Perancangan Sistem Otomatisasi Air Handling Unit Berbasis PLC dan HMI

Abstrak

Sistem Air Handling Unit (AHU) merupakan komponen utama dalam pengaturan kualitas udara di dalam ruangan. Penelitian ini bertujuan untuk merancang sistem otomatisasi AHU berbasis PLC Mitsubishi MELSEC iQ-R dan HMI GOT2000 yang mampu beroperasi dalam dua mode, yaitu otomatis dan manual. Perancangan dilakukan menggunakan perangkat lunak GX Works3 dengan metode Function Block Diagram (FBD), dan HMI dikembangkan dengan GT Designer3.
Sistem ini menerima input berupa sensor suhu, kelembapan, CO₂, dan sinyal digital dari Differential Pressure Switch (DPS) sebagai indikasi filter kotor. Output sistem berupa kendali motor fan AHU dan Motorized Control Damper (MCD), serta tampilan status dan alarm di HMI. Pengujian dilakukan dalam bentuk simulasi untuk memverifikasi logika program, akurasi konversi input analog, dan integrasi komunikasi antara PLC dan HMI.
Hasil pengujian menunjukkan bahwa sistem dapat menjalankan urutan kontrol sesuai skenario yang dirancang. Konversi data sensor analog berhasil ditampilkan dengan akurat, dan fungsi alarm bekerja sesuai kondisi simulasi. Sistem ini dapat menjadi model dasar dalam pengembangan sistem kontrol HVAC otomatis berbasis PLC.
Kata kunci : AHU, PLC Mitsubishi, GX Works3, sensor suhu, sensor kelembapan, HMI GOT2000

Abstract
The Air Handling Unit (AHU) is a core component in controlling indoor air quality. This study aims to design an automated AHU system based on Mitsubishi MELSEC iQ-R PLC and GOT2000 HMI, capable of operating in two modes: automatic and manual. The system is developed using GX Works3 software with Function Block Diagram (FBD) method, and the HMI is built using GT Designer3.
The system receives input from temperature, humidity, and CO₂ sensors, as well as a digital signal from the Differential Pressure Switch (DPS) to indicate dirty filters. The output includes control of the AHU fan motor and Motorized Control Damper (MCD), along with real-time status and alarms displayed on the HMI. The program was tested through simulation to verify control logic, analog input conversion accuracy, and communication between PLC and HMI.
The simulation results show that the system can execute control sequences as intended. Sensor data was accurately converted and displayed, and alarm functions responded appropriately to simulated conditions. This system can serve as a reference model for the development of automated HVAC control systems using PLC.
Keywords: AHU, Mitsubishi PLC, GX Works3, temperature sensor, humidity sensor, GOT2000 HMI