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Fixed time overcurrent protection principle wiring diagram

Circuit DescriptionA 12-pulse rectifier is used as the current source to provide a DC test current, while a voltage oscillation circuit provides the recovery voltage after current switching. Auxiliary breakers and spark gaps are implemented in the circuit to connect these two sources to the test object at specific intervals. The specific implementation is as follows:12-Pulse Rectifier: The rectifier is controlled to provide a DC test current to the test breaker (TB) through a smoothing reactor L

What is Diode Test ?Diode DefinitionA diode is defined as a semiconductor device that allows electric current to flow in one direction only.Diode Test ModeThis mode on digital multimeters applies a small voltage to a diode and measures the voltage drop, indicating the diode’s condition.To test a diode with diode test mode Turn off the power source of the circuit that contains the diode. If possible, remove the diode from the circuit for more accurate results. Set the multimeter to diode test mod

What is the Hopkinson Test?The Hopkinson test definitionThe Hopkinson test is a useful method to test the efficiency of DC motors. It requires two identical machines, one acting as a generator and the other as a motor. The generator provides mechanical power to the motor, which then drives the generator. This setup is why the Hopkinson test is also known as back-to-back or regenerative testing.If there is no loss, no external power supply is required. However, since the generator output voltage

What is Swinburne Test of DC Machine?Swinburne Test DefinitionThe Swinburne test is an indirect method for testing DC machines, named after Sir James Swinburne. It’s a simple and common test for shunt and compound wound DC machines with constant flux. This test pre-determines the machine’s efficiency at any load by running it as either a motor or generator and measuring no load losses separately.The circuit setup for Swinburne’s test uses a shunt regulator to adjust the machine’s speed to the ra

What is Blocked Rotor Test of Induction Motor?Blocked Rotor Test DefinitionThe blocked rotor test of an induction motor is defined as a test to find the leakage impedance and other performance parameters.Purpose of Blocked Rotor TestIt determines torque, motor characteristics, and short-circuit current at normal voltage.Testing ProcedureDuring the test, the rotor is blocked, and low voltage is applied to the stator to measure voltage, power, and current.Effect on ImpedanceRotor position, frequen

What is No Load Test of Induction Motor?No Load Test of Induction Motor DefinitionA no load test of induction motor is defined as a test conducted when the rotor rotates at synchronous speed without any load torque.Purpose of No Load TestThis test helps identify no-load losses like core loss, friction loss, and windage loss.Theory of TestThe test assumes that the impedance of the magnetizing path is large, causing small current flow and the applied voltage is across the magnetizing branch.Test P

What is Testing of Induction Motor?Induction Motor DefinitionAn induction motor is defined as a type of electric motor that operates on the principle of electromagnetic induction.Basic Parameters Current Voltage Power ResistancePreliminary Tests Firstly check the components of motor No-load running current test High potential test Air-gap measurement Balancing of current Temperature rise in bearing Voltages in shaft Direction of rotation Level of noise Strength of vibration Air gap eccentricity

What is Transformer Acidity Test?Acidity Test DefinitionThe acidity test of transformer oil measures the amount of potassium hydroxide (KOH) needed to neutralize the acid in the oil.Causes of AcidityAcidity occurs due to oxidation, especially when oil contacts air, and is accelerated by heat and metals like iron and copper.Effects of AcidityHigher acidity lowers oilresistivity, increases the dissipation factor, and can harm transformer insulation.Acidity Test Kit ComponentsWe can determine the a

What is Transformer Water Content Test?Water Content Test DefinitionThe water content test in insulating oil is defined as a process using Karl Fischer Titration to measure water levels.Karl Fischer PrincipleTo measure water content in insulating oil, we use Karl Fischer Titration. In this method, water (H2O) reacts chemically with iodine (I2), sulfur dioxide (SO2), an organic base (C5H5C), and alcohol (CH3OH) in an organic solvent.The sample is mixed with sulfur dioxide, iodide ions, and an org