Thyristors power controller PR3-SPM series

three-phase

The PR3-E S/SP/SPM range of thyristor stacks provide full, seamless control, of three phase, resistive loads using a two thirds control technique. Control of the power level is either by a dc signal or by manual control using a 5kΩ potentiometer. The PR3-E burst firing control stacks use fast pulse, zero volts switching technology, to minimise flicker and eliminate RFI problems. The controllers also incorporate an automatically resetting temperature trip, integral semiconductor fuses, and an integral volt free trip/enable input for wiring of an external thermal trip. The range contains two power ratings: 27kW and 36kW. For each power rating, three versions are available: S(standard – without high speed (HS) fuses and without internal power supply), SP (Standard Plus – including HS fuses and internal power supply) and SPM (Standard Plus Monitoring) version – including HS fuses, internal power supply and SCR/HS Fuse monitoring). All have 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 Trip/Enable Input This input should be driven by a volt free contact. When the contact is closed the unit is enabled to supply power to the load. When the contact is open this disables the power to the load. If this input is not used a wire link must be fitted to enable the unit. Alarm Relay Output (3-way terminal – Volt Free Contacts, Normally Open (NO), Normally Closed (NC), Common (COM).