(This case is anonymized; client name and specific location are withheld.)
Project Background
A large water treatment plant in East China had been operating its original PLC control system for over 10 years. Three problems became urgent: aging components caused rising failure rates that destabilized output during summer peaks; the original manufacturer had discontinued spare parts, leading to long lead times and high prices; and the system had no remote monitoring capability, requiring staff to be on-site at all times.
Client Pain Points
- High failure rate of the old control system, fluctuating water quality in summer
- Difficult spare parts procurement — a single fault could mean weeks of waiting
- No remote monitoring, requiring 24/7 on-site operators
- Missing original drawings and documentation, making upgrades difficult
Xiaoyang Solution
We redesigned the complete PLC control system with the following configuration:
- PLC CPU: Siemens S7-1200, unifying the brand across the plant for future expansion
- HMI touchscreen: 10-inch color display with real-time process flow diagrams
- Remote monitoring: Ethernet communication module enabling mobile app and PC remote access
- Field enclosure rating: IP54 enclosures for damp process areas to prevent moisture ingress
- Documentation rebuild: Complete new schematics, BOM, and operation manual
The upgrade was implemented in segments without stopping production — new cabinets were installed, hot-switched, verified, and only then were old equipment removed — minimizing disruption to plant operations.
Results
| Metric | Before | After |
|---|---|---|
| Annual failure rate | 2–3 times per month | Reduced by ~80% |
| O&M cost | 3 on-site staff | Reduced by ~40% (remote diagnosis) |
| Fault response | On-site required | Remote diagnosis + on-site when needed |
| Spare parts | Weeks of waiting | Common parts in stock |
After acceptance, the system ran continuously for two years without production stoppage due to control system faults, with stable water quality compliance.
Explore Water Treatment Solutions
If your water treatment plant faces aging controls, hard-to-find spares, or needs remote monitoring, view our water treatment electrical solution or contact our engineers for tailored advice.
Related Products
- PLC Control Cabinet — Siemens S7 series custom builds
- Outdoor Waterproof Enclosure — field enclosures for damp areas