Problem Statement:
In industrial and automation environments, controlling devices
like fans manually
leads to:
Delay in operation
Human errors
Unnecessary power consumption
Hence, an automatic fan control
system using PLC is required
to ensure efficient and reliable operation.
Diagram: -
Objective:
To design a fan control system
using PLC ladder
logic
To implement Start/Stop control
with latching
To automate fan operation
using an object sensor
To ensure safe and efficient control without manual intervention
System Components:
Hardware Setup (Trainer Kit)
PLC (Schneider Control Expert)
Fan Control Module (PLI-08)
Push Buttons:
START (X0)
STOP (X1)
Object Sensor (X2)
Output:
FAN (Y0)
DC Power Supply (+24V)
Software Used:
PLC Programming Software: Eco Structure Control Expert
Working Principle:
Step-by-Step Operation
START Button Pressed (X0):
PLC energizes internal relay R1
System gets latched (self-holding)
STOP Button
Pressed (X1):
Breaks the
circuit
R1 de-energizes
Fan turns
OFF
Object Sensor
(X2):
Detects presence
of object/person
When R1 ON
+ Sensor ON → Fan ON
Fan Operation:
Fan runs only
when system is on and object is detected
PLC Diagram:
PLC Ladder Logic
Explanation:
Rung 1: Start/Stop with Latching
START (NO) → STOP (NC) → Coil R1
Parallel contact of R1 → provides
latching
Function: Keeps system ON even after releasing START
Rung 2: Fan Control
R1 (NO) → Object Sensor (NO) → FAN
(Y0)
Function:
Fan runs only when:
System is ON
Object is detected
Advantages
Simple and reliable operation
Energy efficient (fan runs only when needed)
Easy to modify PLC logic
Reduces human intervention
Suitable for industrial automation
Applications
Automatic ventilation systems
Industrial cooling systems
Smart rooms and buildings
Conveyor-based systems (object detection)
Conclusion
The PLC-based fan
control system provides an efficient
and automated
solution for controlling fan operation.
Using Start/Stop
logic w ith
sensor-based control, the system ensures energy saving and reliable performance. This project demonstrates the practical implementat ion of PLC
in real-world automation systems.