Insulation monitor for pure 3 phase and alternating current systems, AI897
Adjustable response value 10 → 80 kΩ No separate auxiliary voltage connection required 1 changeover Overall width 45 mm
The AI897 insulation monitor displays the insulation resistance of unearthed 3 phase and alternating current systems to earth. The device works according to the quiescent current principle, that is, the output relay responds when mains voltage is applied to terminals A1 → A2. The output relay breaks when the response setpoint is undercut. A bridge between terminals LT1 and LT2 allows the AI897 to be programmed for memory storage behaviour; remove the bridge to programme hysteresis behaviour. The bridge can be replaced with a delete key with an NC contact. There is a PT test button on the front of the device to test for functional efficiency. An external test button (in accordance with VDE 0413) is also possible.
