Handheld DMM with capacitance measurement are designed primarily as a DMM but use a DC technique to measure capacitance. Benchtop LCR meters generally offer more features than handheld such as programmable frequencies, better measurement accuracy to 0.01%, computer control and data collect for automated applications.
LCR meters are typically used to measure a range of parameters on magnetics, such as impedance, inductance and resistance This is achieved by applying a fixed voltage at a chosen frequency and then measuring a the actual voltage across the part under test b the actual current flowing through the part under test.
Similar to the number coding, first and second color bands represents the first and second digits of the value, third color band is the multiplier and fourth band is the tolerance. Therefore the value of inductor can be determined by reading the colors of inductor body and comparing them with color code chart.
Turn your multimeter dial to the lowest ohms setting, usually 20 or 200. Place the two probes on the atomizer your coil is in, one probe on the positive pin (the one in the middle of the 510 connection), and the other on the outside 510 threading, to get the total resistance of the coil in the atomizer.
A 3-phase Line Reactor is a set of three (3) coils (also known as windings, chokes or inductors) in one assembly. It is a series device, which means it is connected in the supply line such that all line current flows through the reactor, as shown below. Line Reactors are rated by % impedance, voltage and current.
3% impedance line reactors should be used to reduce power line transient voltages caused by capacitor switching, line notching, DC Bus over-voltage tripping and inverter over-current and over-voltage conditions. They improve the true input power factor and reduce cross-talk between drives.
DC line reactor is used to limit AC component on DC to a specified value. Filter reactor, also called DC smoothing reactor, is used at DC side of converter. The current in line reactor is direct current with AC component. It is used to limit the AC component on direct current to one specified value.
By inserting inductive reactance into the circuit, which is a high impedance to harmonic frequencies, line reactors reduce the amount of harmonics produced by a VFD system. For harmonic reduction purposes, you typically apply 5% impedance line reactors to the input of motor drives 20 hp and higher.
A line reactor is essentially an inductor—a coil of wire that forms a magnetic field as current flows through it. The magnetic field limits the rate of rise of the current, which reduces harmonics and helps avoid unnecessary tripping of the drive.
The main function of the reactor is to increase the short-circuit impedance and limit the short-circuit current, which is usually connected in series to the circuit of the outlet circuit breaker.
Input (line) reactors should be used in these circumstances:
The input line power is prone to have disturbances such as surges, spikes, transients, etc. The supply line power is very stiff (greater than 10 times the kVA rating of the connected VFD).Output (Load) Reactors
An output (load) reactor, on the other hand, is used to protect the motor if the wiring distance between the VFD and motor is very long. The drive generates a high frequency PWM three-phase output and noise spikes are generated on the leading edge of these signals.The formula which calculates the inductor voltage is V= Ldi/dt, where V is the voltage across the inductor, L is the inductance of the inductor, and di/dt is the derivative of the current flowing across the inductor.
Inductance is measured by applying a sinusoidal signal and then measuring the phase difference between the voltage wave form and current wave form. Connect the motor to a function generator or the such. Place a resistor in series between the motor and the function generator on the negative side.
Reactor An electromagnetic device, the primary purpose of which is to introduce inductive reactance into a circuit. Inductor A device consisting of one or more associated windings, with or without a magnetic core, for introducing inductance into an electric circuit.
In electronics, a choke is an inductor used to block higher-frequency while passing direct current (DC) and lower-frequencies of alternating current (AC) in an electrical circuit. The name comes from blocking—"choking"—high frequencies while passing low frequencies.
An inductor is a passive electronic component which is capable of storing electrical energy in the form of magnetic energy. Basically, it uses a conductor that is wound into a coil, and when electricity flows into the coil from the left to the right, this will generate a magnetic field in the clockwise direction.
Line choke or input choke is nothing but like a transformer. Its basic function is to protect drive from surge voltage or over voltage spikes in the Mains input supply to VFD. Ac drive works on switching principle hence it produces harmonics and disturbs mains Line.
A line reactor is an optional component that can be added to a drive system to protect the VFD and other devices from power surges and transients. A line reactor is essentially an inductor—a coil of wire that forms a magnetic field as current flows through it.
OUTPUT CHOKE (LOAD REACTOR)
Output choke help to reduce this peak voltage, and increase the rise time, to reduce the stress applied to the motor insulation and prevent damages. Output choke may be used to protect variable frequency drives and motors.Functions of Current Limiting Reactor
Current limiting reactor reduces the flow of short circuit current so as to protect the appliances from mechanical stress and overheating. It limits the fault current to flow into the healthy feeders or parts of the system, thereby avoiding the fault from spreading.An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. An inductor typically consists of an insulated wire wound into a coil around a core.
