Specifications RMT GRJ
The purpose of an earth resistor of the star centre is to protect transformers and generators from short circuits between phases and between phases and the earth connection. In fact, when a resistor is inserted between the star and the earth connection the short circuit current is limited to a pre-set value that does not damage the equipment connected.
Additionally, the use of the resistor has the following advantages over other systems:
· It minimizes damage caused by mono phase failures at the earth connection;
· It prevents the formation of temporary overloads;
· It limits the electro dynamic strain deriving from external breakdowns (in the network and down line);
· It decreases needless interruptions by protective devices.
Features RMT GRJ
Tolerance on resistance value: ±10%
Temperature coefficient depending on the type of material used
Maximum utilisation temperature: 55+750 [°C]
Insulation current depends on requirements
Minimum resistance value depends on the number of elements
Maximum resistance value depends on the number of elements
Level of protection (IEC 529) IP 00
Maximum temperature reached on elements at end of transit 450 [°K]
