5 Main Uses for Clamp Meters
Purpose 1: Measure three-phase three-wire loop current and three-phase four-wire neutral current
Clamp meters typically measure current in a single wire. When measuring the three-phase three-wire load current, if two wires are clamped at the same time, the indicated current value should be the current of the third wire.
The three-phase four-wire neutral wire current measurement method is the same as the three-phase three-wire circuit current measurement method, and the three-phase wires are clamped at the same time. The current value displayed at this time is the current value of the neutral line.
Application 2: clamp meter to measure small current
The clamp meter measures small current, even if the gear is adjusted to the minimum gear, the reading is still not very accurate. Therefore, it is possible to wrap a wire around the clamp arm and read the current value. Then divide the current reading by the number of turns to get the actual small current value.
Use three: Determine the name of the current in the line to determine whether the equipment is operating normally. It needs to be determined according to the current measured on site. So it's important to determine what current it 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 zero to find the power close to the level.
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 welding machine without a nameplate to determine the apparent power S
Estimation formula: The capacity of the 380 welding machine is equal to the no-load current I multiplied by 5.
data extension
How to measure resistance with clamp ammeter
Wire resistance measurement:
①Turn the switch to the electric resistance of the appropriate range.
② Keep the switch in the released state.
③The red test lead is connected to the "Ω" terminal, and the black test lead is connected to the "COM" terminal.
④The red and black test leads are respectively connected to the two ends of the wire under test. When measuring the resistance of the wire in use, the line should be disconnected from the power supply first, and the capacitance connected to the wire should be fully discharged before measurement.
Wire Continuity Test
①Turn the switch to 200Ω (or buzzer).
②The red and black test leads are respectively connected to the "Ω" end and "COM" end.
③ If the resistance between the red and black test leads is less than (50±25) Ω, the built-in buzzer will make a beep sound.
