It is important to test the voltage of live cables because there can be a lot of power available to cause damage and even death. This test should be done with a voltage meter called a multimeter.
Multimeters are tools that allow you to know the voltage of a circuit, and in this way, you will know if there is power or not. It is so versatile that it will tell you whether the cables are live. You will also know the available voltage. This tool allows you to troubleshoot electrical problems, check switches, and outlets.
What does it mean to check the voltage of the live wires?
Knowing the live cables’ voltage allows you to know or determine the wattage difference in the cables. You will know the power difference between neutral wires and live wires or live and ground wires. Although the difference between a ground wire and a neutral wire should be 0. The wiring may be faulty and causes a difference in power.
Be aware that this type of work to measure live cables’ voltage can be dangerous and can cause serious injury or death. This work should be done if you have the necessary background knowledge to avoid serious problems.
How to set up a multimeter?
Before using a multimeter, it is important that you set it up correctly. A multimeter has the basic function of allowing current to flow through the meter to know the measurements. How to use a multimeter to test voltage of live wires? To configure your digital multimeter, you must follow the following steps:
- Turn the rotary dial to the section of the scale indicated or marked V with the alternating current symbol (~) next to it.
- Within this section, you will see various numbers that indicate the voltage level.
- You should set the dial to the lowest number. It should be higher than the voltage you expect on the wires. For example, in Europe UK, it is 230V; you must set your multimeter above that number.
- You should know that selecting the correct voltage level can increase the measurement’s pressure and increase the measurement.
- Some multimeters do not need these steps because they have an automatic range. If this is your case, just set the dial to V (~), and the meter will set the indicated range while doing the voltage measurement.
- You are now ready to use your multimeter. Remember that the black probe goes into the slot that is marked COM.
- You are now ready to use your multimeter.
How to use a multimeter to test the voltage of live leads?
How to use a multimeter to test voltage of live wires? If you want to use a multimeter to test the voltage of an active cable, you must follow these four steps:
Step 1: Security
As mentioned above, safety is very important when working with electricity. You must be very careful when it comes to CS 120 or 220 V. Remember not to touch a live wire with your bare hand; you must wear an insulating glove.
You should also make sure to switch the multimeter from DC to AC when you want to measure voltage in an AC circuit. You should also start your test with a higher current or voltage range.
Step 2: You need to set the parameter in voltage.
You need to set the knob to the voltage option. You can use your multimeter to measure current, voltage, and resistance. If you have a typical multimeter, you can measure a range between 200 V and 600 V DC or AC. You should use the V label and the straight line to measure the DC voltage in the voltage section. If you want to measure AC, you must use the V tag with ~.
Step 3: You need to connect the probes.
Multimeters have 2, 3, or more ports; they depend on the type of tool you have. You must plug the probes into the correct ports. Some classic multimeters come with three ports: COM, mAVΩ, and 10A; the latter should only be used with very high currents.
COM means common, and it is where the black probe goes; this probe always connects to a circuit ground or negative. The red probe goes into the mAVΩ port and allows measuring voltage, resistance, and current.
Step 4: Taking your actual reading
When you have the probes connected, it is time to continue with the actual reading. If you notice that a 0 appears on the screen, there is no current flowing through the cable; that is, there is no voltage in the cable.
You must know the meaning of the multimeter symbols to understand how they work. They are often very complex symbols and look like hieroglyphics, but you should know that they can easily read and understand symbols.
If you want to know how to use a multimeter to test voltage of live wires? You have to master the basics, and you will be an expert reading your multimeter.
- Button 1: The Hold button
It is located in the upper left corner of your voltage meter. This button locks the measurement after being pressed to remember the exact reading.
- Button 2: AC voltage
This symbol is identified by a V with a straight line or a V with a wavy line (~). This is the most common measurement to measure at your work or home; typically, it will measure between 100 and 240 volts.
- Button 3: Shift – Herz
It is used to measure the frequency of your equipment or circuit.
- Button 4: DC voltage
This button allows you to measure smaller circuits, batteries, indicator lights, etc. This button also has a V and three dashes. DC voltages must be less than 30 volts.
- Button 5: Continuity
It will emit a sound when it detects continuity in the 2 points. A symbol is a group of closed parentheses. It’s an easy way to check for an open or short circuit.
- Button 6: Direct current
It is the same as alternating current but direct. It looks like an A with three dashes – – -.
- Button 7: Current connector
It is a red jack with an A on it and should only measure current amps with red wire or clamp fittings.
- Button 8: Common connector
This is the black connector with COM on it. It is used for all tests and is used with the black wire.
- Button 9: Range button
This button can be found at the top of the multimeter, and its symbol is Lo / Hi. It is used to switch between the different ranges of meters.
- Button 10: Brightness indicator
Allows you to change the screen light; you can darken or brighten the screen for easier reading. The symbol is the sun.
- Button 11: Millivolts AC
mV with a wavy line across the top of the V is another symbol on your multimeter. It is used to test small circuits.
- Button 12: Change DC millivolts
It is the same as the previous one but with DC voltage.
- Button 13: Ohms
It allows you to determine if a fuse has blown or not. It allows you to measure the resistance. If OL appears, it means that the fuse is blown.
- Button 14: Diode test
It allows you to check whether your diodes are working or not. It has an arrow pointing to the right with a + sign next to it.
- Button 15: Capacitance change
This button looks like two letters T facing each other. Allows you to measure capacitance.
- Button 16: Alternating current
The symbol is an A with a wavy line above it. It is used with a clamp accessory to be able to measure alternating current. It lets you know how much charge an object uses.
- Button 17: Jack
It is used for all tests except the current. It is located on the right side of the multimeter. It can help you measure duty cycle, temperature, resistance, frequency, voltage, and much more.