The RCS Audio-Systems LR-112R is a volume controller for 100-V amplifier systems, designed for use in sound systems for rooms with permanently installed speaker systems. It enables individual volume control at individual outlets and is equipped with a mandatory reception relay that automatically switches the volume to maximum level during priority announcements (e.g., emergency calls or alarm signals), ensuring that important messages are not masked. The controller is rated for a maximum load of 12 watts and features an integrated 100-V transformer, enabling adaptation to the high-voltage network of the sound system.

Applications
The LR-112R is suitable for use in office buildings, schools, hospitals, shopping centers, or other facilities where centralized sound distribution with decentralized volume control is required. The integrated priority function makes it particularly suitable for applications involving safety or information functions, where interruption of normal music or background sound by important messages is necessary. Installation is carried out in standard flush-mounted boxes with a diameter of 55 mm, ensuring universal compatibility with existing electrical installations.

Functions and Features in Detail
The volume controller features ten adjustment steps, each providing 3 dB of attenuation. Additionally, there is a zero position that completely interrupts the signal path. The steps are designed to allow continuous volume control without requiring the user to read the exact position. The switch is protected against intentional over-rotation, enhancing the mechanical integrity of the device and the safety of the installation. The cover plate and frame are finished in pure white (also referred to as alpine white), enabling seamless integration into the surrounding environment.

Technology Explained Simply
The 100-V transformer in the LR-112R is used to match the device to the high-voltage lines commonly used in professional sound systems. This technology allows for long cable runs with minimal losses, as signals are transmitted at elevated voltage. The 3-dB attenuation steps correspond to a meaningful volume increment that is easily perceptible to the human auditory system. The mandatory reception relay automatically switches to full volume when a signal from a priority source (e.g., an emergency call system) is received, raising the volume to maximum regardless of the previous setting.

Compatibility and Accessories
The LR-112R is designed for installation in standard flush-mounted boxes with a 55 mm diameter. It is part of a system compatible with 100-V amplifiers and speakers. The integrated priority function requires a corresponding control unit to activate the relay. No specific accessories are mentioned in the sources, but compatibility with other components of the RCS system is possible, provided they support 100-V technology.

Installation and Mounting
Mounting is performed in a 55-mm flush-mounted box, with the cover plate and frame installed in pure white. Installation does not require special tools, but electrical wiring must comply with applicable standards. Connections are made to the device's terminals, which are designed for 100-V lines. The mechanical protection against over-rotation simplifies installation, as no additional protective measures are required.

Operational Advantages
The LR-112R provides reliable volume control with an integrated priority function, ensuring that important messages are always heard. The 10-step adjustment in 3-dB increments allows precise adaptation to the specific environment. The mechanical protection prevents damage from improper handling. The pure white finish ensures discreet integration into the environment, making the device visually blend into the wall without appearing as a technical component.