In this era where the use of electrical appliances has become a necessity, it is vital that you understand everything that revolves around them. One major thing to focus on when it comes to electrical products is conducting safety checks. Doing these safety checks allows you to determine when a specific appliance has an issue, thus allowing you to repair, or replace it on time, preventing any dangers. Here, we look at 5 major electrical safety checks that you should know about. So, keep reading to find out.
1. PAT Testing
PAT testing refers to the inspection of appliances to determine whether they are in the best condition for use. Most people conduct this test to help prevent electrical accidents at the workplace caused by faulty appliances. A complete PAT Test mostly involves using visual inspection, and some thorough check-up using special PAT devices.
After the PAT test, every checked device is always marked as passed or failed. That way, you or the company can determine whether those products should be repaired, or replaced. You can perform this test, or you can also find an electrician to do it at a scheduled time to ensure more accurate results.
Not every appliance needs to be tested. Here are the major product categories that should undergo PAT testing.
- Cables and chargers
- Portable devices
- Fixed machines
- Stationary appliances
- Hand-held devices
- IT appliances
2. EICR
An electrical inspection condition report (EICR) is a thorough and more in-depth inspection of your electrical systems, and installation. This test usually assesses your electrics competence by three categories. They are:
- C1- If your electrical system falls under this category after an EICR, then that means some danger exists, and it needs immediate attention
- C2- This category shows that your systems have a potential for causing danger, thus requiring you to act quickly
- C3- This indicates that your electrics have no significant issues. However, it also recommends that you improve your electrical system to avoid serious problems in the future.
3. High Voltage Test
This test, also known as dielectric voltage-withstand, or Hipot test is a non-destructive test done to help determine the effectiveness of a device’s insulation. This test is also done to determine whether a device qualifies for use at certain electrical conditions.
A high voltage test is usually applied to all devices for a given period to ensure that the insulation is not marginal. This test is always helpful, especially when it comes to finding crushed, or nicked insulation, terminal spacing issues, corrosive or conductive contaminants around your conductors, and tolerance errors inside cables.
Hipot testers mostly connect one side of supply to safety, and the other to your conductor that’s being tested. With supply connected like this, you can connect your conductor to two places: ground or high voltage. If you want to test over two contacts, then connect one to voltage, and the others to ground.
Testing a contact like this ensures that it is isolated from other contacts. If the insulation between the two contacts is enough, then applying a large voltage would cause some current to flow. Although a high voltage test is supposed to ensure that no current flows, the small flow is allowed in this case since no solid, or air insulation occurs. So, the vital current is the one produced by a partial discharge, and not one caused by capacitive coupling.
4. Ground Protection Test
Ground protection mostly consists of two primary test methods, namely Ground Bond test, and Ground Continuity test. Ground protection test is conducted to help prevent people from electrical hazards that might be caused when the unsuitable current has been created and flows to the earth.
The Ground Continuity test is done by inputting 1 Ampere DC to a power terminal to help confirm whether the resistance value between two ends is under 1Ω. Ground bond testing, on the other hand, is conducted by inputting about 25A to your power terminal, and checking if the resistance is under 100mΩ. Doing this test helps to ascertain that the earth continuity between the equipment, metal casing of your equipment, earth supply, and internal component connections is adequately earthed.
The resistance reading should be either 1 ohm, or less. If the reading is higher, then that means there’s a problem, and you must trace, and rectify it before proceeding. Also, remember to check if all connections, and your earth wires are secure, to reduce the chances of facing issues during the test.
Poor grounding is dangerous as it puts employees, and other people at risk, and also increases the chances of equipment failure. Therefore, companies should have adequately grounded electrical systems to ensure that there will be no dangers even in the cases of lightning strikes, or overvoltage as the current will travel to the earth safely.
5. Insulation Resistance Test
This test is done to help determine whether your insulation is good enough, and is usually divided into these steps:
- Charge
- Dwell
- Test
- Discharge
An insulation resistance test is the simplest to conduct. After making all the needed connections, apply your voltage for about a minute. During this time, your resistance either drops or remains steady. Large insulation systems mostly show a decrease while small systems remain stable. This happens because the absorptions and capacitive currents usually decrease to zero faster on smaller systems, compared to larger ones.
When doing this test, be very consistent. Why? Electrical insulations show changing behaviours during the test, thus forcing you to be extra keen. So, to evaluate different results on the same device, you have to do all the tests using one method, and under the same environment. The resistance readings might also keep changing because the electrical insulation materials will charge during the test. The unstable readings might be frustrating at first, but you get better at collecting the right one with time.
Above, are some of the most vital electrical safety checks that you should know about. Therefore, it is crucial that you also research thoroughly to help understand more about how they work. That way, you can conduct them accurately, allowing you to prevent any electrical dangers from occurring.
