, they seem to work well but do require regular maintenance...You can wire these, with a failsafe switch, right into the main panel and shut some breakers off, or use a sub-panel(they come with a package)...This provides for a totally automatic system if you don't want to switch power around...I used 12 to 14k generators so the AC can be run, I mean what's the point of having it if you can't be comfortable? The systems can be had wholesale for about 2g's...

SE,

What usually goes out on those things.... or what kinds of regular maintenance?

I have a 5 ton AC, 220V hot water, frig, freeezer , washer and dryer 220V 50 Amps.... lights , computer, tv....nothing big. ( wife made take the welder out of the utility room and get my OWN 220V/50Amp breaker.. ha ha ).

So, what size would you think considering what I run ?

For all of that about 25 -30 Kw would be a good start.

Just starting your 5 ton AC compressor is going to take at least an honest rated 15 - 20 KW unit.

Well you have to decide what you want to be able to run at the same time....Ordinarily you would switch the AC off to run the dryer or the water heater or welder...The 5 ton AC would probably require 17kw...but what you can do is add up the watts of everything you want to run and figure out what can be run with what.... Now the motors, compressors require a starting surge which the generator can handle but you have to know the limits....The starting surge can be reduced with start caps installed, which you should already have....These units start up for 15 min a week to keep the unit in condition(If memory serves), so you have to check these systems on a regular basis to make sure everything is operational....This includes any maintenance that would be required for an engine, air filters, oil, plugs, electronics etc....These have computers that display error codes when a problem is detected, but it can't fix itself...

You can't beat a Generac genset!

Last year I sized one for my mom's house, a 12kW unit with auto-switchgear and fueled with NG. It also has an enclsure and critical exhaust....whisper quiet!!! She had it installed shortly after I gave her the specs. It'll power up the entire house (she has a lot to power up too!), plus a good part of the next door neighbor's house.

Every Monday at 1 PM is starts without fail, performs it's diagnostics and charges the battery.

Best thing she ever did to give herself piece of mind, especially for the Winter months and when she's away in Myrtle Beach at the condo.

Two separate items: 1. You can run the Honda at very close to max power for long periods. I've run some older Hondas throughout the night on breakdown sites (at around 90% of full load, powering HPS lights) without any problems. Be careful when filling though, the smaller units do not have large fuel tanks and must be refilled every so often. Hot days may present its own set of problems, though, so my experience does not cover that. I personally am not a big fan of older Briggs & Strattons, especially if run at full load, but some collegues swear by them.

2. I'm not familiar with natural gas for gensets (we don't use that over here really). Just make sure that in the event of disaster, you will still have adequate supply of natural gas. I'm worried that if you have a big natural disaster and you are using piped gas, then those supplies may be interrupted too. But if it is "bottled" and you can store enough, that should be fine too.

I'd say run them at no less that 30% and no more than 80%.

Whoa!..... then with those numbers I was really burning that HONDA pretty close.

Maybe a typo or whatever, but "1500w ( 5hp) ... or 5400w (10hp) ..." doesn't add up (or even multiply ).

The 5400W has a Briggs 10 hp

The Honda is a 2500W ( not 1500) and what I thought showed 5hp was something to do with the model... actually, it is so old, i do not see the sticker on it that shows the HP.

20K generac installed ( approx.) $4500 through $5500. ...plus installation as I am NOT tackling that.

I do not quibble on prices. Either i can or i can not. This looks like a can not.

Major storms which would leave us powerless for more than 5 days run about severy 5-7 years, .... 2-6 hour outage , 2 times a year.

My thinking is stick with what I have and live with the fans I use in the shop....neighbors staying with us this week asked for blankets as those 8000 cfm fans blow some air. During the big storms we all stay in the front room and kitchen anyway.

Folks don't like the Spartan conditions they can always hoof it to town and stay in a Red Cross shelter....or get their own set up. Correct?

I think the two i have now will work . I'll keep in mind the 30 low>>>80 high on useage.

Thank you all again.

Greetings.

I just got a bid from the Cummins Dealer in Renton, Washington the end of last year for a backup generator for the business where I worked.

The 22,000 watt propane generator was just over $5,000 and the Automatic switch was just over $1,000.

The generator comes in a weatherproof cabinet.

The advantage of propane is that the propane does not degrade like gas or diesel.

Thank You.

That is a very good price.

i would recommend a honda inverter generator. they're very effient and can be used to power eletronic equipment.

If the generator is rated for xx continuous amps, it can run there indefinitely. Efficiency tends to be best at full or nearly full load, but you need enough reserve to be able to start the largest motor. You will essentially be burning enough fuel to supply the loads, plus frictional losses in the generator. The bigger generator has larger frictional losses. Ergo....

i think that's the advantage of a convertor-generator. they're able to supply the correct voltage at a low rpm, depending on the amps needed.

Have you accounted for the frequency?

i think this unit is capable of producing a steady frequency. as i stated, it will power eletronic equipment.

the op needs to do his own research. i just gave him a basic recommention that he may want to check out.

"Efficiency tends to be best at full or nearly full load, but you need enough reserve to be able to start the largest motor"

As stated, the best approach then is to initially start or turn ON the largest motor first, before adding any additional loads to avoid tripping or 'overload' condition due to or as caused by surge starting current. Thereafter can safely turn other loads ON, up to maximum safe working limit or generator rated capacity?

That's OK if you manually control the loads, i.e. if there are no thermostats or timers or whatever turning things off and on.

I think you should work with 1500w generator because it is heavy.