Mechanical · Energy and thermal · Final year project
PLC Based Multi-channel Fire Detection & Alarm System
A PLC fire alarm that monitors flame detectors on several floors. Any detector that senses fire triggers audio and visual alarms and shows the location.
What is the PLC Based Multi-channel Fire Detection & Alarm System project?
A PLC fire alarm that monitors flame detectors on several floors. Any detector that senses fire triggers audio and visual alarms and shows the location.
Key facts
- Branch
- Mechanical & Automobile Engineering; also suits Mechatronics, Instrumentation
- Type
- Final year project · Advanced
- Suitable for
- Diploma capstone and B.E / B.Tech final year
- Build time
- 6 to 8 weeks
- Estimated component cost
- ₹14,100 – ₹20,800
- Guidance from
- ₹9,999 (Hardware / IoT Final Year)
How the PLC Based Multi-channel Fire Detection & Alarm System works
- The mild steel frame and fabrication forms the base that carries every other part, so it is designed first from the load and size of the machine.
- The DC geared motor provides the driving motion.
- Motion is transmitted through DC geared motor, which set the speed, torque and direction at the working end.
- The Compact PLC runs the ladder logic that sequences the machine's inputs and outputs, the way industry automates processes.
- The Gas / smoke sensor detects LPG, smoke and flammable gas leaks.
- The Push buttons and switches provide manual inputs and the power switch.
Block diagram
Power
DC geared motorMini submersible water pumpRelay moduleTransmission
DC geared motorStructure
Frame and mountsComponents list and cost
Typical prices from Indian online stores and electronics markets (Lamington Road, Budhwar Peth, SP Road). Buy from one store where you can to save on shipping.
| Component | Qty | What it does | Approx. cost |
|---|---|---|---|
| Compact PLC (e.g. Delta DVP / Siemens LOGO!) | 1 | Runs the ladder logic that sequences the machine's inputs and outputs, the way industry automates processes. | ₹9,500 |
| Gas / smoke sensor (MQ-2) | 1 | Detects LPG, smoke and flammable gas leaks. | ₹120 |
| Push buttons and switches | 1 | Provide manual inputs and the power switch. | ₹40 |
| DC geared motor | 1 | Provides the driving motion. | ₹250 |
| Mini submersible water pump (12 V) | 1 | Moves water for irrigation, dispensing or cooling. | ₹180 |
| Relay module | 1 | Switches mains or high-current loads such as lamps, pumps and fans from a low-voltage signal. | ₹70 |
| LEDs (assorted) | 1 | Indicate status. | ₹20 |
| Buzzer | 1 | Gives an audible alert. | ₹20 |
| Mild steel frame and fabrication | 1 | Forms the main structure that holds all parts. | ₹2,500 |
| Welding, cutting and machining labour | 1 | Needed for this type of build. | ₹2,200 |
| Door | 1 | Part from the design specification | ₹400* |
| Mounts, screws, nuts and small hardware | 1 | Enclosure, mounts and fasteners. | ₹300 |
| Paint, finishing and workshop consumables | 1 | Project overhead | ₹600 |
| Transport of material | 1 | Project overhead | ₹400 |
| Estimated total | Varies with brand, quality and city | ₹14,100 – ₹20,800 |
Prices are estimates for budgeting; items marked * depend on the exact size or model chosen. We confirm the bill of materials when your design is frozen, and components are charged at actual cost with bills.
How much does this project cost?
| Option | What you get | Cost |
|---|---|---|
| Components only | You buy the parts and build it yourself | ₹14,100 – ₹20,800 |
| Hardware / IoT Final Year | Working model or guided build, Circuit diagram and bill of materials, Firmware / code with explanation | from ₹9,999 + components |
| Capstone Project (CPE) | Working project or model, Black book in MSBTE format, Step-by-step explanation | ₹9,999 + components |
| Diploma ITR | 100% working source code, Project report PDF, PPT | ₹1,999 + components |
No GST and no hidden charges. Use the cost calculator for a quote with your deadline and add-ons, or see all plans.
Download the project brief (PDF)
Summary, working, components and cost and viva questions on one branded PDF to show your guide or team. To get it developed, contact us on WhatsApp.
What you submit with this project
- Working model with circuit diagram and program code
- Project report or black book in your university's chapter order (block diagram, circuit, calculations, results)
- Presentation for the review and final viva
- Synopsis for topic approval, if your college asks for one
Mechanical viva questions on this project
What is the aim of the PLC Based Multi-channel Fire Detection & Alarm System project?
A PLC fire alarm that monitors flame detectors on several floors. Any detector that senses fire triggers audio and visual alarms and shows the location.
Explain the working of your project in short.
The mild steel frame and fabrication forms the base that carries every other part, so it is designed first from the load and size of the machine. The DC geared motor provides the driving motion. Motion is transmitted through DC geared motor, which set the speed, torque and direction at the working end. The Compact PLC runs the ladder logic that sequences the machine's inputs and outputs, the way industry automates processes.
Why is a PLC preferred over a microcontroller in industry?
A PLC is rugged, works on 24 V industrial signals, tolerates noise and heat, and is programmed in ladder logic that maintenance staff understand. It is also easy to modify on site.
What is the principle of the MQ-2 gas sensor?
It has a tin dioxide (SnO2) layer heated by a small coil. When combustible gas is present, the layer's resistance falls, which raises the output voltage the controller reads.
Why is a pull-up resistor needed with a push button?
Without it the input pin floats and reads random values. The pull-up keeps it HIGH until the button connects it to ground.
Why is a geared motor used?
The gearbox reduces speed and multiplies torque, so a small DC motor can move a vehicle or mechanism smoothly. Torque increases roughly by the gear ratio.
How is the pump switched by the controller?
Through a relay or MOSFET, because the pump runs at 12 V and draws more current than the controller pin can provide.
Which material did you select for the main parts and why?
Mild steel (MS) is used for the frame because it is strong, cheap, easy to cut and weld and available everywhere. Shafts are made of EN8 or bright mild steel for strength, and parts that do not carry load can be aluminium or acrylic to reduce weight.
What factor of safety did you take in your design?
A factor of safety of 2 to 3 is taken for static parts and 3 to 5 for parts under shock or fatigue loading. Allowable stress = yield strength ÷ factor of safety, and each part is checked against it.
How did you estimate the cost of the project?
The cost is the sum of raw material, bought-out parts, machining or fabrication and overheads. Our estimate for this model is about ₹14,100 to ₹20,800, depending on size, material and the workshop rates in your city.
Which manufacturing processes were used?
Cutting and grinding of sections, arc or MIG welding of the frame, drilling for mounting holes, turning of the shafts and fitting of bearings and the drive, followed by assembly, alignment and painting.
Is your system open-loop or closed-loop?
Closed-loop: sensors measure the actual position, distance or condition and the controller corrects the actuators until the target is reached.
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Want to build PLC Based Multi-channel Fire Detection & Alarm System?
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