Specifically designed to monitor the condition of 100V line Speaker systems in emergency paging and fire evacuation installations. Many large commercial installations have speaker circuits in excess of 250W. Traditional line monitoring units were limited to 50W per zone and would not handle this load. The A 4567B can handle loads up to 500W per zone. The microprocessor controlled circuit continuously monitors loudSpeaker lines for normal, open or short circuit condition. A multi-colour LED indicates line condition accordingly for each zone. Internal audible alarm buzzer with cancel button is fitted. With any fault condition, a switched output is provided for remote monitoring purposes. This is a switched to ground signal. Three outputs are supplied. One for short circuit conditions. One for an open circuit fault. Plus a combined output for any fault condition. The system can be configured to operate with multiple amplifiers. Dimensions: 482 x 152 x 44mm.