Thermal Energy Recovery Control System — Dual-Bay Siemens Panel Build
Sector:
Renewable Energy
Type:
New Build - Control System
Platform:
Siemens
Certification:
CE / UKCA
Summary
DelaControl designed and built a dual-bay electrical control panel for a thermal energy recovery system, incorporating Siemens variable frequency drives, a SIMATIC S7-1200 PLC with ET 200SP distributed I/O, a 12-inch comfort HMI, and an IIoT remote access gateway — all delivered with a full documentation pack and factory acceptance test.
Challenge
A thermal energy recovery system required a purpose-built electrical control panel to manage an exhaust fan and a pump, each driven by a variable frequency drive. The panel needed to be designed and built to the customer's own control panel standard, incorporating specific Siemens drive models and meeting defined IP and thermal performance requirements.
The scope required a complete documentation package — including electrical schematics, safety engineering assessment, thermal calculations, and a Declaration of Conformity — as well as pre-delivery testing and a witnessed factory acceptance test. Software generation and site commissioning were outside the required scope, to be handled separately by the end user.
Solution
DelaControl designed and built a dual-bay Rittal VX25 enclosure (IP55, RAL 7035) with a divider plate separating the power and controls sections, mounted on a 200 mm plinth. The power section houses an 80 A fused switch isolator with external door-mounted handle, motor protection circuit breakers, and two Siemens SINAMICS G120X variable frequency drives — a 15 kW unit for the exhaust fan and a 5.5 kW unit for the pump — both communicating via Profinet. A Rittal Blue e+ cooling unit manages internal thermal conditions within the specified limits, verified using Rittal Therm software calculations supplied as part of the documentation.
The controls section is built around a Siemens SIMATIC S7-1200 G2 PLC with an ET 200SP distributed I/O head station, providing digital and analogue input and output modules to suit the system's instrumentation and valve control requirements. A Siemens SIMATIC TP1200 Comfort 12.1-inch HMI panel provides local operator interface, and an Ewon Flexy IIoT gateway with 4G LTE extension card and antenna enables secure remote access to the system.
Safety functions — covering emergency stop de-energisation of both drives, two electric drives at 24 V, and three valve actuator close signals — are implemented using a Pilz PNOZsigma dual-channel safety relay, with the achieved Performance Level documented in a SISTEMA report (ISO 13849-1). The full documentation package includes general arrangement and schematic drawings (AutoCAD Inventor / AutoCAD Electrical or Eplan), a cable schedule, bill of materials, network diagram, thermal calculations, FAT schedule, FAT certificate, and Declaration of Conformity to LVD and EMC directives.
Key Facts
• Dual-bay Rittal VX25 enclosure (1800H × 600W × 500D per bay), IP55, RAL 7035, with 200 mm plinth
• Two Siemens SINAMICS G120X VFDs: 15 kW (exhaust fan) and 5.5 kW (pump), Profinet communications
• Siemens SIMATIC S7-1200 G2 PLC with ET 200SP distributed I/O head station
• ET 200SP I/O: 3× DI 8x24V DC modules, 5× AI 8-channel analogue input modules, 2× analogue output modules
• Siemens SIMATIC TP1200 Comfort 12.1-inch TFT HMI (1280 × 800)
• Ewon Flexy IIoT gateway with 4G LTE extension card for secure remote access
• Pilz PNOZsigma dual-channel safety relay; SISTEMA report (ISO 13849-1) provided
• 80 A fused switch isolator with door-mounted external handle
• Siemens SCALANCE 8-port unmanaged Ethernet switch for Profinet network
• Full documentation pack: GAs, schematics, cable schedule, BOM, network diagram, thermal calculations, FAT schedule/certificate, Declaration of Conformity