Salus RT520 & RT520RF Programmable Thermostats
This document provides an overview of the Salus RT520 and RT520RF programmable thermostats, highlighting their features, specifications, and connectivity options, particularly their integration with the OpenTherm protocol.
Salus RT520: Wired Programmable Thermostat
The RT520 is a wired, electronic, programmable thermostat designed for precise temperature control.
Key Features:
- Compatibility with OpenTherm protocol (OT+ 4.0).
- Volt-free (potential-free) output rated at 3 (1) A.
- Supports both Heating and Cooling functions.
- Designed for wall mounting.
- Utilizes the TPI (Time Proportional Integral) algorithm for efficient control.
- Features an advanced service settings mode.
Specifications:
| Parameter | Value |
|---|---|
| Thermostat Power Supply | 2 x AA alkaline batteries |
| Temperature Regulation Range | 5 – 33.5°C |
| Output | NO/COM or OpenTherm |
| Dimensions [mm] | 118 x 95 x 26 |
Salus RT520RF: Wireless Programmable Thermostat
The RT520RF is a wireless, electronic, programmable thermostat offering flexible installation and advanced features.
Key Features:
- Compatibility with OpenTherm protocol (OT+ 4.0).
- Volt-free (potential-free) output rated at 3 (1) A.
- Supports both Heating and Cooling functions.
- Can be freestanding or wall-mounted.
- Utilizes the TPI (Time Proportional Integral) algorithm.
- Wireless operating range up to 100 m in open space, up to 35 m in typical buildings.
- Devices are paired by default.
- Features an advanced service settings mode.
- Compatible with the new series of RT receivers.
Specifications:
| Parameter | Value |
|---|---|
| Thermostat Power Supply | 2 x AA alkaline batteries |
| Receiver Power Supply | 230 V AC |
| Temperature Regulation Range | 5 – 33.5°C |
| Radio Signal Frequency | 868 MHz |
| Output | NO/COM or OpenTherm |
| Dimensions [mm] | Thermostat: 118 x 95 x 26 Receiver: 96 x 96 x 27 |
OpenTherm Protocol Integration
The OpenTherm protocol enables two-way communication between the boiler and the thermostat, offering advanced control capabilities:
- Automatic detection of connected devices.
- Display of boiler error codes.
- Control of domestic hot water (DHW) temperature.
- Modulation of boiler power for maximum efficiency and comfort.
TPI Algorithm
The integrated TPI algorithm allows selection for different heating system types:
- Underfloor Heating ♨️ (Icon representing underfloor heating)
- Radiator Heating ♨️ (Icon representing radiator heating)
- Electric Heaters ⚡ (Icon representing electric heaters)
The TPI algorithm ensures precise temperature maintenance by intelligently managing boiler operation.
Advanced Settings
The thermostats offer various settings for optimized performance:
- Hysteresis: Selectable at 0.5°C or 0.25°C. ⚙️ (Gear icon)
- Optimal Start/Stop Function: Intelligently manages heating system start and stop times to reach the set temperature precisely when needed. ⏰ (Clock icon)
- Temperature Accuracy: Displayed temperature accuracy is 0.5°C or 0.1°C. ?️ (Thermometer icon)
- Mode: Supports Heating / Cooling modes. ❄️☀️ (Snowflake and Sun icons)
LCD Screen Features
The thermostats feature a large and easily readable LCD screen, making them suitable for users with visual impairments or the elderly. The menu is intuitive and available in 8 languages. The screen includes backlighting for improved visibility.
? (Lightbulb icon representing illumination/display)
Extended Service Settings
Advanced configuration options are available for installers and property managers:
- Landlord Solution: Convenient settings for property management. ? (Building icon)
- Password Protection: Access to service settings is protected by a password. ? (Lock icon)
- Temperature Limits: Ability to set maximum and minimum temperature restrictions. ?️ (Thermometer icon)
- RF Version Receiver Manual Switch: For the RT520RF, manual control can be activated via a switch on the receiver. ? (Crossed-out signal icon indicating manual override or disabling wireless)
Wiring and Connectivity
OpenTherm communication uses terminals A and B.
RT520 (Wired) Wiring:
The RT520 connects to the boiler via a mounting plate. It can be configured for OpenTherm communication or for TPI/Hysteresis control using COM, NO, or NC terminals.
- OpenTherm Connection: Terminals A and B on the thermostat connect to the boiler's OpenTherm terminals.
- TPI/Hysteresis Connection: Terminals COM, NO, and NC on the thermostat connect to the boiler's heating circuit control.
Diagram Description: Shows a block for the RT520 thermostat with terminals labeled B and A. Another diagram shows a boiler with terminals COM, NO, NC. An 'OR' symbol connects these two configurations.
RT520RF (Wireless) Wiring:
The RT520RF system consists of a wireless thermostat (RT520TX) and a receiver (RT520RX).
- Thermostat (RT520TX): Communicates wirelessly with the receiver. ? (Wi-Fi symbol)
- Receiver (RT520RX): Connects to the boiler. It has terminals for power (L, N) and control (COM, NO, NC), and also supports OpenTherm communication via terminals A and B. The receiver is powered by 230V AC.
Diagram Description: Shows the RT520TX thermostat with a wireless signal icon. Below it, the RT520RX receiver is shown connected to a boiler. The receiver has terminals L, N, COM, NO, NC, and A, B. It is powered by AC 230V. An 'OR' symbol connects two possible configurations for the receiver's control output (TPI/Hysteresis via COM/NO/NC or OpenTherm via A/B).
Further Information
For more detailed information about Salus Controls equipment, please visit their official websites:
