The refrigerator does not works the whole time. It goes on and off during the cooling cycle, maintaining the ideal temperature inside the cabinet. For the compressor to be connected, the start relay is required, it is responsible for supplying energy to the unit. The relay is in the on/off operating command. But when a refrigerator needs repairing, how does one know if the start relay needs to be replaced?
How to test the start relay: One of the symptoms that the relay is damaged is when the refrigerator heats up and certain clicks can be heard. Before replacing it by a new start relay, do the test to discover if it really is the part which has a problem. Learn to test the start relay of the compressor: 1. Disconnect the refrigerator As you are going to work in the rear part, for your protection, the appliance should not be energized. This is a safety recommendation which must be followed when you are working with parts or equipment driven by electricity. 2. Remove the connectors of the relay Remove the protective cover of the compressor and remove the relay. With pliers, preferably needle-nose pliers, take the connector of the wire and remove the relay. Pay attention to not take the wire, but the connector. Note if there are signs of corrosion in the relay – if this is the case, opt to replace it. 3. Identify the model of the start relay There are different types of relays. The electrical unit of a refrigeration system is determined based on the voltage, frequency and operating envelope of the compressor. 4. Do the test with a multimeter
Electromechanical Relay EM
Step 1: With the relay in any position, check if there is continuity between terminals 1 and 2 of the relay. If there is not, change the relay.
Step 2: With the relay in the vertical position, coil of the relay upwards, check if there is continuity between terminals 1 and 3 of the relay. If there is not, change the relay and repeat step 1.
Step 3: With the relay in the vertical position, coil downwards, check if there is continuity between terminals 1 and 3. If there is, change the relay
Electromechanical Relay F, EG and PW
Step 1: With the relay in the vertical position, coil downwards, check if there is continuity between terminals 10 and 11 of the relay. If there is not, change the relay.
Step 2: With the relay in the vertical position, coil upwards, check if there is continuity between terminals 10 and 11 of the relay. If there is, change the relay and repeat step 1.
Step 1: With the aid of an ohmmeter, measure the ohmic resistance between terminals 2 and 3. At ambient temperature, the values should be near those presented in the list below:
Relay PTC– Relay PTC 8EA 1B1X – 2.8 to 5.2 Ω; – Relay PTC 7M4R7XXX / 8M4R7XXX / 8EA14CX– 3.8 to 5.6 Ω; – Relay PTC 8EA4BX / 8EA3BX / 8EA21CX – 3.5 to 6.5 Ω; – Relay PTC 8EA5BX – 14 to 26 Ω; – Relay PTC 7M220XXX / 8M220XXX / 8EA17CX – 17.6 to 26.4 Ω.
How to change the start relay As already mentioned, there are different types of relays. When it is necessary to make a change, do not try to improvise or make use of not recommended solutions. This can cause problems, such as the burn-out of the compressor. Always check out the technical sheet of the compressor (click here and check out the electronic catalog of Embraco). See the step-by-step to change the start relay: 1 – Remove the start relay After having located the relay, remove it paying great attention to the color and where the wire is connected. 2 – Fit the new relay With the new relay positioned, connect the correct wire in the output of the relay. The relay will always be in the two pins above and the thermal protector in the pin below. Fit the relay and press to fasten it in the compressor. 3 – Place the protective box again Fit the protective box and place the screws you have removed, to fasten it. You can now connect the refrigerator again!
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