August 26, 2011

Portable Generator: How to Use it Safely

If you just bought a portable generator set (genset) in wake of approaching Irene hurricane, and don't have time to read the entire manual, here are some crucial things you need to know. This quick safety checklist can save your life and lives of everyone in your home.

  • Portable generators produce carbon monoxide (CO). CO can kill in minutes. More than three hundreds people died in US during power outages from generator related CO poisonings. Therefore a portable generator can be run only outdoor with exhaust away from your home. EPA recommends to locate gensets at least 10 feet from the home You should also allow at least 2 feet of clearance on all sides of generator for adequate ventilation.

  • Most commercial portables are not weather proof. They pose the risk of electrocution and shock when used during a rain. Therefore, cover your genset in advance since Irene hurricane will be accompanied with heavy rain. It is not recommended to run a genset during a rain. If you are absolutely positively need to use a portable generator during a rain, build an open canopy-like structure. Don’t’ touch a genset with wet hands.

  • A portable generator should not be connected directly into your house wiring without a special two-pole changeover switch or an interlock, since otherwise you will be feeding electricity back into the utility lines. This would present a hazard for linemen and your neighbors. Portables are intended to be connected to your appliances primarily via separate cords. If you did not get a chance to install a transfer switch, prepare heave duty outdoor-rated cords with sufficient length. These cords should be long enough to reach your appliances through the windows or open doors.
For general operation theory, selection information and my picks, see this guide to portable generator.
This post is not a professional or a legal advice- I assume no liability of any kind for the accuracy of the above information.

August 1, 2011

New Auto Gas Mileage Standards

President Obama recently unveiled a plan to sharply increase auto fuel economy. The proposal would require the companies to reach average fuel efficiency across their U.S. fleets of 54.5 miles per gallon by 2025. The good news this would lower US oil use by 2.2 million barrels a day over the next 15 years, and accordingly cut the amount of money flowing to OPEC. It would also cut more than 6 billion tons of carbon emissions during this period of time. The bad news is according to The Center for Automotive Research, this requirement cost about $6,700 extra per car. It is also absolutely obvious that in order to achieve such fuel efficiency, the automakers would have to make the cars much lighter. Lighter cars of course are less safe. In a head-on collision, a lighter car will always have larger change in velocity due to Conservation of Momentum law (see Hyperphysics Concepts). So, no matter what anyone tells you, new fuel economy standards will hurt vehicles safety simply due to the laws of physics, even though the new cars may meet National standards for car crash safety. The trick is, during the compliance tests the car is being crashed against a still wall. Properly designed lightweight cars can perfectly pass these tests and claim five-star safety rating. However, they will have an obvious disadvantage in real conditions if collided with heavier cars. If more fuel-efficient cars offer us, the consumers, a true advantage, why mandate it? Should not their production and sales be driven by the market forces?