# Can anyone suggest a good book



## Wirenuting (Sep 12, 2010)

jza said:


> Motor control for beginners... Something that would go into depth on AC motor control.


Electrical motor controls by Gary Rockis..
Mine is the 97 version book with instructor guide. 
The Square D wiring hand book. 
You can download that from them as a PDF for free. 
Refrigeration & air conditioning technology by William C Whitman
Mine is the 3rd edition
A Farewell to Arms
By Hemingway
Cause it's just a good book


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## Rudeboy (Oct 6, 2009)

My library has _understanding motor controls_

I'm far from an expert but it seems pretty good and includes a dvd.


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## jza (Oct 31, 2009)

Will these things talk about VFD's, starters, interlocks, overloads, etc.?


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## Rudeboy (Oct 6, 2009)

It was awhile ago but it had some stuff on PLCs. 
So yeah i think so.


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## miller_elex (Jan 25, 2008)

jza said:


> interlocks,


Ahh... the most important thing..... and the least spoken about!

These are how the controls fakers get weeded out IMO.


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## Wirenuting (Sep 12, 2010)

jza said:


> Will these things talk about VFD's, starters, interlocks, overloads, etc.?


They will to some extent. The Square D wiring book just shows how to wire, no explanations. 
The other 2 show & explain controls and interlocks. 
The best VFD books I've seen are the install, start-up and operating manuals that come with each unit. Most of them are downloadable PDF files. 
Look at a book store before buying. Ask your local library to ship in a copy for you to read. Check out your local college book store. There is a store called constructionbookstore.com They have a nice rounded selection. 

The hemmingway book is just good reading. Nothing to do with work.


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## rlc3854 (Dec 30, 2007)

miller_elex said:


> Ahh... the most important thing..... and the least spoken about!
> 
> These are how the controls fakers get weeded out IMO.


So true! Several years ago (28) I worked at a prison that had a huge rotary oven that had controls for switching from a delta to star start-up and reversing contactor. From what I remember this was for torque control/speed. This contactor also controlled door locks, gas control, fans both exhaust and circulating. There were four of us just staring at it until the smart one says ok I see how it works and I see the problem and proceeds to troubleshoot and repaired the thing. The biggest thing was the interlocks and switching for trouble shooting just like boilers everything is about safety.


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## John Valdes (May 17, 2007)

miller_elex said:


> Ahh... the most important thing..... and the least spoken about!
> 
> These are how the controls fakers get weeded out IMO.


And just how do "interlocks" "the most important thing" weed out the fake control guys? I am asking and I am not trying to be a smart ass either.


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## millelec (Nov 20, 2010)

w/me, learned how Low Voltage Release, Low Voltage Protection, and Low Voltage Protection Automatic control setups worked. once you learn those basic controller types and how they work, all the interlocks/controls add-ons can be figured out. helps to have a good schematic too!


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## miller_elex (Jan 25, 2008)

John Valdes said:


> And just how do "interlocks" "the most important thing" weed out the fake control guys? I am asking and I am not trying to be a smart ass either.


 
Let's see..... dead heading pumps, warped dampers, all very expensive to repair when interlocks aren't done right. 

Shall I go on????????


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## PsiMan84 (Oct 29, 2010)

i've seen people replace contactors, timers, and many other things when all it was just an interlock switch that was bad. I do believe like the other poster said it does weed out fakers when it comes to troubleshooting in the field.


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## Thedroid (Dec 6, 2010)

9 times out of 10 machine troubleshooting comes down to interlocks. It really comes down to being good with schematics, and following a plan with your troubleshooting. If your going to be doing a lot of troubleshooting, get yourself a good book that shows all of the different types of switches, pressure, temp, limit, etc, and study all of them. This will pay off later.

I work in a cement plant that has hundreds of interlocks. One section of the plant has not been automated and still uses 480V control. Each MCC has a relay section with hundreds of interlocks, and all of the motor starters have several aux contacts involved. These machines also span 5 floors with the MCC's in the basement. Even the best electricians have no chance without the prints, patience, a plan, and how could I forget jumpers.


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## Jlarson (Jun 28, 2009)

Oh come on, it's not rocket science. Seriously how hard is it to figure out a limit, temp, pressure, flow switch or any other type of switch? If you can think even halfway logically, read and follow lines and work a multimeter you can get the hang of controls.


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## Wirenuting (Sep 12, 2010)

Jlarson said:


> Oh come on, it's not rocket science. Seriously how hard is it to figure out a limit, temp, pressure, flow switch or any other type of switch? If you can think even halfway logically, read and follow lines and work a multimeter you can get the hang of controls.


Ask some of the goofballs I work with. They don't know what logic is. Power to the starter and then they walk away.


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## eric7379 (Jan 5, 2010)

Jlarson said:


> Oh come on, it's not rocket science. Seriously how hard is it to figure out a limit, temp, pressure, flow switch or any other type of switch? If you can think even halfway logically, read and follow lines and work a multimeter you can get the hang of controls.


:thumbup: How true it is!


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## eric7379 (Jan 5, 2010)

PsiMan84 said:


> i've seen people replace contactors, timers, and many other things when all it was just an interlock switch that was bad. I do believe like the other poster said it does weed out fakers when it comes to troubleshooting in the field.


People that follow this practice are not technicians at all. They are merely parts-changers and have absolutely no clue at all about how to effectively troubleshoot. This is my biggest pet peeve.


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## Thedroid (Dec 6, 2010)

Jlarson said:


> Oh come on, it's not rocket science. Seriously how hard is it to figure out a limit, temp, pressure, flow switch or any other type of switch?


The switches are very easy to figure out. Any electrician should fully grasp the concept of them wether they work with them or not. It can get tricky though. I worked with a plastic blowmolding machine that had 30 different 8 pole relays that was very tricky to troubleshoot. If you weren't familiar with the machine it was especially tough.

The system I described in my 1st po st is another complicated one. 480 control fully interlocked machine consisting of 100 different motors ranging from 3 to 150hp and spread out over 5 floors. We have all types of devices and safeties to make sure nothing gets buried or broken. The prints are 50yrs old, and the controls have been worked on by 50yrs worth of different electricians. You have to have a systematic approach to finding problems, or you'll have some bad days.

IMHO modern PLC controlled machines are far easier to troubleshoot than the old relay logic, and imho does seperate the men from the boys.


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## Jlarson (Jun 28, 2009)

Even PLC stuff isn't that hard, as long as you are good with computers on top of having a good understanding of hardwired controls you can learn it and be good at it with no real problems. 


Possibly the hardest part of controls (at least for some people) isn't understanding the electrical side or the programming it's understanding the process/mechanical side of things.


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## miller_elex (Jan 25, 2008)

Jlarson said:


> as long as you are good with computers on top of having a good understanding of hardwired controls you can learn it and be good at it with no real problems..


 
Ummm, thank you Mr. Electronic Degree. Most electricians think of a circuit as a power source, ocpd, conductor, and a load. Even then yet again, some are considered lucky to be good pipe benders. What seems easy for you doesn't translate well to many. IMO. Most electricians have no idea what happens in a built up air handler.


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## Jlarson (Jun 28, 2009)

miller_elex said:


> Ummm, thank you Mr. Electronic Degree.


:laughing::no: No electronic degree here



miller_elex said:


> Most electricians have no idea what happens in a built up air handler.


That's why I made the process/mechanical side comment


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## Hunter1151 (Nov 4, 2010)

Jlarson said:


> Even PLC stuff isn't that hard, as long as you are good with computers on top of having a good understanding of hardwired controls you can learn it and be good at it with no real problems.
> 
> Possibly the hardest part of controls (at least for some people) isn't understanding the electrical side or the programming it's understanding the process/mechanical side of things.


This is so true, when something fails, why is it always electrical, I was on a service call where they said there plc needed adjusted because the encoder was not reading right, it has been in operation for years, the one product was only 17" wide, this was the only one that the encoder was reading wrong.. When I looked at the machine the rubber coating on the pinch roll was warn about 20" area, they decided getting the roll redone was not the fix, but move the encoder and rewrite the software was... Kind of off subject, to be a good tech, you need to have common since, patience and an understanding of the machine's sequence of operation, be ably to read and understand the drawings. If needed manuals for hardware, if it is service, most likely the drive or plc has been running for sometime, so usually unless they fail, the are not the issue. Look for stripped wires and jumpers where some dumb ass tried to bypass something.


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