Subscribe Forever Tech Youtube Channel to get every latest video updates Assalam-O-Alakium friends I am Nadeem Robin and you are watching your own youtube channel forever tech so friends today in this video I am going to tell you that if switching relay is not in unit so what can be its result so what precautions should be made for it in my one video i told you that for what purpose switching relay is used so in that video which logics i told you today i will tell you there proofs today one PCB is with me so today i will show it to you and i will tell you that how much it is important to have switching relay in the unit as i told you that in indoor switching relay is not present this is normal because outdoor supply moves to indoor so not much problem occurs but if supply is from indoor so switching relay is also present here and as well as in outdoor so this is good practice and by this way safety may occurs now i will show you a PCB as you can see i am having this PCB we will remove other PCBs this PCB is of samsung DC inverter air conditioner's unit it is of 1 ton so not much problem occurs in this PCB but when problem occurs so what can be that problems so i will tell you about it as you can see if we open it we take it out from here as you can see this is filtering system no kind of switching relay is present here if you know it already than you should have alot information about it so here only filtering system is installed now its up side as it is known its back side here also no kind of switching relay is present now lets have a look inside it so i will open it as you can see here as well there is no kind of switching relay is present one relay is present here this relay is only for hot and cool to on its reverse valve beside it there is no kind of switching relay as you can see these are capacitors and heat sink is installed here so i will take out this heat sink and show what things are present here so you would be thinking that why they are making video again in switching relay because this kind of other PCB has come for repairing so i will show you it that what is its situation what were reasons behind it you have to listen it very carefully and have an attention on it and do not make mistakes so as you can see that here IPM, diode, IGPT and rectification IC is installed so you have seen these things here no kind of switching relay is installed but if i show you this is its indoor PCB here only one relay is installed as you can see switching relay is installed inside it as you can see this is working here and as you can see fan capacitor is installed here so now i will show you that due to which have give very impotance to switching relay that it is very safe and microcontroller control become very high on the PCB if here switching relay is not present so what happens so that i will show you so now here i will tell you that situation which have come here as you can see this is outdoor PCB which is approximately same model but there is difference in the model there is a bit difference in the PCB but they are in same category means both are of 1 ton PCBs and its IPM is badly damaged as you can see if we see IPM so its everything is damaged after this its low side is also badly damaged even in low side its microcontroller as you can see microcontroller is badly damaged as you can see and its repairing chances are zero and it can't be repair because it is impossible to find microcontroller the purpose to show you this what reasons can be behind them what reasons can be beside it company has made it very well not so much fault comes in it but today i got a burnt PCB so i thought to share this with you the first reason behind it can be if there is gas leakage in the unit so if gas is leaked and if any person charged the gas so he has not vaccum the system properly so this situation can occur because if there is air in the system so the air (oxygen) cause humidity in the system so when it cause humidity so that when it will pass through expansion valve and capillary so it will sometimes take the form of the water sometimes it will melt sometimes other fault can occur when it will go to compressor and after that touch to the electric wires of the comprassor so this kind of situation can occur and shortcircuit can occur and as you can see this kind of bad damage can occur comprassor can be burnt beside it damage of PCB is infront of you and the other situation can occur that if high voltages are occured here high voltagse have occured so this PCB can burn i thought that the main reason here is that due to switching relay is not present here the control of the microcontroller is very less in the PCB because indoor PCB has more control on it and as you can see there is no damage on indoor PCB and is totally fine and it seems as it is new and as you can see its situation is not fine as they both were taking with eachother through signals and when it told indoor to close the system till that it has damaged badly thats why there is this posibility switching relay is how much important that i am showing you here after that the next reason can be that is when it goes for repairing and at the time being if its heat sink is loosed loose means if its screws are lightly installed than it works but if air gap becomes more in it means that distance become more in it between IPM and heat sink than also there is chance present that PCB can be damaged so in today video i will give you this suggestion that whenever you repair PCB so properly install its heat sink if there are screws must install them because due to it damage chances are finished and after this the gas charge do it properly and must vaccum it and properly do the connections of electric and wiring how company has recommented do it like that than damage chances are less that this PCB get damage i hope that you may also liked this video so we will met in next video keep watching Forever Tech
