Portable Generator

[flyingvan]

OK. 

This is the sound pressure level meter I borrowed (close to it at least)
With the enclosure all opened I get 74db right next to it.  I get 60 at the house, and 30 inside at the nearest point.
With it all closed up I get 58 next to it, 40 and fluctuating at the house and 20 inside, which is about the same with the generator not running even though I can hear it.  I imagine there's a fair amount of ambient noise I tune out like my own breathing, the fridge, etc....In any event it's acceptable noise level inside and not bad outside.

[flyingvan]

  SDG&E shut off the grid power.  We had record wind gusts---101 MPH!  They got blamed for the Witch Creek Fire in '07 (true, the point of origin was one of their powerlines but when it's that dry for that long the fire's gonna start somewhere no matter what)  In any event they don't want to get blamed again, and partly out of sour grapes I think, when it's windy they shut off the power.
  Also when it's windy they won't let me leave work with the high fire danger.  AnnaMarie was well coached on starting the generator and had power all day when no one else did, and everything worked as designed.  She remembered to push the choke in after it started which was my biggest fear. 

[MountainDon]

 

[flyingvan]

http://www.youtube.com/watch?feature=player_embedded&v=jkO9PK4JvJI

[hpinson]

Gosh, thank you for the reminder.  Everyone should watch this. 

[MountainDon]

Good video post. 


I guess that's why I placed our generator 30 feet away from the house and off the end of the house with no doors or windows.      And a small shed between the generator in the barn and the house.

[Adam Roby]

That video definitely makes me reconsider putting the generator under my deck.  I wonder of extending the muffler straight up over the roof height would be sufficient to get the gases to a safe level, or if there is also gas leaked from the engine bay that could be dangerous.  I would think the majority would come from the muffler...   I think I need to consider a plan B.

[MountainDon]

There is an exhaust extender system that is sold for use with large RV's. It directs the exhaust up to above RV roof top. It has an air inlet at the bottom as well which draws air through the outer sleeve (IIRC) and that cools the sleeve. From what I have read they work well for that purpose; no noxious fumes floating around at ground level.

[UK4X4]

We had issues with our RV generator and monoxide as well, we added a 2" 8ft long plastic tube and moved the exhaust the other side of a wood pile.

We had a battery detector and the RV mains one, the bedroom one went off first and then the main room as the gas filtered in.

the RV was positioned in a corner of the plot with a wood pile alongside, the wind was low and I think the exhaust was pooling in the corner beneath the RV.

Its definitely a killer, and needs a lot of thought when using gas powered generators

[flyingvan]

  I've responded to a few CO poisonings over the years---maybe here is a good place for a soapbox rant.

   CO is lighter than air by a little.  It really likes to drift around but won't dissipate as quickly as some of the other LTA gasses.  Poisonings are insidious---your hemoglobin has 250 times the affinity for CO as it does for oxygen so you get a cumulative effect.   Maybe you ran your generator yesterday and everything seemed fine, but now you're starting your saturation.  You run it again...Eventually you displace enough oxygen that you get into problems.   If you smoke, overhaul fires, work in a garage, barbeque, vent free heater, etc.  it all adds up. 
   Symptoms are light headedness, confusion, headache, flu symptoms.  Chronic exposure brings its own risks.  You've probably heard of the 'cherry red skin' symptom---that's a pretty late, and ominous, sign, so don't rely on it.  Besides, detectors are cheap.
   High flow O2 and hyperbaric therapy are the treatments of choice---but avoidance is the safest, easiest and best policy. 
   There's a theory that reports of haunted houses are rooted in CO poisonings---there's a faulty heating unit somewhere, and the residents start hallucinating....
    I really like the newer wood stoves that introduce some outside air into the house to maintain a slightly positive pressure.  THis drives out the CO from pilot lights, gas ranges, dryers, any other source.  On a cold night with your heat source going, the range hood and bathroom fart fan on, then close your whole house up tight.  Get a single square of toilet paper and open the front door just a crack and drop the toilet paper sheet right next to it---if it sucks into the house, you're likely concentrating CO in the living space.  If your generator is too close it can find a way in....(This wasn't much of a problem in the old drafty houses but as sealing and insulation techniques advance we're building houses much tighter.  Air flow MUST be accounted for)

[MountainDon]

-your hemoglobin has 250 times the affinity for CO as it does for oxygen

I have read that once a red blood cell picks up CO it does not let it go.  That cell has to die off and be replaced before the CO leaves you.

http://scienceline.ucsb.edu/getkey.php?key=1856

The lifespan of a red blood cell is about 115 days.

It is possible to reach so high a concentration of CO in the blood that being placed on pure oxygen can not save your life because there are insufficient red blood cells that can accept oxygen.  So be careful and do all you can to avoid CO.

[Adam Roby]

You have to wonder how many of us think we are safe when in fact we are not.  I will spend the extra money for longer wires if it means keeping myself and my loved ones safe.

[MountainDon]

You have to wonder how many of us think we are safe when in fact we are not.

The crowd that loves to use non vented heaters and cheapy on demand water heaters meant for outdoor use probably lead that pack.

[Adam Roby]

I am sure there are some that refuse to believe, but there are probably many more that just don't know any better.  Not out of spite or not wanting to be safe, our of sheer lack of knowledge.  That is where these forums become a world of useful information.  I don't care how silly I sound asking some of these questions, because I know there are probably a few others out there with the same questions who can also benefit.  I will eat my humble pie many times before I finally build my tiny cabin... and hopefully I will make all the right choices based on everyone else's experience. 

[flyingvan]

Years ago I worked in hyperbaric medicine.....There was an interesting demonstration where you used pheresis to remove all the red blood cells from a sedated pig down to 6 atmospheres.  The hemoglobin alone will carry enough oxygen to sustain life at that pressure.  The pig was white though.  Dr. Bayne told me the O2 would displace the CO which was squished down under pressure, I never thought to really question him and I know the chamber was a life saver for CO poisoned people.  You got me curious again and I'm going to research whether red blood cells re-liberate CO or not

[flyingvan]

Another 'generator milestone'....Once again I was at work when the power went out.  My wife just started up the generator and threw the power transfer switch and went about her business.  Hours later she called, I didn't even know the power was out up the hill.  This is exactly the scenario the unit was installed for

[MountainDon]

 

[flyingvan]

Just a small side note I've been meaning to post about generators....

   Even though this is a 'portable' unit adapted to permanent standby use, I insisted on a 240 volt model.  Reason being, I didn't want to overload any white wires anywhere...
   I could have bought a 5KW generator that produced 120V for less $$ and just fed both hot legs in together since nothing in the house is 240 volts...But I might send 4800 watts at 120 volts through that common, at 40 amps.  By keeping two legs at 120 for each leg some returns through the opposite leg and the only thing the neutral carries is the imbalance between the two legs, so no overload

[flyingvan]

   Got a little upset at my generator...Once again SDG&E shut off the power during a 'wind event'--they don't want to get blamed for another wildfire.  Gen started right up but the lights were feeble.  Motor sounded fine.....The LCD display on the generator showed 60.2 Hz but only 80 volts.
    Once I realized it had given 5 years of problem free service it was a little difficult to stay upset.  I took things apart and looked for any obvious loose wires, all looked good.  Called the manufacturer---the guy who answered wanted me to check dirty fuel (only burns propane) low oil etc, nothing that would cause undervolt.  He told me to take it to a repair shop, get their diagnosis, then order parts. 
     THAT would be an endeavor---taking it out of the housing, all the connections, driving it down...  "How much is a new voltage regulator?"  "You don't want to just go replacing parts until it's fixed.  You'll be sorry".  "OK but how much is a new voltage regulator?" $40.  Sold, send it.
    Received, installed, 118 volts.

[Nate R]

Nice job on that one!

[JRR]

Did I just miss it, or was there any comment/comparison of CO emissions of propane vs gasoline as fuels ...??

[flyingvan]

https://www.nettinc.com/information/emissions-faq/how-clean-are-lpg-engines

   Like most answers here---"it depends'.  A perfectly running propane engine will make Perrier.  You take C3H8 and completely burn it, you end up with H20 and CO2.  BUT.....
   If you are running rich, you can make a lot of CO.  If you want really low CO, get a diesel generator.  The mercaptan (odorant, a thiol) they add also makes a slight pollutant--Again, Perrier, but with a little sulfur dioxide in it. 
   How bad are sulfur compounds?  Pretty much anything smelly is a sulfur compound.  Skunk, a freshly opened beer, volcanoes, farts---all sulfur compounds.   Fortunately nature provides microbes that love them.
   Now gasoline---gasoline exhaust is far more complex.  Gasoline is a literal hydrocarbon soup, with all sorts of additives.  You get some nitrogen oxides you don't see in propane.  Usually more CO also and some unburned hydrocarbons.  That said, a perfectly running gasoline motor poses less a health risk than a poorly maintained (or not adjusted to altitude) propane model.

   Two points from my soapbox---

1) Whatever sustains you ultimately kills you
2) EVERYTHING is a poison.  It comes down to dosage.

[Dave Sparks]

Propane is also often available in rural areas from large tanks at the house, and the commercial people can fill tanks from a 120 vac generator when the town or area is evacuated. During this time the power is shut down for days, usually a wildfire causes this and they cut power to get you to leave.
If the tank has a liquid line valve, you can fill your own tank about 1/2 without the compressor running

All the gasoline generators can't get gasoline because the power is out.

I made a small fortune lending out my propane generator for 7 days when our town was evaced.  I keep it for customers.

The usual  good things about propane are not having to worry about diesel growing algae and gasoline turning to varnish.

The fire guys always ask if we are leaving and I tell them "your usual parking place is saved and we will be barbecuing" You can sleep on cots in the garage and get out of the smoke.

[flyingvan]

Dave---any guesses on why my AVR would have failed?  It's a completely sealed unit.  I was NOT in the habit of letting the generator run for a bit before throwing the power transfer switch, maybe 20 seconds or so

[Don_P]

If I can tag onto that question, a friend had a generator putting out 90 volts this winter, there was a capacitor fried, easy fix but also why?

chemistry question, If I run a generator on CO, a charcoal gasifier, is it simply producing CO2. This is also a way to generate when the grid is down, I can always make charcoal.