Clamp meter how to use_clamp meter use method
Clamp meter how to use_clamp meter use
Clamp meters measure current by determining the magnetic field around a current-carrying conductor. There is essentially no other practical way to measure current in electrical wiring systems. It is impractical to disconnect these circuits to make a series circuit measurement, and even your career could be in jeopardy if you inadvertently disconnect some critical loads. Measurements are usually made at the switchboard and involve measuring the loads and balancing on the three-phase feeder. In the presence of a large number of harmonic loads, centreline measurements must also be made at the switchboard. Current measurements can also be taken to diagnose motor conditions.
In addition to these basic measurements, which are specially designed for clamp meters, modern digital shaped clamp meters also have voltage and resistance measurements. This means that most common everyday measurements can be made using a single clamp meter. If an electrician can only carry one test tool on the job, it makes sense to choose to take his clamp meter with him.
And, the clamp meter should be a true RMS type. The alternative is to use an average-response clamp meter, which is less expensive but does not accurately measure current. As long as there is an electronic load on the circuit ( computers, televisions, lighting fixtures, motor drives, etc.), the measurements of an average response meter may be inaccurate. The larger the electronic load, the greater the inaccuracy. A true RMS clamp meter will always give accurate results (assuming, of course, that you keep it calibrated). Therefore, unless you can safely say that you will not encounter this type of load, you will want to use a true RMS clamp meter. In this way, you are thinking about the work to be carried out rather than the test tool itself. Especially in commercial building construction, it is important to use a true RMS clamp meter that measures accurately.
Using Clamp Meters in Residential Applications
For residential facility electricians, a clamp meter is an essential tool used to make measurements of loads on individual branch circuits at the switchboard. While a spot check of the current is often sufficient, sometimes this check will not provide a complete picture as the loads are switched on and off and go through a number of cycles etc. Voltage in an electrical system should be stable, but current varies widely
To check for peak or worst case loads on a circuit, use a clamp meter with a min/max function designed to measure high currents that are present for longer than 100 ms or about 8 cycles. These currents can result in intermittent overload conditions that can cause annoying
stripping of circuit breakers.
Measurements are made on the load side of the circuit breaker or fuse. The circuit breaker will break the circuit in the event of an accidental short. This is especially important for any type of direct contact voltage measurement. Even if the jaws of the clamp meter are insulated and thus have a level of protection not available for direct contact voltage measurements, caution is still necessary.
A common problem in electrical work in residential facilities is trying to correspond electrical outlets to circuit breakers. Clamp meters are very useful in identifying which circuit a particular outlet is located on. Begin by obtaining a baseline reading of the existing current of the circuit at the electrical panel. Then, place the clamp meter in min/max mode. Go to the socket in question, plug in a load (a hairdryer would be ideal) and switch it on for a minute or two. Check that the clamp meter's maximum current reading has not changed. A hairdryer will usually draw 10-13 A, so there should be a perceptible difference. If the readings are the same, you are not using the correct circuit breaker.
