Thyristors power controller PR3 series

burstthree-phase

This PR3 range of thyristor stack provides full seamless control of three phase resistive loads, using two thirds control technique. Signal control is by a dc signal or manual control via a 5kΩ potentiometer. This burst firing control stacks use fast pulse zero volts switching technology, to minimise flicker and eliminate RFI problems, it also incorporates an auto-reset temperature trip, integral semiconductor fuses and heatsink. This model, which is naturally air cooled and has easy access to signal & power terminals for simple installation. APPLICATIONS Suitable for 3-wire, 3-phase floating-star or closed-delta configured resistive loads. This includes the Heating, Ventilating and Air Conditioning (HVAC) market for air curtain applications, but also for furnaces, ovens, dryers and hot plates. FUNCTIONS Alarm relay functions (3-way terminal – V/free alarm “NO_NC_C”) The alarm circuit has voltage free relay contacts and are rated up to 2A @ 125V ac (RMS) load. The internal supply to the relay is obtained from the transformer via two 20mm 1A fuses. These are connected to the L1 and L2 phases and therefore the relay and LED can only energise when there is an over-temperature condition, a sensor fault, or a L3 phase loss. Over temperature protection When a heatsink temperature of above 90ºC is detected by the sensor, the alarms relay changes state and the LED pulses rapidly. The power to the load will be disconnected and will not return until the temperature drops to 85ºC. Temperature sensor loss LED status changes to ON/OFF (fast pulsing) if the sensor fails