Insulation monitoring and fault location

22 Jun 2021155

In many important industry production sites, especially mines, underground mines and other places, there are very high requirements for power supply safety and stability. Some of the site use IT system (ungrounded power supply system), when the IT system occurs ground fault, the ground fault current is usually very small and does not need to immediately cut off the fault circuit. So equipped a detect system to continuity monitor IT system working situation and locate the fault circuit can make sure power supply reliability, also can guide maintainer worker to troubleshooting.

 

A highly reliable monitoring system needs to include functions such as insulation resistance monitoring, insulation failure pre-warning and alarm, event recording. It should free to set monitor parameter for different site situation, and provide communication function to send data / value to remote host.

 

When a ground fault occurs in the system, it can promptly alarm and accurately locate the specific circuit where the fault occurred, so as to remind electric maintain staff to troubleshoot the fault in time.

 

insulation monitoring device must trigger a visual and / or acoustic signal when the first fault occurs. Malfunctions as a result of insulation faults and the associated cost-intensive interruptions to operation, personal injury and damage to property are avoided. The insulation monitor was developed especially for use in modern power supplies, which often also contain converters, power converters, thyristor controllers or directly connected DC components. EMC interference suppression measures with their leakage capacitances to ground play a major role there.

 

The insulation monitor is connected between the active system conductors and earth. With active measuring methods, it superimposes a measuring voltage on the network. If there is an insulation fault, the measuring circuit closes and a small current proportional to the insulation fault flows. This measuring current is evaluated by the electronics of the device. If the insulation resistance falls below a certain value (response value), a message is issued by the device. Insulation monitoring devices of the VARIMETER IMD family are available for direct voltage (DC), alternating voltage (AC) and mixed networks (AC/DC), e.g. networks with voltage or frequency changes, high system leakage capacitances or DC voltage components.

 

The insulation monitor is connected between the active system conductors and earth. It superimposes a measuring voltage on the network. If there is an insulation fault in a certain sub-circuit, the measuring circuit closes and a small current proportional to the insulation fault flows. This current signal be detected by monitor device, if insulation resistance falls below a preset value, device will transmit alarm information in RS485 network, worker in remote monitor center will know this situation.

 

More application area:

 

Insulation monitoring in medical technology as well as in data centers and IT. Making ships, ports and gantry cranes electrically safe with insulation monitors. High system availability also for renewable energies (PV systems) as well as airport and traffic lighting. Electrical safety also for mobile power generators, eMobility and DC charging stations.