Wiring Diagram Flashcards
(31 cards)
We have a tage attached to the cable of the motor with M142(one frothy two) mentioned on it.
ETC: Et cetera
و غيره
Now the question here is that where this cable is connected in the machine electrical panel,and how dose the PLC controling tis motor.
If we see the sheet of the electrical wiring diagram,every sheet has a unique number mentioned on the right bottom corner of the page
The next thing you can see at the top of the sheet,this sheet is divided into some vertical colums,starting from column numbers 0 all the way up to column number nine.
If you see the left side of the sheet it is divided in some horizontal rows starting from a,b,c and up to f.this rows and columns together make a grid on the sheet.this grid makes it easier to locate objects on this sheet
So before going into electrical wiring diagram,we should know the basic symbols of the electrical devices like push bottoms,contactors,power supply and ETC.
In the all of the drawing there will be few sheets showing all the items and the devices used in the project along with their symbols.
We will see now how can trace back the wiring of this motor.
How we can find out this motor on this electrical diagram that consists of several page.
As you can see this motor is a three phasemotor and it’s wires are connected to the terminalstrip.inside the electrical panel,you can see that the three wires U142,V142,W142 are connected at u ,v,w output terminals of the VFD,so this motor M142 is driven by omron VFD and VFD tag is xx
If you look at the top of the sheet,here you will see three lines,this three lines are the symbols for the three phase power supply,from here the three power fed into the QF142 breaker
VFDs notmally requires a run command signal from the PLC to turn on the motor .
This terminal receives a run command signal from PLC ,if you see closely this signal is coming from the normal open contact of the relay KA369
To find out this relay we have to see the first two digits of the tag KA369
This is theKA369 symbol for this relay coil,it look like a rectangular box.
You can see that one end of the coil is connected to the zero volts line.and other end of the coil is connected to the number seven terminal of the PLC output card,number 7 terminal is the A05 output of the PLC,and it is mentioned here as glue pump start command.
FR andFC arethe analog input of the VFD,if you see the drawing ,these two wires have tag 5210,and 5211 and this wires or lines have an arrow symbol at the starting point ,52.2 is mentioned near to these arrows.what does this mean?this mean that these wires are coming from the sheet 52
From these terminal block, we move on to a three pole circuit breaker with thermal and short circuit protection capability.
After closing this circuit breaker manually, the power flows toward some power distributer bars,from which some branches can be taken.
One of the branches goes into a two-pole circuit breaker
Wire tages are the combination of some letters and numbers installed on the wire or cable and are used to show you to wich device or terminal block a wire or a cable should be connected.
مي توانيد به راحتي به نمودار سيم كشي نگاه كنيد و بفهميد كه كجا بايد دوباره وصل شود.
For instance, the main three-phase power is shown with some arrows and numbers on the top right-hand side of the page.
به عنوان مثال، برق سه فاز اصلی با تعدادی فلش و اعداد در سمت راست بالای صفحه نشان داده شده است.
And how do I know that?! If you have seen the legend and abbreviation page of the drawing you know that the “-KA” is a nomenclature for a relay in this drawing.
nomenclature: نامگذاري
