PLC Programming for 3 Motors control in Ladder logic

Write the PLC Programming Motors logic for the following problem.

There are three motors (M1, M2 & M3), having a separate start and stop push button.
M1 must be running before starting of M2 and M3 motor.
M2 and M3 can start and stop without affecting M1 operation.
Only two motors can run at the time. Starting of the third motor will shut down all the outputs immediately irrespective of its input.

PLC Programming Motors

Program Description:

Rung 0000:

Start/Stop PB latched with memory B3:0/0 for Motor 1.B3:0/3 is connected in series with latch memory to turn off all motors.

Rung 0001:

Start/Stop PB latched with memory B3:0/1 for Motor 2 .B3:0/0 is connected in series to turn on M2 only after M1.

Rung 0002:

Start/Stop PB latched with memory B3:0/2 for Motor 3 .B3:0/0 is connected in series to turn on M3 only after M1.

Rung 0003:

Turning on M1 when B3:0/0 turns ON

Rung 0004:

Turning on M2 when B3:0/1 turns ON

Rung 0005:

Turning on M3 when B3:0/2 turns ON

Rung 0006:

M2 and M3 outputs are connected in series to enable B3:0/3

Program Output:

When M1 turns ON,

When M1 & M2 turns ON

When the Third motor Turns ON,

Conclusion:

We can use this example to understand the programming logic in Allen Bradley PLC.

Comments

Ferrules and Cross Ferruling

Ferrules are identification labels provided for every wire terminations in an instrument, equipment, or electrical/instrumentation control panels. These tube-shaped sleeves can be inserted easily on each individual wire in a multi-core cable. In earlier days fixed digits/letters are used as ferrules, but now Instrumentation engineers/technicians prints out desired ferrules by using a ferrule printing machine. Typical Ferrule The numbers/ letters on the ferrules will be given as per the approved electrical hook up or loop diagrams. This helps technicians to easily identify a particular loop/wiring from a series of terminal blocks and to troubleshoot the desired terminal connection. Separate numbers on the ferrules distinguish the positive and negative polarities of wires, thus ensure the polarity protection of the instrument. Cross Ferruling As a wire is connected on its both ends, it is quite useful to use a cross reference method for wire identification. Unlike normal ferru...

What is a Torbar? – Averaging Pitot Tubes

The Torbar is employed for flow measurement of liquids, gases, or steam in circular, square, or rectangular section ducts for large flow rates. The Torbar is an insertion type multi-port self-averaging primary sensor for flow measurement. Torbar TORBAR is a set of Pitot tubes mounted on a bar across the pipeline with no moving parts. An averaging Pitot tube is a technology, while TORBAR is a manufacturing brand name. There are several brands available in the market with VERABAR, ANNUBAR, etc. Averaging Pitot Tube Principle Purpose Averaging Pitot tube can be employed when the average velocity of the flow profile, rather than the velocity in a specific point in the cross-section is desired. Averaging Pitot Tubes Principle It measures the differential pressure between the static pressure tap and the tap of full pressure of a stream. Thus such magnitude of differential pressure is directly proportional to the square of the flow rate. Working The TORBAR is designed in such a way that ...

Dissolved Oxygen Analyzer Working Principle

What is dissolved oxygen ? Dissolved oxygen refers to oxygen dissolved in water. Its concentration is expressed as the amount of oxygen per unit volume and the unit is mg/L. Biologically, oxygen is an essential element for respiration of underwater life and also acts as a chemical oxidizer. The solubility of oxygen in water is affected by water temperature, salinity, barometric pressure, etc. and decreases as water temperature rises. Measurement of dissolved oxygen by the membrane electrode method The membrane electrode method measures a diffusion current or reduction current generated by the concentration of dissolved oxygen or partial pressure of oxygen to obtain the concentration of dissolved oxygen. This method is not affected by the pH value of water being measured, oxidation and reduction substances, color, turbidity, etc. and the measurement method offers good reproducibility. When a sensor is inserted into water, an air layer forms on the membrane (Teflon membrane). The ox...

TILI Automation

Search This Blog