High Current Load Cycle Test Systems are designed to raise and control the temperature of a solid dielectric cable or other short circuit electrical loops to preset levels in order to simulate the current loading conditions found in electrical circuits. This heating is achieved by utilizing the test loop as the secondary winding of a current transformer. Typical test scenarios require that high voltage is applied to the test sample simultaneously with the heating current, preventing the direct measurement of the conductor temperature during the test cycle.
The current transformers utilized in the test system are designed to provide maximum efficiency and flexibility across a wide range of test scenarios. A single current transformer can provide heating current to typical low impedance loops. As the desired test length changes, additional current transformers can be added or removed from a system to provide the required heating current.
Most test loops are highly inductive, with the actual losses presenting only a small portion of the required power. Due to this phenomenon, capacitors are utilized to minimize the actual power required from the local source, minimizing the operating costs of the system. A typical system is provided with a source power requirement limited to the rating of one current transformer. This provides a suitable safety margin to accommodate the resistive losses in the test cable.