SALUS Controls RT520/RT520RF Thermostat and RXRT520 Receiver

Introduction

The RT520 (wired model) and RT520RF (wireless model) thermostats are SALUS RT series devices designed for efficient and comfortable heating control. These new models feature a large LCD display, intuitive programming, and advanced functions. Key innovations include the OpenTherm protocol and the TPI (Time Proportional & Integral) algorithm, which optimize heating system performance based on room conditions.

Please read this manual carefully before use.

Safety Information

• Use the equipment strictly according to this instruction manual.
• This device is intended for indoor use only.
• Installation must be performed by a competent specialist.
• Installation must comply with all applicable local, national, and state regulations and guidelines.
• Failure to adhere to these instructions, standards, and regulations may result in device damage, personal injury, death, or legal prosecution.

Compliance Information: The equipment complies with Directives: EMC 2014/30/EU, LVD 2014/35/EU, RED 2014/53/EU, and RoHS 2011/65/EU. Full Declaration of Conformity is available at: www.saluslegal.com

Radio Frequency: 868.0-868.6MHz; <13dBm

Technical Specifications

Thermostat RT520 / Thermostat RT520TX (Transmitter)

Receiver RXRT520

Button Functions

RT520/RT520RF Thermostat:

1. MENU: Enter menu; press and hold for approx. 3 seconds to return to the main screen or deactivate Boost mode.
2. SELECT: Confirm selection, enter menu.
3. DOWN: Lower set temperature, move to the next function in the menu.
4. UP: Raise set temperature, move to the previous function in the menu.
5. BOOST: Activates Boost mode (temporary manual operation).
6. MANUAL: Activates/deactivates manual mode.

RXRT520 Receiver:

7. ON: In manual mode, turns the connected heating system ON.
8. OFF: In manual mode, turns the connected heating system OFF.
9. AUTO: The receiver operates in automatic mode, following commands sent by the thermostat.
10. MANUAL: The receiver operates based on the position of the lower ON/OFF switch.

Screen Icon Descriptions

• Text panel: Displays various information messages.
• AM/PM indicator: Shows if the time is before or after noon.
• Day of week (numeric): Displays the current day of the week as a number (e.g., 1 for Monday).
• Holiday mode - ON: Indicates that the holiday mode is active.
• Units of measurement: Shows the temperature unit (°C or °F).
• Cooling Mode - ON: Indicates that the cooling function is active.
• Day of week (alphabetic): Displays the current day of the week as a letter (e.g., Mon).
• Manual Mode - ON: Indicates that manual mode is active.
• Time: Displays the current time.
• Heating Mode - ON: Indicates that the heating function is active.
• Wireless communication with receiver: Shows the status of the wireless connection to the receiver.
• Program number: Displays the currently active program number.
• Program indicator: Shows the status of the active program.
• Battery status indicator: Indicates the battery level of the thermostat.
• Measured/Set temperature: Shows the current room temperature and the target set temperature.
• Service Mode - ON: Indicates that the service mode is active.
• Settings: Icon indicating access to settings.
• Boost Mode: Icon indicating that Boost mode is active.

Terminal Descriptions

RT520 Thermostat Terminals

RXRT520 Receiver Terminals

Installation and Wiring

General Installation Notes:

• Before installation, repair, or maintenance, always disconnect the power supply, even when replacing batteries.
• Use only alkaline AA 1.5V batteries. Do not use rechargeable batteries.
• Insert batteries into the compartment located on the back of the thermostat.
• Before installing batteries in the thermostat, connect the receiver and its power supply.

Wiring Diagrams:

1. Standard Connection (for TPI or Hysteresis modes):

• Connect the heating system control wires from the receiver (RXRT520) to the thermostat (RT520) terminals:
• RXRT520 NO to RT520 NO
• RXRT520 COM to RT520 COM
• Connect the 230V AC power supply to the RXRT520 receiver:
• L to L
• N to N

2. OpenTherm Connection:

• Connect the OpenTherm communication wires from the thermostat (RT520) to the receiver (RXRT520) terminals:
• RT520 B / A to RXRT520 B / A
• Connect the 230V AC power supply to the RXRT520 receiver:
• L to L
• N to N

Note: The RXRT520 receiver has NO/COM terminals for standard connection and B/A terminals for OpenTherm communication.

Operational Modes and Features

OpenTherm Communication

OpenTherm is a modern boiler control method that modulates (adjusts) the heat output of the boiler. Instead of simply switching the boiler ON/OFF, OpenTherm control adjusts heat delivery based on the room's heating demand, as communicated by the thermostat. This method significantly extends system lifespan, saves energy, and enhances user comfort.

TPI (Time Proportional & Integral) Control

TPI is a self-learning algorithm that proportionally regulates temperature. It allows the system to reach the set temperature more quickly and accurately, adapting to the specific characteristics of each room. By maintaining the set temperature precisely, TPI minimizes energy consumption and reduces costs. The RT520 thermostat offers three TPI control types:

1. For radiator heating (6 cycles per hour - 6CPH)
2. For underfloor heating (3 cycles per hour - 3CPH)
3. For electric heating (9 cycles per hour - 9CPH)

Hysteresis

Hysteresis is the temperature difference between when the connected load turns ON and OFF. For example, if you set the room temperature to 20°C with a hysteresis of 0.5°C, the load will turn ON at 19.75°C and turn OFF at 20.25°C.

Optimal Start

This intelligent function compares current and set temperatures to determine the optimal time to activate the heating system, ensuring the set temperature is reached precisely according to the schedule. It saves energy by activating the system only when necessary and provides user comfort by adhering to the schedule.

Optimal Stop

This intelligent function continuously compares current and set temperatures to calculate how long the room will retain heat after the load is switched off. It then switches off the load in advance. Because this function operates in real-time, its parameters automatically adjust if there is an unexpected loss of heat in the room, preventing overcooling.

Service Settings (Administrator Settings)

This PIN-protected feature allows the heating system installer to configure alerts (displayed on the thermostat) for necessary boiler service inspections. Once activated, the thermostat will be locked but will maintain the temperature set by the administrator. To unlock, the user must contact the installer for a boiler inspection. Administrator settings are not reset.

Initial Setup

After installing batteries in the thermostat, it will power on.

1. Press MENU.
2. Use the DOWN or UP buttons to select the desired language, then press SELECT.
3. Press SELECT.
4. Use the DOWN or UP buttons to set the hour, then press SELECT.
5. Use the DOWN or UP buttons to set the year, then press SELECT.
6. Use the DOWN or UP buttons to set the month, then press SELECT.
7. Use the DOWN or UP buttons to set the minutes, then press SELECT.
8. Use the DOWN or UP buttons to select the time format (12/24 hour), then press SELECT.
9. Use the DOWN or UP buttons to set the day, then press SELECT.
10. Use the DOWN or UP buttons to select the day of the week format (numeric/alphabetic), then press SELECT.
11. Press SELECT to confirm.
12. Use the DOWN or UP buttons to set the temperature display step (0.1°C or 0.5°C), then press SELECT.
13. Use the DOWN or UP buttons to enable or disable DST (Daylight Saving Time), then press SELECT.
14. Press SELECT to confirm.
15. Press SELECT to confirm.

If the thermostat was connected using the OpenTherm terminal, the software will automatically adapt to OpenTherm settings. Press SELECT.

Programming - Auto Mode

In this mode, users can create custom programming schedules with specific temperatures for different time periods. Ensure all time periods are utilized.

Steps:

1. Press MENU.
2. Use the DOWN or UP buttons to navigate to the desired programming type and press SELECT:
   • Each day individually.
   • All days the same (one schedule for all days).
   • +2 (separate schedules for weekdays and weekends).
3. Use the DOWN or UP buttons to select the desired duration (time period) and press SELECT.
4. Use the DOWN or UP buttons to set the desired temperature for that period, then press SELECT.
5. Repeat steps 3 and 4 for all subsequent programs.

TPI/Hysteresis Selection:

IMPORTANT: Use the DOWN or UP buttons to select either TPI (step 2 in programming) or HYSTERESIS (step 6 in programming). Selecting one option excludes the other.

TPI Selection:

1. Press MENU.
2. Navigate to the TPI sub-menu and press SELECT.
3. Use the DOWN or UP buttons to choose the TPI type (6CPH, 3CPH, or 9CPH) and press SELECT.

Hysteresis Selection:

1. Press MENU.
2. Navigate to the HYSTERESIS sub-menu and press SELECT.
3. Use the DOWN or UP buttons to set the desired hysteresis value, then press SELECT.

Pairing Procedure (RT520TX with RXRT520)

If you purchased the RT520RF kit, the devices are already paired. If you purchased the RT520TX transmitter and RXRT520 receiver separately, follow these instructions to pair them:

1. Ensure the receiver (RXRT520) is disconnected from power.
2. Set the receiver to AUTO mode, in the ON position.
3. Connect power to the receiver (230V AC). The red LED on the receiver should light up solid red.
4. Immediately set the switch on the receiver to OFF, then without delay, switch it back to ON. The red LED will start blinking, indicating the receiver is in pairing mode.
5. On the thermostat (RT520TX), press MENU.
6. Use the DOWN or UP buttons to navigate to the PAIRING sub-menu and press SELECT.
7. Press SELECT to initiate pairing.
8. The pairing process may take up to 10 minutes. During pairing, ensure the thermostat and receiver are within 1 meter of each other.
9. When the red LED on the receiver lights up solid red, the devices are successfully paired.
10. The thermostat will return to the main menu.

Service Settings (Administrator)

To access Service Settings:

1. Press MENU.
2. Use the DOWN or UP buttons to navigate to the ADMIN sub-menu and press SELECT.
3. Enter the PIN code using the DOWN or UP buttons, pressing SELECT to confirm each digit.
4. Use the DOWN or UP buttons to select ON or OFF for the service alert, then press SELECT.
5. If enabled, use the DOWN or UP buttons to set the time for the service alert, then press SELECT.
6. Use the DOWN or UP buttons to set the temperature that will be maintained while the thermostat is locked (e.g., during service), then press SELECT.
7. Press SELECT to confirm.

Once Service Mode is activated, the thermostat will be locked but will maintain the administrator-set temperature. To unlock, contact the installer for a boiler inspection. Administrator settings will not be reset.

Factory Reset

To reset all thermostat settings to factory defaults:

Press and hold the MENU, DOWN, and BOOST buttons simultaneously for approximately 5 seconds.

The settings will be reset, and the thermostat will restart.

Testing Correctness of Pairing

After pairing, you can test the connection:

Navigate to the pairing test menu and follow the on-screen prompts. The thermostat will attempt to communicate with the receiver.

Hot Water Settings (OpenTherm Mode)

When using OpenTherm for Hot Water (HW) control:

1. Press MENU.
2. Use the DOWN or UP buttons to navigate to the HW sub-menu and press SELECT.
3. The text panel will display information indicating that HW is being heated.
4. The thermostat will return to the main menu. Press any button to wake the screen.