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 medium-sized systems for 25 basic systems with switchable functions for unused relays
LTDC
“Large” temperature difference controller for larger solar systems for 42 basic systems with switchable 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 simple solar systems with electronic roof heating up to 3 kW.
LTDC-E
Large temperature difference controller for simple solar systems with electronic roof heating up to 3 kW and circulation pump control.
POOL TDC M
Solar Pool Controller
POOL TDC M Plus
Solar pool controller with filter pump running time control
Advantages of SOREL solar controls
Full text menu
Clearly understandable, context-sensitive help texts explain each setting value.
Setup Wizard
Guides step by step through all necessary settings for quick and easy commissioning.
Graphic display
Animated visualisation of the system, clear characteristic curves and energy statistics.
Modular principle
The systems can be flexibly expanded by activating additional functions using free relays.
Multilingual
Various menu languages can be freely selected for clear communication.
PC-Simulation
Free Windows software simplifies training, functional testing and technical support.
Networkable
Controllers can be networked via CAN bus or connected to the Internet.
0…10V/PWM outputs
For speed control of high-efficiency pumps.
Data logging
Via Micro SD card for storage and evaluation of system data.
CAN-Bus
For internet connection via the data logger or for system optimisation through communication with our system controllers.
| 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 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
The setup wizard guides you quickly through the settings to be made in a logical sequence. This prevents incorrect settings and facilitates parameterisation.
The current measured values and operating states are displayed in an animated overview. In addition, important functions are shown as symbols in the display.
Settings with full text – Explanations
Additional functions: Relay selection
Selection of the Additional functions
Setting the Additional function Thermostat
Functional control and long-term monitoring of the system is made possible by recording and evaluating the data.
Graphical evaluation Legend
- Temp. difference
- Pressure monitoring
- Heating circuit
- Always On
- Booster pump
- Error message
- Antilegionella
- Storage transfer
- Cooling
- Return flow increase
- Reheating
- Solid fuel boiler
- Antilegionella
- Storage transfer
- Cooling
- Return flow increase
- Solar bypass
- Parallel operation
MTDC System 1 + Solar Bypass
Solar with storage with additional function Solar Bypass
LTDC System 14 + solid fuel boiler
Solar with heat exchanger with additional function Solid fuel boiler
XTDC System 20 + additional heating
Solar with 2-zone storage and switching valve with additional function thermostat (additional heating)
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: