Monthly Archives: May 2014
Saturday Song #135
Lullabies are where you find ’em. Mom used to sing this to me when I was a baby: Mairzey Doats
Food for Thought – 30 May 2014
What Is It? – The Answer
A couple of you were essentially correct: It is a resistor, or a current-limiting ‘shunt’, part of the protection network of my multi-thousand horsepower variable frequency drive.
Variable frequency? Yeah, three-phase AC motors are just about the simplest things imaginable: Iron, wire, ONE moving part. However, the simple ones have a single speed, fixed by the requency of the power system. My 7000 and 9000 horsepower units run at 1785 RPM, essentially 1800 RPM, which you can see is tied as a multiple to the 60 Hertz (used to be 60 CYCLES) frequency of the American power grid. If I want to vary the speed of that motor (and I do) then I need to be able to feed it something other than 60 Hertz.
We do this by turning the AC to DC, not a particularly difficult thing, then we use some transistors the size of paperback books to chop that DC up ind make the motor think it’s AC again. How fast we do the chopping controls what the motor thinks the frequency is, and it spins itself accordingly. That’s normal operation. The resistor int he picture has nothing to do with normal operation.
If the smart stuff in my drive sees a problem, it stops turning those transistors on. That takes care of stopping the motor. However, then I have all this DC electricity sitting there that I need to ditch. That’s where this resistor comes in. A protection circuit called a ‘crowbar’ (because it fakes the action of tossing a physical crowbar across two conductors, one negative, one positive) fires as an electronic switch and puts this resistor from the positive conductor to ground and from the negative conductor to ground. Bingo! The DC is gone!
Since these two conductors are 2000 volts to ground and they have some capacitors connected to them storing a charge, it’s a pretty good chunk of electricity. In practice, this resistor is in an enclosed cabinet, safe from being poked and prodded by curious dolts, but it still manages to gather a certain amount of dust. When the crowbar fires, that resistor gets hot really fast. Dust? Nope! Now it’s smoke.
The actual firing and discharge sequence takes a matter of a few thousandths of a second. It’s quite impressive.
And that’s just some of the fun stuff I get to play with.
Today in History – May 31
1678 – The Godiva procession through Coventry begins. Now there’s a tax protest.
1884 – Dr. John Harvey Kellogg patents “flaked cereal”
1889 – Johnstown Flood: Over 2,200 people die after a dam break sends a 60-foot (18-meter) wall of water over the town of Johnstown, Pennsylvania. FEMA slow to respond. Bush widely blamed.
1911 – R.M.S. Titanic launched. This will end well.
1916 – World War I: Battle of Jutland – The British Grand Fleet under the command of Sir John Jellicoe &Sir David Beatty engage the Kaiserliche Marine under the command of Reinhard Scheer & Franz von Hipper in the largest naval battle of the war, which proves indecisive.
1927 – The last Ford Model T rolls off the assembly line after a production run of 15,007,003 vehicles. The VW Beetle (Type 111) finally beat that production number, topping out at 21,529,464. 15,444,858 of them were built in Germany.
Today in History – May 30
1539 – In Florida, Hernando de Soto lands at Tampa Bay with 600 soldiers with the goal of finding gold, gets run over by an 83-year-old retiree from brooklyn who’s driving a full sized Lincoln with a seatbelt hanging out the door.
1783 – Benjamin Tower of Philadelphia publishes first daily newspaper in US.
1848 – Mexico ratifies treaty giving the Unites States most of New Mexico, all of California, parts of Nevada, Utah, Arizona, and Colorado in return for $15 million. We paid for it.
1868 – Decoration Day (the predecessor of the modern “Memorial Day”) is observed in the United States for the first time (By “Commander-in-chief of the Grand Army of the Republic” John A. Logan’s proclamation on May 5)when two women in Columbus Mississippi placed flowers on both Confederate & Union graves.
1896 – First recorded car accident occurs as Henry Wells hit a bicyclist in New York City. Three lawyers are injured in a scuffle over who gives the victim a business card first.
1937 – Memorial Day massacre: Chicago police shoot and kill 10 labor demonstrators. Now they’re just as likely to BE the labor demonstrators.
1958 – Memorial Day: the remains of two unidentified American servicemen, killed in action during World War II and the Korean War respectively, are buried at the Tomb of the Unknown Soldier in Arlington National Cemetery.
1968 – Charles De Gaulle reappears publicly after his flight to Baden-Baden, Germany, and dissolves the French National Assembly by a radio appeal. Immediately after, less than one million of his supporters march on the Champs-Élysées in Paris. This is the turning point of May 1968 in France. Even De Gaulle knows that the easiest way to get something going in France is to start out from Germany.
1971 – 36 hospitalized during Grateful Dead concert after drinking LSD-laced apple juice. Drugs? At a Grateful Dead concert? Shocked, I tell you. Shocked!
1972 – In Tel Aviv members of the Japanese Red Army carry out the Lod Airport Massacre, killing 24 people and injuring 78 others.
What is it?
So I hear the phone ringing in my office as I’m walking up the hall. I step rather sprightly (yeah… I can still do that) and see it’s a mechanical guy from one of my sites.
Him: I need some help.
Me: That’s what I’m here for.
Him: I have a part number. It’s for our electric unit, and it’s not a Solar (The compressor manufacturer) or Lufkin (The gearbox manufacturer) so I’m guessing it belongs to the electric side.
Me (thinking that the equipment in question has a thousand different parts): Give it to me.
Him: 821 62284-001. I think it’s a transformer. Tell you what. I can send you a picture.
Me: That would be great.
This is what I got. The geeks among you might be able to guess. If not, the answer will come tomorrow. (Clicking gets you a big one)
Took me zero time to identify. Hint: It’s NOT a transformer.
Food for Thought – 29 May 2014
Today in History – May 29
1780 – At the Battle of Waxhaws, Lieutenant Colonel Banastre Tarleton massacres Colonel Abraham Buford’s continentals allegedly after the continentals surrender. 113 Americans are killed. Nothing like a good massacre to show how you really feel.
1849 – Lincoln says “You can fool some of the people all of the time, all of people some of time, but you can’t fool all of the people all of time”. The dimmocrat party says “all you gotta do is fool enough to get yourself elected, then screw ’em all…”
1864 – Emperor Maximilian of Mexico arrives in Mexico for the first time. He has the full backing of the French government which naturally means he’s a despot, later executed by his own rebellious people.
1886 – Chemist John Pemberton places his first advertisement for Coca-Cola, the ad appearing in the Atlanta Journal.
1940 – The first flight of the Vought F4U Corsair. In the coming war, the Japanese called it “Whistling Death”.
1942 – Bing Crosby, the Ken Darby Singers and the John Scott Trotter Orchestra record Irving Berlin’s “White Christmas”, the best-selling Christmas album in history, for Decca Records in Los Angeles. Come Christmas time, it’s either this, or “Grandma Got Run Over by a Reindeer”.
1953 – Sir Edmund Hillary and Sherpa Tenzing Norgay are the first people to reach the summit of Mount Everest, on Tenzing Norgay’s (adopted) 39th birthday. Hillary Clinton, born in 1947, is, by her own words, named after Sir Edmund, who was completely unknown in 1947, which means she should be president.
1977 – Janet Guthrie becomes first woman to drive in Indy 500, completes first ten laps while applying mascara.
1987 – Michael Jackson attempts to buy Elephant Man’s remains, offering a slightly used Cub Scout troop and an undisclosed amount of cash.
Safe At Home
The electrical distributor called at 1030 to announce the arrival of our new circuit breakers. I went out to get them, got back, and started to work. I’d already pulled the draw-out assembly from an unused cubicle and prepped it for our new breakers. The station tech and I got the the new ones in place, we killed the two circuits that were affected by our work, and fifteen minutes later, the swap was complete. Total work? Maybe an hour and a half.
I think I found the (almost literal) smoking gun to explain the prematurely tripping breaker that initiated this whole exercise. While I was disconnecting the outgoing wires to the bad breaker, one screw was darkened by heat. It was also loose. The wire was making connection only due to its natural springiness. Generates heat, you know. And guess what causes these breakers to trip? If you said “It’s a ‘thermal-magnetic breaker’, so I’m guessing heat” then you win the lollipop. Not 100% sure, but it’s a good bet. No use trying to tighten things up and see if it works. I got gas to move. New breaker was only $900.
Six hour drive back home. In the door at 1830, took a cat count, all present and accounted for. Frozen meal for dinner. Now it’s down time.
Today in History – May 28
1588 – The Spanish Armada, with 130 ships and 30,000 men, sets sail from Lisbon heading for the English Channel. (It will take until May 30 for all ships to leave port). In a big hurry to get a butt-kicking…
1754 – French and Indian War: in the first engagement of the war, Virginia militia under 22-year-old Lieutenant Colonel George Washington defeat a French reconnaissance party in the Battle of Jumonville Glen in what is now Fayette County in southwestern Pennsylvania.
1863 – American Civil War: the 54th Massachusetts Volunteer Infantry, the first African American regiment, leaves Boston, Massachusetts, to fight for the Union.
1905 – Russo-Japanese War: the Battle of Tsushima ends with the destruction of the Russian Baltic Fleet by Admiral Togo Heihachiro and the Imperial Japanese Navy. The Japanese Navy grows fiercely overconfident from this victory, and the overconfidence contributes to their losses in WW II.
1937 – Neville Chamberlain becomes British Prime Minister. The Neville Chamberlain School of Diplomacy is highly regarded by the Left. “Peace in our time”, my a**!
1940 – World War II: Belgium surrenders to Germany to end the Battle of Belgium. In ancient tongues, “Belgium” translates to “Gateway to Paris”.
1964 – The Palestine Liberation Organization (PLO) is formed, because hating Jews needs a new letterhead.
1987 – 19-year-old West German pilot Mathias Rust evades Soviet Union air defenses and lands a private plane (stealth Cessna 172) in Red Square in Moscow. He is immediately detained and is not released until August 3, 1988. Several high (and low, no doubt) ranking officers are ‘disciplined’ in the Soviet military.
1996 – U.S. President Bill Clinton’s former business partners in the Whitewater land deal, James McDougal and Susan McDougal, and Arkansas Governor Jim Guy Tucker, are convicted of fraud. Bill and Hillary, however, are as pure as the driven snow (or some other four-letter word beginning with “s”)
2002 – NATO declares Russia a limited partner in the Western alliance. Bet you forgot that, huh?
Grrrrr!
Up at 0600, on the road at 0615, drive three hundred and fifty miles to help a guy swap out a circuit breaker that’s tripping entirely too often (and way under the trip setpoint) and when I get here, the spare breaker is not correct. My ‘two hours, spend the night, drive home in the morning’ job just turned into ‘spend the night, get the new breaker around noon, then replace it and THEN drive home’.
Ah, human frailties. Mistakes are made.
Today in History – May 27
1703 – Tsar Peter the Great founds the city of Saint Petersburg. Then it’s Leningrad. And now it’s Saint Petersburg again. In another five years it’s laible to be Putinopolis.
1919 – Charles Strite patents the pop-up toaster.
1919 – The US navy NC-4 aircraft arrives in Lisbon after completing the first transatlantic flight. Wasn’t even close to being non-stop, and two sister aircraft, NC-1 and NC-3 didn’t make it.
1941 – World War II: The German battleship Bismarck is sunk in the North Atlantic killing almost 2,100 men.
1995 – In Culpeper, Virginia, actor Christopher Reeve is paralyzed from the neck down after falling from his horse in a riding competition, becoming the Left’s favorite vegetable.
Food for Thought – 26 May 2014
