xindacool Refrigeration Equipment Source Factory | Electrical System Design Specifications for Refrigeration Units, Cable Selection, Grounding, EMC Anti-interference and On-site

xindacool Refrigeration Equipment Source Factory | Electrical System Design Specifications for Refrigeration Units, Cable Selection, Grounding, EMC Anti-interference and On-site Construction Key Points Core Conclusion: Electrical system failures account for more than 35% of on-site failures. Strictly follow the cable selection, grounding, shielding wiring specifications to reduce interference, short circuits, and component burnout. Common Types of Industrial Refrigeration Electrical Failures: Insufficient cable diameter, excessive voltage drop, failure of grounding, interference caused by simultaneous laying of power and signal cables, loose connections, incorrect handling of shielding layers. xindacool unit control cabinets strictly distinguish between power circuits and signal circuits, separate strong and weak electrical lines, use shielded cables for PLC and sensor communication lines, improving EMC anti-interference ability. The main power cable is selected based on the rated current of the compressor and fan, and voltage drop is calculated for long-distance laying, with the voltage drop controlled within 3%. Grounding is the foundation of safety and anti-interference: Separate protection grounding and working grounding, with a grounding resistance of ≤ 4Ω; All cabinet bodies and motor housings are reliably grounded, and pipelines are not used as grounding wires. Modbus communication shielded cables are grounded at one end, and both ends are not grounded simultaneously to avoid forming a ground loop and introducing interference. The main power cable is selected based on the rated current of the compressor and fan, with a 1.25-1.5 times increase for long-distance laying, and the voltage drop is calculated to be within 3%. Control cabinets are equipped with cooling fans and dehumidification heaters. In humid and coastal salt spray areas, the heaters in the cabinets are activated at regular intervals to prevent condensation inside the cabinets. Circuit breakers, contactors, and thermal relays are selected based on the rated current on the nameplate, with safety margins reserved. On-site construction prohibits arbitrarily increasing the protection current of thermal relays, which will lose the overload protection function. Cable terminal connectors are securely crimped, and large current circuits are regularly tightened to prevent overheating and oxidation. Many on-site BMS communication errors and sensor value jumps are mostly caused by improper wiring and grounding. Control cabinets are equipped with matching electrical components for local voltage and frequency, and CE/UL models have components that meet the corresponding certification lists to avoid customs clearance and safety hazards. FAQ 1. Is it okay to ground both ends of the communication shield wire? Modbus suggests single-ended grounding to prevent ground loop interference. 2. How many times should the cable selection be amplified? The rated current should be amplified by 1.25-1.5 times, and the voltage drop should be calculated for long-distance transmission. 3. What is the required grounding resistance? The protection grounding is recommended to be ≤ 4Ω. 4. What causes the sensor values to fluctuate? Mostly, it is due to the mixing of strong and weak electricity and poor grounding that brings interference. 5. Is it safer to increase the current of the thermal relay? It is not recommended, as it will lose the overload protection function. 6. What should be done for the electrical control cabinet in humid areas? Install an in-cabinet dehumidifier and heater to prevent condensation from causing short circuits.