Static Contact Resistance (GIS)
The static contact resistance belongs to the most important tests on circuit breakers. The test verifies whether the resistance of the current carrying contacts allows the flow of rated current within specified losses. The resistance depends on contact surface properties which are the connection points on micro-scoping level, the contact pressure and the oxidation of the surface. A temperature increase above the specified limits changes the electrical contact surface properties which then leads to an increase of losses. This self-accelerated process can develop constantly over years until it accelerated dramatically at the end. Typical resistances values are between 10 to 100 μΩ.
CIBANO 500 outputs up to 200 A DC for static contact resistance measurements with very high accuracy with a digital μΩ meter. Both sides grounded contact resistance measurement is supported for Air Insulated Switchgear (AIS) and Gas Insulated Switchgear (GIS).
Additionally, a demagnetization function is provided which removes any remanences in current transformers. This is a very handy feature for GIS or Dead Tank Design types where the current transformers might be in the contact resistance measuring path.
Benefits of this solution
All important tests on breakers
Powerful integrated supply
High measurement accuracy
The multifunctional CPC 100 can output up to 400 A DC for static contact resistance measurements.
The multifunctional COMPANO 100 provides up to 100 A DC to measure static contact resistance.