5 Main Uses of Clamp Meters
Purpose 1: Measure the current of three-phase three-wire circuit and the current of three-phase four-wire neutral wire
Clamp meters generally measure the current of a single wire. If two wires are clamped in at the same time when measuring the current of a three-phase three-wire load, the indicated current value should be the current of the third wire.
The method of measuring the current of the three-phase four-wire neutral line is the same as measuring the current of the three-phase three-wire circuit. At the same time, the three phase lines are clamped, and the current value indicated at this time is the current value of the neutral line.
Application 2: Clamp meter to measure small current
Clamp meters measure small currents. Even if the gear is adjusted to the smallest gear, the readings are still not very accurate. Therefore, a wire can be wound around the arm of the clamp and the current value can be read. Then divide the current reading by the number of turns, which is the actual small current value.
Purpose 3: Determine the name of the current in the line
Judging whether the equipment is in normal operation needs to be determined based on the current measured on site, so it is important to determine what the current is.
Purpose 4: Measure the no-load current of a motor without a nameplate to determine the rated power
Estimation formula: Divide the no-load current by 0.8, and get the power close to the rating.
The steps are as follows: Measure the no-load current value I of the motor, according to the empirical formula: p=I/0.8
Purpose 5: Measure the no-load current of a 380V electric welding machine without a nameplate to judge the apparent power S
Estimate formula: The capacity of the 380 welding machine is equal to the no-load current I multiplied by 5.
The steps are as follows: Measure the no-load current value I of the electric welding machine, according to the empirical formula: p=5I
