ELECTRICAL CONTROL PANELS -An interesting perspective ( part 1)

Hello again,

This title must confuse you especially after my first philosophical post (not a big fan of philosophy),but the first post was important for understanding my purpose for writing.This is the first step that i am taking towards educational redemption.

First a little Disclaimer: "I am not an expert or something,i am a student who is trying to share his whatever little knowledge he has with you people.I  may be wrong sometimes,so if i am at any point feel free to comment on it".

The topic that i have chosen is "Control Panels".I basically am an electrical engineer and this interests me so,lets give it a try.The method i am talking about is about asking more and more questions,from something you read or imagine (even better).The first step would be to see it from a visual perspective.Let's take an example picture.
So,what do we see here?. Let's make a firsthand raw impression.

• I see a metallic box in which there are switches,lots of wires,channels on which the components are mounted,switches,circuit breakers,terminal blocks etc.
  

Let's see another picture...

And another one...(they say pictures are the best form of learning )

A big panel..

Let's talk about the various components that we can understand that should be a part of a control panel

1. A metallic box
2. A PCB or panel for mounting .
3. Switches
4. Switch-gear(circuit breakers,relays,fuses etc.)
5. A A.C to D.C converter for the electronics(mostly up to 24 V).
6. Batteries or something(for backup maybe,NOT SURE!)
7. Terminal blocks (for wires termination).
8. Rails on which all the components are mounted.
9. Temperature controller (as control panels are enclosed,so i suppose temperature control becomes necessary).
10. A display (obviously!!).
11. A computer(here it is a PLC to control all these guys).
12. A lot more things i suppose, but these were just firsthand visual observations.
    

First of all let's make some questions for some of the parts...

• What kind of metallic box are used ?why,can't we keep them in open?What kind of protection is it supposed to provide?What standard does it comply to?
• What kind of PCB or panels are used ?Why?
• What kind of switches are used?
  

Let me me interrupt you here,before all this things just sit back and imagine that you want to control something (like something electrical of course) let's take a D.C motor.Now mind you that there is a basic difference between running and controlling.We could plug the motor directly to the supply and it would start running,but alas! controlling it ain't that easy .Now the key to controlling a D.C motor basically is that you need to control it :

• By varying the supply voltage
  
• By varying the flux, and by varying the current through field winding
  
• By varying the armature voltage, and by varying the armature resistance
  

Again this is just the listing of technicalities(so don't ask “how or why?”) our main goal here is to have a rough idea about the components in a control panel.This post is just the part of pre learning experience about control panels.

In the next post we are gonna go into much more detail about the introduction to control panels and also i will be posting the answers to those questions in this post.Also a bunch of new questions are on the way,so stay tuned!!

So long guys!!

Until the next time..

Keep asking why???.

Cheers!.