HAKEL
Hakel is a dynamic company which since foundation in 1994 has quickly developed in terms of turnover and the product assortment. This dynamism can also be observed in the approach to developing the quality of the manufacturing products.
Hakels experience in the use of power electronics in industry, is related to its leading position in the Czech Republic and Europe. Hakel produces and exports to all countries and all continents.
The insulation monitoring devices offered by the company are used for easy application in ungrounded IT power supply systems in metallurgy, civil engineering, shipbuilding, in hospitals and the transport environment:
- Insulation Monitoring Devices for Traction Systems and Vehicles
- Surge Protection Devices for Railways, Traction Systems & Urban Transport
- Inductors for Traction Systems and Vehicles
- Voltage Limiting Device for AC / DC Traction Systems
- Low Voltage Limiter for Railway Applications
IT power supply system
IT power supply system is an insulated system that has all active parts isolated from the earth or one point of the system grounded via high impedance. Inactive parts of the electrical installation are grounded. Ungrounded system increases the operational reliability and human safety. Therefore it is used in the metallurgy, mechanical engineering, shipbuilding, traction systems, public transport and hospitals. The advantage of the ungrounded system is that the device connected to this system can work continuously even in the case of first fault (so-called earth fault). The phase voltage of the undamaged phase (or phases in the three-phase system) is increased to the value of the delta voltage during the first fault. The system is safe if inactive parts are properly grounded. The reason is that there occur no bigger than safe current levels. The relevant responsible person must be informed about this failure and the first fault must be eliminated as soon as possible. However, the second fault (double earth fault) must result in immediate disconnection of the power supply system. The insulation monitoring devices or residual current relays are used for monitoring of the ungrounded system. These devices indicate the insulation level decrease below the set value.
Advantages of IT power supply systems equipped with insulation monitoring devices:
- Operation continuity – in case of first fault (connection between IT power supply system and ground-earth fault) the systems is still operational
- Higher safety of operation
– Immediate overview of network status, continuous monitoring of the insulation level to earth
– Early detection of faulty devices by immediate signalisation by the insulation monitoring device
– Less risk of electric shock for the operator and higher fire safety
– Prevention of production losses and shutdowns, operations can continue in case of a first earth fault - Practice shows that there is an obsolete minimum of the earth connections caused by a step change of insulation resistance. The vast majority of them is caused by gradual deterioration of insulation. HAKEL Insulation Monitoring Devices “ISOLGUARD” are therefore equipped with the display that shows exact numerical values of the insulation resistance and enable to monitor the changing status of the insulation before the origin of the first earth fault.
