TDC Solar Controls
Temperature difference controllers by SOREL: versatile and user-friendly. Thanks to the clear operator guidance, various types of solar systems can be operated intuitively – from small to complex.
STDC
“Small” Temperature Difference Controller for simple systems for 9 solar, storage and solid fuel boiler-systems
MTDC
“Medium” Temperature Difference Controller for midsize systems for 25 basic systems with additional functions for unused relays
LTDC
“Large” Temperature Difference Controller for complex systems for 42 basic systems with additional functions for unused relays
XTDC
Xtra large for flexible controlling of complex solar thermal systems with up to 4 storages
MTDC-E
Midsize Temperature Difference Controller for basic solar systems with electric backup heating up to 3kW.
LTDC-E
Large Temperature Difference Controller for basic solar systems with electric backup heating up to 3kW and control of circulation pump.
| STDC | MTDC | LTDC | XTDC | MTDC-E | LTDC-E | |
|---|---|---|---|---|---|---|
| Sensor inputs PT1000 | 3 | 4 | 6 | 8 | 3 | 4 |
| Relay outputs 230V | 1 | 2 | 3 | 6 | 1 | 2 |
| Relay output voltage-free | ✕ | ✕ | ✕ | 1 | 1 | 1 |
| Outputs 0..10V or PWM signal for speed control of high-efficiency pumps |
1 | 1 | 2 | 2 | ✕ | 1 |
| Number of applications | 9 | 25+ | 42+ | 48+ | 4 | 8 |
| Extension of pre-defined systems by selectable additional functions |
✕ | ✓ | ✓ | ✓ | ✕ | ✕ |
| LEDs red/green for display of operating status | ✕ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Statistics and graphic analysis of data memory | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Flow based heat metering via Grundfos direct sensor (VFS / VVX) | ✕ | ✕ | 2 | 2 | ✕ | ✕ |
| Pressure monitoring via Grundfos direct sensor (RPS) | ✕ | ✕ | 2 | 2 | ✕ | ✕ |
| Battery-backed Real Time Clock > 24h | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Time and Temperature-controlled thermostat function | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Legionella function via solar | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Legionella protecion via additional heating | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Cooling function | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Setup wizard | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| System protection | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Collector protection | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Storage protection (CP Tmax) | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Anti-freeze protection | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Recooling | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Start logic for vacuum tube collectors | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Control program for self-dumping systems (drain-back) | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Function control and error memory with date and time | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Menu blocker | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Power supply for universal voltage range (100…240VAC) and reduced standby consumption | ✕ | ✓ | ✓ | ✓ | ✓ | ✓ |
| CAN bus connection for SOREL Connect | ✕ | ✓ | ✓ | ✓ | ✕ | ✕ |
| Data logging on microSD card | ✕ | via data logger | via data logger | ✓ | ✕ | ✕ |
| Ethernet connection | ✕ | via data logger |
via data logger | ✓(only at V2) | ✕ | ✕ |
| Dimensions Height x Width x Depth in mm | 115 x 86 x 45 | 163 x 110 x 51 | 163 x 110 x 51 | 228 x 180 x 53 | 163 x 110 x 51 | 163 x 110 x 51 |
| Housing colour | RAL 9003 | RAL 9003 | RAL 9003 | RAL 9003 | RAL 9003 | RAL 9003 |
| Protection Class | IP40 | IP40 | IP40 | IP40 | IP40 | IP40 |
| Mounting Hardware, Spare Fuse and User Manual | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
PC Simulation
Virtual simulators of any SOREL controller are available free of charge for easy product trial, technical trainings or to facilitate your customer support.
Where to buy
Find your national SOREL contact person or the nearest SOREL retailer: