Reliable insulation monitoring in mixed IT networks
Undetected insulation faults in non-earthed networks may lead to accidents with considerable personal injuries and property damages. Monitoring of IT networks by insulation monitors is therefore normatively mandated. The insulation monitor LK 5896 from the VARIMETER IMD series by DOLD was developed especially for use in modern power supply systems.
These often include inverters, rectifiers, thyristor controllers and directly connected direct current components. Because of EMC interference suppression measures, high discharge capacities against earth are often present in these systems. The LK 5896 meets these requirements. It is suitable for network discharge capacities up to 3000 μF as well as for voltages up to DC 1500 V and AC 1100 V.
In addition to an adjustable alarm threshold, the insulation monitor features an adjustable prewarning threshold. The device is simply adjusted with a screwdriver on rotary switches. An LED chain as well as an analogue output constantly informs about the current insulation resistance. The insulation monitor does not require any ballasting and guarantees reliable monitoring even if the network is without voltage. A selective earth fault detection to L+ and L- enables quick fault localisation. An additional measurement circuit allows simultaneous monitoring of an AC network which is galvanically isolated from the main measurement circuit.
The LK 5896 increases the availability of systems and provides preventive fire and system protection. The insulation monitor is employed, for example, in UPS systems, photovoltaic systems, hybrid and battery-powered vehicles, etc.
