Views: 0 Author: Site Editor Publish Time: 2026-10-09 Origin: Site
With the continuous advancement of smart water services, industrial control cabinets serve as the control core of sewage treatment systems. They manage bar screens, lift pumps, aeration blowers, dosing units and sludge treatment equipment, performing logic control, water quality data collection, fault alarming and remote data uploading. Sewage workshops feature persistent high humidity, corrosive gases such as hydrogen sulfide, drastic temperature fluctuations and obvious vibration. Many projects suffer from component corrosion, condensation short circuits inside cabinets, communication interruptions and frequent equipment shutdowns due to improper selection of control cabinets. As an enterprise specializing in complete industrial electrical control systems, Shiyou Electric has summarized a selection scheme for sewage plant control cabinets based on project experience in municipal sewage, industrial wastewater, integrated sewage stations and lift pumping stations, helping engineering parties avoid selection risks and ensure stable operation of sewage systems.
Step 1: Determine cabinet protection standards according to on-site working conditions
Environmental conditions vary greatly across different zones in sewage plants. Pump rooms, bar screen rooms, dosing rooms and outdoor pumping stations have distinct requirements for anti-corrosion and protection ratings; ordinary industrial control cabinet standards cannot be directly applied. For conventional indoor sewage power distribution rooms, cabinets shall reach a minimum protection rating of IP54 and adopt thickened cold-rolled steel sheets with electrostatic powder spraying. For highly corrosive areas such as bar screen rooms and dosing rooms, 304 stainless steel cabinets are preferred. For outdoor pumping stations and industrial wastewater projects, upgrade to 316L stainless steel with a protection rating of IP55–IP66, equipped with sealed cable glands and elevated bases to block accumulated water and moisture. Cabinets are pre-fitted with temperature and humidity heaters to suppress condensation. High-power frequency conversion control cabinets may require industrial air conditioners when necessary to prevent corrosive gases from eroding circuit boards.
Step 2: Select proper hardware and control logic matching sewage treatment processes
Besides basic components including PLCs, frequency converters, circuit breakers and contactors, hardware configuration of sewage control cabinets shall adapt to on-site instrument collection and process control requirements. Compact PLCs such as Siemens S7-1200 and Inovance H3U can be adopted for small and medium-sized township sewage stations to realize pump rotation and simple PID regulation. Modular high-performance PLCs paired with distributed remote I/O are selected for large municipal sewage plants to connect a large number of field instruments.
The system collects 4-20mA analog signals of liquid level, dissolved oxygen (DO), pH, turbidity and sludge concentration to automatically adjust blower aeration, dosing pump flow rate and start-stop of lift pumps. Pump groups support one duty, one standby configuration, automatic fault switching and dry-run protection. Blowers adopt PID closed-loop speed regulation based on dissolved oxygen for energy-saving aeration. Bar screens start or stop automatically according to liquid level difference or time schedule settings, and dosing systems adjust metering pumps dynamically following water quality changes. Separate cable trunking for power cables and signal cables inside cabinets reduces electromagnetic interference caused by frequency converters. A 20% margin is reserved for I/O points to facilitate later reconstruction. For highly corrosive environments, PLC modules can be applied with conformal coating to improve circuit board corrosion resistance. Many equipment failures stem from insufficient spare points and inadequate electromagnetic isolation, forcing full cabinet replacement and resulting in economic losses.
Step 3: Plan smart water services and reserve communication and intelligent expansion capacity
Most current sewage projects need to connect with plant SCADA systems, online environmental monitoring platforms and some smart water platforms to realize remote monitoring, data storage and alarm push. Control cabinets shall support mainstream protocols such as Modbus-RTU, Modbus-TCP, with Profinet available as an option. Optional 4G/5G DTU edge gateways enable remote data uploading and debugging. For projects connected to online environmental monitoring, data interfaces are reserved before delivery to reduce secondary on-site modification. Equipped with local touch screens, the cabinets support fault recording and historical operation data storage to facilitate troubleshooting for maintenance personnel. Shiyou Electric’s sewage control cabinets reserve interfaces for smart water service upgrades, allowing platform connection without large-scale hardware modification and cutting costs for subsequent intelligent upgrading.
Step 4: Improve supporting technical services to reduce on-site maintenance pressure
Most maintenance staff in sewage plants are non-electrical professionals, and supporting services directly affect equipment operation. During selection, confirm that the supplier can provide electrical schematic diagrams, EPLAN drawings, program backups, BOM lists, factory test reports, as well as on-site commissioning, operation training and spare parts supply services. Shiyou Electric offers one-stop services covering process sorting, scheme design, cabinet assembly, factory simulation testing, on-site commissioning and maintenance training. Before delivery, we simulate operating logic including liquid level variation and pump fault switching to verify control logic in advance, shortening on-site commissioning time and enabling fast equipment commissioning.
In summary, the selection of control cabinets for sewage plants is not simple component assembly. It is a systematic project combining high-humidity corrosive conditions and sewage treatment processes, taking protection, control logic, smart water platform integration, cost and operation maintenance into consideration. Drawing on rich experience in complete electrical control systems, Shiyou Electric provides customized control cabinet solutions for municipal sewage, industrial wastewater, integrated sewage equipment and lift pumping stations to help sewage projects operate stably and meet discharge standards.
