Leakage current concept
Leakage current is a common electrical leakage phenomenon in electrical equipment. This phenomenon causes energy loss and causes electric current to escape out of the device's case, leading to the risk of incidents such as electric shock, electric shock, or even fire.
What causes leakage current?
Old electrical equipment: When equipment is used for a long time, components will gradually wear out and become damaged, increasing the risk of electrical leakage.
Placing electrical equipment close to a wall or in a humid environment: Placing equipment near a wall or in a place with high humidity can easily cause them to become damp, thereby causing electric leakage.
Improper installation and repair: When components are installed incorrectly or in the wrong order, the product structure may change, leading to electrical leakage at connection or joint locations.
External influences: Mice, insects or other pests can bite off electrical wires or damage internal components of the device, causing electric current to leak.
What leakage current level is safe?
Regulations on safe leakage current may vary depending on the purpose and conditions of use.
For medical equipment, leakage current standards are strictly managed because of the risk of causing electric shock to the patient. Normally, the maximum allowable leakage current level in the medical field is 0.5mA. Exceeding this level may pose a high risk to the user.
For common electrical equipment, the safe leakage current level is in the range of 0.7-3.5mA. For handheld devices, the limit is 0.75mA, while other devices can accept a maximum of 3.5mA.
Instructions for checking equipment for electrical leakage
To check for electrical leakage, you will need electrical measuring devices such as an electrical tester, clamp meter or multimeter.
Use an electrical tester
An electrical tester is a tool that helps detect electrical leaks quickly. You just need to bring the pen into contact with areas or devices suspected of having electrical leaks. If the pen glows, it indicates a leak and needs to be addressed immediately. Electrical testers such as Hioki's 3481-20 or 3120 are good choices for performing this test.
Below are the steps to check electrical leakage with a multimeter:
- Step 1: Connect the meter to the probe.
- Step 2: Put the meter into current measurement mode.
- Step 3: Choose the appropriate scale. If you are unsure about the level of electrical leakage, start from the highest measuring range and gradually decrease to protect the meter from overload.
- Step 4: Place the probe at the point to be tested in the circuit and read the results displayed on the screen.
Check leakage current with clamp meter
Some popular clamp meter lines for this purpose such as Hioki 3280-10F and Hioki 3287 are options worth considering. Below are the steps to check leakage current with a clamp meter:
- Step 1: Disconnect the power source
Ensure safety by shutting off the circuit breaker or disconnecting the power supply. Always keep your hands dry and use protective gloves to limit risks.
- Step 2: Unplug the devices
Disconnect all electrical appliances in the test area such as televisions, refrigerators, microwaves, etc.
- Step 3: Prepare measuring equipment
Start the clamp meter, use the jaws to clamp the device around the wire to be measured. Make sure both jaws of the clamp meter are clean and completely closed when measuring to obtain accurate results.
- Step 4: Check ground leakage current
Perform measurements on single-phase circuits by clamping the jaws to the phase and neutral wires to detect ground leakage current. The device will display the level of leakage current present in the system.
Points to note when checking for electrical leaks
When you detect signs of electrical leakage, keep a safe distance and use protective measures to avoid risks. To perform the test safely, you need to note the following points:
- Keep distance and insulation: First, stay away from areas where there is suspected electrical leakage. Wear footwear with insulated soles to prevent electrical current from leaking to the ground, protecting you from the risk of electric shock.
- Use protective equipment: Wear rubber gloves and protective shoes before conducting the inspection. These items help you minimize the risk of exposure to electric current during operations.
- Avoid direct contact with the device: Do not touch the device directly with signs of electric leakage to avoid electric shock.
- Disconnect the power source before handling: To ensure maximum safety, disconnect the main power source before removing the problematic device from the system.
The above measures help ensure safety for inspectors and limit risks when handling electrical leaks in the system.
Tips for preventing and handling electrical leaks
To ensure safety, periodically use an electrical tester to check underground power lines. If a leak is detected, immediately disconnect the power source and carry out repairs to avoid danger.
In the event of a serious problem with underground wiring, such as a fire affecting the home's electrical system, you should consider switching to exposed wiring for easy monitoring. Or, if necessary, the wall can be drilled to replace damaged underground lines.
When installing a new electrical system, you should choose electrical wires with two layers of insulation to ensure safety. Make sure the installation process complies with technical standards, and use plastic pipes to cover the lines for protection. Plastic pipes should be highly durable, waterproof and have good strength.
Do not place the power outlet in places susceptible to moisture, as this may increase the risk of electrical leakage.
Conclude:
Above are my shares about the concept of leakage current, ways to check leakage current and notes when checking leakage current. You can refer to safe leakage current measuring devices at emin.vn, if If you have any questions, please contact us immediately for answers as soon as possible.
