It is the first time your fridge stops cooling, or your oven stops heating, then you ask around to know if there was a way to diagnose the problems. You even go on search engines.
Most of the things you find on these search engines are testimonies on how others have used multimeters to figure out the errors with their electrical appliances, and how it made the repairs easier.
You’ve learned that a multimeter is a device that tests and diagnoses electrical appliances and components. So you know the instrument to use when you’re experiencing a situation like this.
But you get a multimeter from a neighbor or even go to an electrical store to get yours, and there seems to be a problem, you haven’t used one before, and you don’t know how.
There is no need to feel stuck even if you get hooked on the question, “how to use a multimeter to repair your appliance?”
We can help! We have a few tips on the tests you can carry out and how you can carry them out. Following these steps might highlight the first steps to take in getting your appliance back to work.
- Continuity Test
When you have a faulty appliance, it is common for it to have a continuity problem. Ok! If you haven’t known; continuity, to an electrical oriented mind, means electricity is passing through a component without restricted flow or resistance.
To test for continuity or flow of current through a part of your appliance, plug the two probes into your multimeter and connect them to the appliance, by touching one end of the lead to one terminal or the contact point of the device, and the second lead to the opposite terminal or the contact point.
You need to note that some parts have diodes and are one directional, so if you place the red and black probes wrongly on the opposite sides, you would have wrong or no reading.
If you have connected them rightly, now set the dial to continuity. When you get the reading of zero, then that part of the appliance is in suitable condition and electricity can flow through it.
If it doesn’t read zero, then the multimeter will display OL (open loop), or it will read towards one, then you know that part of your appliance has no continuity. One of the common faults of continuity is broken or damaged wires in your device.
- Resistance Test
Apart from the broken continuity of electricity, these currents could be slowed. To understand how the resistance test works with a multimeter, we have to first go into learning some information on resistance.
Resistance is another electrical term, as it is a direct opposite of continuity; it is the measure of the opposition to electric flow while the current is passing through a conductor in your appliance.
The resistance test measures how much current is lost during the flow through a circuit and resistance is measured in ohms. When trying to find the opposition or resistance, disconnect the component from the power source, so that you don’t ruin your multimeter.
It happens that for some parts of an appliance when you test them for continuity, they could read zero which means the current flows freely, and when you examine some other parts they could have some resistance. Even when they read differently, they can still work in good order, and this situation is normal, as these parts have different functions.
Continuity test works on a range of zero to one, and resistance could have several strengths or measures, so the resistance test is a little bit more complicated than the continuity test.
To measure the resistance of a part of an appliance, you would need to set the range on your multimeter to the standard resistance of that appliance part. After that, place the probes on either side of the device as you did for the continuity test.
The multimeter would provide a reading that would show higher or lower than the set amount in ohms. So to know the standard level of resistance of the part you are testing, you can consult the manufacturer’s troubleshooting manual of the appliance.
- Voltage Test
The voltage test is a well-known test, but checking voltage could be dangerous if you lack the proper training. You would need to see whether it is a direct current (DC) or an alternating current (AC).
Just like you did with the resistance testing, you would also need to manually set the range of the multimeter to the expected range, where it can read higher or lower. It is also necessary to ensure that the multimeter can handle the maximum expected voltage.
You can carry out this test to know the force of the electric pressure, as some parts of an appliance might be in an excellent condition but checking the voltage would make sure that it is mechanically sound.
When some appliances are broken, sometimes it is easy to detect the faulty part like a broken dryer belt or a corroded bake element. Although, for some other parts like a fuse or a switch, the actual damaged part is not always known, so that is where a multimeter comes in handy.
It is important to note that to perform either the resistance or voltage test; you should start with a continuity test so you can have it as a baseline for the other tests.
After learning all these, you now know how a multimeter could be an essential addition to your toolbox. You can begin to use your multimeter to perform tests and repairs on your switches, controllers, motors and all electrical machines with several parts like hairdryers, vacuum cleaners, electrical cords as well as other appliances.
A brief run down through the steps performed in using a multimeter is to
- First, disconnect the appliance from power source except you are testing a live circuit.
- Then plug the test lead into the multimeter.
- Select the function and connect the probes.
- Lastly, interpret the reading.