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3 Steps To Perform Transformer Continuity Test

Performing a transformer continuity test can be hectic. You might have searched the whole internet but found out nothing. 

Can you perform a transformer continuity test? 

Yes, It is possible to perform a transformer continuity test. There are three steps to conduct the transformer continuity test. But before conducting the test, you need to consider a few things. Once finished, unplug the transformer first. Once done, you need to check it with a multimeter. Repeat the test afterward. 

But this isn’t enough. To perform the test, you have to know some basics. That’s why we’ve provided all the info you’ll need. 

Let’s dive into the details now, shall we? 

How Does A Transformer Work?

A transformer is a type of electric induction device. That only operates with alternating current. It is made up of a primary and secondary coil. 

There are many types of transformers available. But almost all of them work in a similar way. 

Each coil can be wrapped around a separate metallic core. Or both coils can be wrapped around the same core. The transformer functions the same manner either way. 

AC power applied to the input coil creates a magnetic field in the core. This causes a current to flow through the secondary coil. 

The voltage ratio between the primary and secondary coils is directly proportional. They are proportional to the number of coil windings. 

Because the input coil of a transformer has more turns than the output coil. The output voltage is less than the input voltage.

This is how electricity passes through the transformer. 

Why Conduct a Transformer Continuity Test?

A continuity test regulates whether or not there is a break in either of the coil wires. The primary aim of this test is to look for large differences. In windings as well as gaps in the connections. 

The resistance of transformer windings is measured to ensure that each circuit is properly wired. And that all connections are tight.

Things To Consider Before Conducting Transformer Continuity Test

There are some things you should check out before performing the test. This way you can conduct a safe and proper test. Plus checking these things doesn’t take much time. The duration is less than the time for retiling your shower.

These few important things are- 

Inspect The Transformer 

This is the most important step. While inspecting you might see the transformer is overheating or physically deformed. In that case, don’t try to test the transformer instead replace it. 

Overheating is a common reason for transformer failure.

Determine The Transformer’s Wiring

In this step, we will try to figure out the wiring of the transformer. The wiring of the transformer should be clearly labeled. You need to find out how the transformer is linked. 

For that, it is always better to obtain a schematic of the circuit. That contains the transformer.

The circuit schematic should be provided in the product information. And also the circuit manufacturer’s website.

You should also check whether the transformer is grounded or not. You usually have to ground main electrical panels, unlike transformers. It’s not mandatory but it’s safe.

Find Out The Transformer’s Inputs And Outputs

Now, firstly the transformer will be linked to the primary electrical coil. Then to its power supply. The secondary, the output, of the transformer, is connected to the second coil. This receives power from the circuit.

The voltage delivered to the primary coil should be labeled on both sides of the transformer. It should also be labeled in the schematic. 

The voltage generated by the second coil should be labeled in the same way.  

Regulate The Filtering Of The Output

The capacitors and diodes are commonly connected to the transformer secondary circuits. Because this way AC power can be converted from the output to DC power

The transformer conversion and output filtering information can be found in the schematic. Remember wherever the voltage is mentioned on the label. It has information on whether the transformer is AC or DC.

How To Perform The Transformer Continuity Test?

The below steps will help you to perform the transformer continuity test. Anyhow, you’ll just need a multimeter for the test. You can use the same multimeter that’s used for checking low voltage on one circuit or leg.  

Follow the below steps to perform the transformer continuity test.

Step 1: Unplug The Transformer 

First, unplug the transformer entirely. Set the multimeter to read resistance in ohms (Ω) afterward. 

Step 2: Check The Multimeter 

Check the reading by touching the meter. The dial will lead to the two input terminals of the primary coil. Which may be labeled H1 and H2. 

Infinite or a  very high resistance reading implies a circuit break. If you’re using a DMM, infinite resistance is represented on the screen. The letter will be OL or an open line. 

Step 3:  Repeat The Test 

Repeat the test on the output leads. These may be marked X1 and X2. Now, the transformer must be replaced if either coil registers infinite resistance or OL.

This is how you can conduct a transformer continuity test. 


Question: Is there resistance in transformers?

Answer: Transformers accomplish exactly what their name suggests. It converts voltages from one value to another. The term voltage is used rather than emf because transformers have internal resistance. 

Question: Is touching a transformer safe?

Answer: No, it’s not. Transformers are designed to shift voltage at specific ratios. Unless damaged, it can do so at any voltage level. This is why working on transformers can be extremely dangerous. It’s better to not touch the casing of a transformer. The fuses on the device’s high-voltage side as well. 

Question: What is the primary transformer protection?

Answer: A specialized protection, sometimes referred to as a thermal overload relay. It protects a transformer from overloading. The temperature of the transformer’s windings is stimulated by this type of protection. The simulation is based on the current measurement and the transformer’s thermal time constant.


We have provided all the information on the transformer continuity test. But if the steps seem too hard, do not hesitate to call an expert to help you.

Good luck!