If you replace a compressor. Do you have to replace a capacitor as well? ?

Question

I got a compressor replaced for an AC unit in my rental property last year. This year the AC unit has been tripping off on its own from time to time. When I called in a service guy other than the one who replaced the compressor, he stated that the capacitor does not match the compressor capacity. He is asking me to replace the capacitor, buy a starter kit, and place in "solid state time guard". He is charging $160 labor and $100 for the parts. Does it make sense?

Answer 1

With the solid state unit in the system, it depends on what it does exactly. It may be a very good price for the work. If it was just the capacitor, I'd say it was overpriced.  Find out about the solid state unit. Understand it completely before you buy. Have it explained in one and 2 syllable words.

Answer 2

The first repair man should have put in a new start kit when the compressor was changed.  I'd get it changed out now if the old one is still in there.  It's a small price to pay instead of another new compressor which you will be buying if you don't get a new start kit in there.   If you ever have problems with a a/c unit that the compressor goes out, you really should just change the complete outside condensing unit. You will be better off in the long run and price is about the same.  If you would have done that last year. You would not have a serviceman back this year.

Answer 3

Yes.It must be changed with the compressor.If the PCS compressor motor has starting issues it might require a start capacitor as well,making it a CSCR compressor.The "time guard"might be a anti short cycle device and is very good to have installed as well.

The price you gave seems a little high but not too excessive and worth it.

A PSC motor only has a run cap and it is in the circuit at all times.

A CSCR motor has a run cap and it is also in the circuit at all times but it has a start cap in addition and it is only in the circuit for a fraction of a second and aids in the starting of the compressor motor.

Answer 4

HVAC Tech.:  The first tech should have replaced the capacitor when the compressor was replaced. There are so many compressors that have the same tonnage but different start loads so they require different capacitors. Even if they had the same rating, why go back with one you know has been stressed? Now you have a compressor that has been stressed by the wrong capacitor maybe he saved you $20.00 but he cut years off your new compressor. Find your warranty and keep it close, you will likely need it soon. In the future when you have a motor changed out make sure the capacitor is replaced along with it. The price is in line with what I'd charge for a new cap. and a hard start kit installed.

Answer 5

It does make sense.  Every compressor has it's own capacitor rewuirements.  If the first guy did not replace these components then there is a good chance that they are not rated for your particular compressor unless he used the exact same compressor and manufacturer model number as the oold one.  Even then the capacitor could have been the original problem and you really didn't need a new compressor in the first place.

Answer 6

No you don't need all that....when you change a compressor, it is a good idea to change the capacitor but its not required.

and as far as the starter kit $15-$20 nah not on a new compressor, those are for old hard to start units, the capacitor $6-$8 acts as a starter, like a beefed up battery. but they do have to match the compressor.

And the time guard...ive never heard of one being put on an outside unit. what are you guarding time from?  if the capacitor was right, this would not have happened.

Answer 7

Yes you needed a new capacitor. You should not need a start kit and if you have a digital thermostat you do not need a time delay installed. All digital t-stats have a integrated time delay. If it is a new compressor you do not need a start kit because, start kits are for older compressors which are drawing excessive amperage at start up.

He should have put the start kit on the old compressor, not the new one. He should have also installed a liquid line drier and he should have pulled a vacuum on the entire system after having installed the compressor and prior to charging it with freon. You also want a 20 degree differentail between supply and return air..