so you think your capacitor may be bad in this video we'll cover troubleshooting and replacing the capacitor in your AC unit so let's take care of our disclosure statement first electricity is your friend but it can kill you if you don't have some general knowledge of electricity get someone who does or get some advice from a trusted and knowledgeable friend and proceed with caution don't just go poking around in the unit especially with the power on and even with the power off some items such as capacitors store energy and need to be discharged before touching them at the very minimum watch this video all the way through and review the multimedia video before going poking around read and follow the multimeters safety precautions listed in the description of the YouTube page for the multimeter we'll be using today enough said ok let's get started let's assume that you are viewing this to learn a little bit about capacitors hopefully your AC unit is not on the fritz and you're not in some type of crisis or emergency situation if that's the case it might be time to call in a professional there are two types of capacitors we'll be dealing with today start capacitors and run capacitors start capacitors are typically round in nature and generally enclosed in plastic they are used to get a compressor started and are connected to the compressor start circuit and a potential relay they drop out of the circuit once the compressor gets started and are not necessary to keep the compressor running most compressors today don't even have a start capacitor in them to get them running however if your compressor is having a tough time starting it might be a good idea to have one installed these are also called hard start kids run capacitors are different in that they are designed to continually stay in electrical circuit and continually supply bursts of electrical energy to the compressor or fan motor to keep it running there are two types of run capacitors that we'll be dealing with a single capacitor and a dual capacitor they can be identified by the number of terminals on the top of the capacitor itself a single single capacitor we'll have two sets of terminals on top and it's designed to operate one component either a fan motor or compressor a dual capacitor will have three sets of terminals on the top and it's designed to operate both the fan motor and the compressor with one unit a dual capacitor is nothing more than two single capacitors built together into one shell so let's see what we're talking about we're going to use our multimeter to check our capacitor and see how it is faring first we're going to disconnect the power of the electrical unit so first we're going to discharge our capacitor here we're going to take a pair of pliers here and we're going to go across the two terminals from common to our fan terminal discharge it we're going to go from common to our compressor terminal capacitor and discharge that sometimes you may get a little snap electrical discharge other times you may get nothing in this case we didn't get anything now we're going to take the wires and remove the wires make sure that you have taken a picture of how the capacitor is wired and what wire goes where or at least jot down a little wiring diagram to let you know what wire goes where so we're going to pull our wires off here and now we're going to check the capacitance of this capacitor remember we've got two circuits hear the compressor circuit and the fan motor circuit on this capacitor so we're going to take our meter we're going to set it to capacitance sitting here we're going to take our leads go from the common terminal to the fan terminal and you see here that our capacitance on the fan circuit is 3.03 we know this capacitor was rated at a 3 micro farad for the fan side so we're right in line right there 3.0 3 now we're going to take the same thing go from the common terminal to the compressor terminal we're going to check it and here we're showing that the capacitor rating is 45.9 rating on this capacitor you remember it was rated at 50 so we're right at 10% in that area right there the capacitor is probably good but if you have any doubts at all to try it on the 10% side I would certainly have a capacitor as a standby to replace this but it sits right in that questionable area so we're going to put our flips so now we're going to remove the capacitor from the unit and just take a look at it remember we have already discharged our terminals here our discharge like capacitor so we don't need to be worried about getting shocked by the terminals here we can actually touch the terminals and it's not going to shock us we'll take and pull the capacitor out and you'll see here that the rating on the side of the capacitor is a 50 plus 3 UF 370 V so what that means is this is a 50 micro farad capacitor for the compressor unit and a 3 micro farad for the motor and it's rated at 370 boats so we've got a replacement capacitor here and you see that our terminals are marked we have our common terminal here on top marked with the see we have our fan terminal here marked fan and then we have our hermetic or compressor terminals here marked with a TR M so we're going to replace this thing back in the unit here put our screws back in to hold it securely in place and as we put the terminals back on I know the orange wires or our common leads here whoops see there I put them on wrong orange wire wire common terminals make sure we put them on the right terminals our compressor is the purple wire here and our fan motor is the brown wire so there we've got it all wired back in we're ready to start the unit back up alright so we've got the power back on the unit all we need to do now is go inside and start the thermostat and the unit should start up and run perfect and there we go our unit is right I hope this video has helped you a little in troubleshooting AC unit if it has please leave a comment below or share it on 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