In the verification of current transformer, it is used to simulate the secondary load of the transformer under test.
The current load of the device is connected in series between the K2 of the test current transformer and the Tx of the calibration instrument.
Adjust the load to match the actual secondary load of the test current transformer. Note: Some current transformers specify their secondary load in terms of capacity (VA), while the load of a current transformer's load box is typically expressed as resistance (Ω). The conversion formula is: Capacity (VA) = Resistance (Ω) × Secondary current (A). Customized load boxes with specific requirements can be designed according to user specifications.
The current load box's resistance is reduced by 0.06Ω for external wires, accounting for the combined resistance of the load and connecting wires when the tested transformer is in use. For cosΦ=1 at 0.4Ω setting, the actual load box resistance is 0.34Ω; for cosΦ=0.8 at 0.4Ω setting, the actual load box resistance is 0.26Ω (0.4×0.8-0.06).
Rated capacity: 2.5VA-60VA for cosΦ=0.8, 2.5VA-20VA for cosΦ=1.0.
Measurement range: (5A) 1%-120%, (1A) 5%-120%.
Secondary current: 5A,1A.
Power factor: 0.8, 1.0.
Accuracy: ±3%.