For an industrial enterprise’s vacuum heating system package project, Qingdao Xiaoyang Electric designed and manufactured a complete control system using Siemens S7-200 SMART PLC as the control core, paired with international first-tier brand components including Schneider contactors/breakers, Phoenix Contact terminal blocks, and Mean Well power supplies. The system ensures precise control and long-term stable operation of the vacuum heating process.
Project Background
Vacuum heating systems are widely used in high-end industrial fields such as material heat treatment, electronic component packaging, and aerospace component manufacturing. These systems require extremely high temperature control accuracy, vacuum stability, and heating curve repeatability. Any control deviation can lead to product scrap. The customer needed a highly reliable, high-precision PLC control system to achieve fully automatic operation of multi-stage vacuum heating processes.
Customer Pain Points
- High control precision requirements: Vacuum heating requires precise temperature curve control with ±1°C accuracy and vacuum control within ±0.5Pa
- High system reliability requirements: Vacuum heating cycles are long (up to tens of hours per cycle), requiring 24/7 stable operation with no mid-process failures
- Multi-loop coordinated control: The system involves coordinated control of vacuum pumps, heating power, cooling systems, and gas filling circuits with complex logic
- High component quality requirements: The customer explicitly required international first-tier brand components to ensure long-term reliability
Xiaoyang Solution
Addressing the specific needs of vacuum heating systems, Xiaoyang Electric adopted a “high-end components + standardized workmanship” design philosophy:
- Control core: Siemens SIMATIC S7-200 SMART PLC (CPU ST20 + expansion modules) with high-speed counting, PID regulation, and Ethernet communication
- Distribution system: Schneider breakers + disconnect switches with hierarchical protection for distribution safety
- Control system: Schneider TeSys series contactors and Schneider intermediate relays for reliable circuit switching
- Wiring system: Phoenix Contact terminal blocks with clear labeling and reliable connections for easy maintenance
- Power system: Mean Well NDR-240-24 + EDR-150-24 dual 24V DC power supplies for redundant control power
- Cabinet layout: Four-layer independent zoning — PLC/power layer, control layer, distribution layer, relay layer — with strong/weak current separation and good heat dissipation
Core Configuration
| Category | Brand/Model | Qty | Purpose |
|---|---|---|---|
| PLC Controller | Siemens SIMATIC S7-200 SMART CPU ST20 | 1 set | System control core |
| PLC Expansion | Siemens S7-200 SMART Digital/Analog modules | 4 pcs | IO expansion |
| Power Supply | Mean Well NDR-240-24 (24V/10A) | 1 unit | Main control power |
| Power Supply | Mean Well EDR-150-24 (24V/6.5A) | 1 unit | Backup/sensor power |
| AC Contactor | Schneider TeSys LC1D series | 8 units | Pump/heating/cooling control |
| Circuit Breaker | Schneider Easy9/OSF series | 10+ ch | Circuit protection |
| Intermediate Relay | Schneider RXM series | 5 pcs | Signal isolation/expansion |
| Terminal Block | Phoenix Contact UK series | 100+ pos | Signal/power wiring |
| Cabinet | IP54 protection rating | 1 unit | Equipment protection |
Workmanship & Quality
Xiaoyang Electric strictly follows IEC 61439 standards for manufacturing:
- Standard wiring: All cables routed in ducts with strong/weak current separation and complete wire identification
- Four-layer layout: Independent zoning for PLC/power, control, distribution, and relay layers for easy maintenance
- Component labeling: Each component has a yellow label (KM1/KM2/QF1, etc.) matching the drawings
- Factory testing: 72-hour continuous power-on aging test, full IO point inspection, and control logic commissioning
- Documentation: Complete delivery of electrical schematics, IO point lists, component lists, and operation manuals
Results
- System operates stably after commissioning, with vacuum heating process control accuracy meeting design requirements
- Temperature control accuracy ±0.8°C, vacuum control accuracy ±0.3Pa, exceeding customer requirements
- Fully automatic multi-stage process curve operation without manual intervention, significantly improving product consistency
- Customer highly praised the component configuration, wiring workmanship, and system stability
Customer Testimonial
“The configuration and workmanship of this vacuum heating control system met our expectations. The Siemens PLC + Schneider + Phoenix Contact combination is stable and reliable, the cabinet wiring is standard and neat, and commissioning passed on the first try. Xiaoyang Electric’s professional capability is trustworthy.”
—— Project Equipment Manager
Qingdao Xiaoyang Electric Technology Co., Ltd. | High-end PLC control system integrator, specializing in Siemens/Schneider/ABB and other international brand component packages, providing high-quality electrical solutions for industrial automation.
Related products: PLC Smart Control Cabinet | Custom Electrical Solutions | Low-Voltage Distribution Box
Project Photos
