Daisy Chain

747

Daisy Chain
When conductors run from one device to the next. Saves wire, but if one device fails, all downstream devices are affected.

I bet MD didn't know that.

MSSI

Not necessarialy true..If you have something wired in series and there is a break in the chain then yes. If its wired in parrellel like lights or recepts. it wont affect anything downstream unless the wires themselves get seperated from one another. a recept. would have to get pretty fried for that to happen. Usually the outlet will cook without the termination points being extremely affected.

jmic

FWIW I agree.

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Joe

thom

747 other than some christmas tree light strings, what is wired in series? No one wires buildings that way. So what exactly is your point?

One more thing 747, MD's a smart guy, I'm certain he knows about and understands series wiring. It just seems you're not smart enought to see how knowledgeable MD is.

DAVIS081404

Anybaody thinking about challenging MD's knowledge should reconsider.Take a look through just about every post he has made. Ive learned a lot from his input.

reveivl

747 has been here forever and probably read every post written and all of MD's. I think he was being facetious (joking). What the point of his post is I don't know, but I'm sure he meant no disrespect to anyone.

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From where does knowledge come? If you need to know what is in a box, you could ask someone (not reliable), you could pray, (not useful), you can consult with the scripture (not helpful) or you could open the box (science)

mickeyco

Your see series wiring all over the place, limit switches on furnaces and AC units, most every company that has battery back-up, has a battery bank wired in series and there are plenty of situations, for safety where you will see series wiring. I'm not trying to make any points here or question anybody's qualifications, just point out that there are plenty of areas (many more then I've listed) aside from x-mas lights that use series wiring. And I also believe that mdshunk is aware of all of this, if I had an electrical question I needed answered he's the guy I'd ask.

Sparky Joe

I'm sure he knows how knowledgeable MD is, looked to me like a joke on such a silly question.

Oh and fire alarms and security systems are wired in series, so that the fire or security panel know when a device has failed and can signal a trouble alarm so it can be fixed.


Ever heard of "and" logic(just learned that in school and was wondering when I could apply it)

mdshunk

Good to see you guys got my back.

I know that 747 was just goofing around with that statement. He's a 747 pilot, after all, and not an electrician. He's the official airline pilot of ContractorTalk, so we keep him around.

747

I was just goofing with MD.

thom

747, What's with the measure twice cut once? Can't you measure correctly the first time?

DAVIS081404

Logic is good stuf to know. I was involved with some substation relay changeouts and every single action is a result of logic. We were taking rooms full of electro mechanics and condensing it into a single box. It was a very interesting job. A guy can make an excellent living if he understands logic.Take all the classes they will give you.

mdshunk

Agreed. The logic, and the "programming" that will follow, will help you tremendously if you get into the PLC end of the electrical trade. Relay logic is pretty much past tense, being quickly replaced by PLC's, but there's still enough relay logic installations around to make a good relay logic troubleshooter a guy that is well paid.

Sparky Joe

They say this semester is hardest of all, and I'm only 1/3 the way through. I did pretty well on the logic test, I think I could still draw a circuit showing the functionality of all the gates.

Anyone know what logic a 3-way switch is? You use them every day....

PLC's are coming up and they haven't even primed us yet, but the teacher I have for this year knows electronics like no one else I've met(kinda funny because he's a big barrelling, burly guy. Wouldn't think of him as knowing this stuff). He says we gotta write a "jeopardy" program for the PLC cabinet to understand, he pointed out several times that when one button is pushed the other buttons(to signify an answer) are locked out. So it seems he thinks the "interlocks" will be the hardest part.

He's really a sharp guy, has drawn the schematics for nearly every electronic device we use from memory which really helps to see how these(electronic device) things work. and he really loves the VFD's which revolutionized our industry in the past few years.

mdshunk

SparkyJoe.... The "Jeopardy" answer button and a traffic signals for an intersection are the textbook PLC problems for students. Start researching these now. Traffic signal is harder.

747

Just for clarification. I think the 747 is the best big old girl in the sky. The majority of pilots agree. However i fly for American and we don't have the 747 in our fleet. The plane you will find me in the majority of the time will be either the boeing 757 or boeing MD-80. The only two U.S. carriers who still have the 747 in there fleet are United with the most and i think Northwest has a couple. International carriers i know japan airlines has a couple.

Ps. The original post was just to see if MD was still alive and kicking up on the east coast.

Sparky Joe

The "boeing" MD-80 huh? doesn't the MD stand for McDonnell Douglas?
My Dad worked for MD on the C-17 project until they folded.

I've been working in this corporate jet hanger for the past week. They have a pair of gulfstream G-5's(though the plane says G-550), a French made "falcon" which is a 3 engine jet that they swear is a tank compared to a twin engine American made jet of the same size, don't know the maker, but they say it's the fastest corporate jet ever made at Mach 0.93(because Mach 1 is illegal).

Just wanted some input from a pilot, I never get to talk to them while they're there(in and out in 2 minutes), so I have some ammo against the guy feeding me all this crap(the general's foreman).

Thanks, Joe

747

Yes MD stands for mcdonald douglas. But they merged in 97 or 98 with Boeing. For you other question. Yes mach 1 or equal to the speed of sound is illegal because once you break the speed of sound the boom with break windows on the ground. Mach 0.93 is just 93 percent of the speed of sound. I cant answer if that is the fastest coperate jet because i don't know to much about coperate jets. On one hand that is fast on the other its not. Example the 757 wide open will do mach 0.80. Compare the size of that to a little coperate jet. Sounds to me like your working in a maintance hanger. Those guys are engine fantatics. Sorry i cant give you some firing back power i honestly don't know to much about the little coperate jets. Nore to i really care because i won't ever fly coperate. I would of stayed in the USAF before flying coperate.

Sparky Joe

Interesting, why is that? The corporate pilots seem to do alright..... other than being on call 24/7.

I don't when Douglas went under exactly, but it was '94 when my Dad was laid off and we moved to Oregon to work for Pac.Corp. That really sucked

747

I never said corporate pilots don't make a decent living. Its just the 24/7 lifestyle that doesn't appeal to me. To answer your question. Long range flying speed is 0.80 maxed out at 0.87 I don't know where they get the 0.93 at for a 550 gulfstream. Which is a pretty impressive plane. Maxium flying distance on a tank of gas is around 6500 Nautical miles that is also pretty good. Maxium climb is 51,000 which also isn't bad. Actually I was kind of impressed reading the specs on it. Although i have never flown one it does look good on paper. That is fast for that kind of plane. Most small jets like that are around 0.60-0.70 in speed. Its also has a royals royce engine we like that.

Ps. Concerning mach 1 being illegal. If you were to go mach 1 over land the sonic boom would shatter windows in stores. I'm not sure about residental but big windows would crack.