I HAVE A 10 YR OLD CARRIER HEAT PUMP.THE CONTACTOR POINTS WERE REPLACED TWO MONTHS AGO ,THEY ORIGINAL POINTS WERE PITTED AND NOT OPENING CAUSING COND. UNIT TO KEEP RUNNING.THE NEW CONTACTOR POINTS ARE DOING THE SAME THING AFTER TWO MONTHS. A/C TECH.DETERMINED THE COMP.WINDINGS ARE BAD CAUSING THE POINTS TO HEAT UP.WHAT DO YOU THINK I HAVE ACCES TO OHM AND MEGOMETER TESTERS. THANKS ALAN
An expert who has achieved level 2 by getting 100 points
An expert that got 10 achievements.
An expert that got 5 achievements.
An expert who has answered 500 questions.
Re: I HAVE A 10 YR OLD CARRIER HEAT PUMP.THE CONTACTOR...
First, check your compressor wires connections for loose or coroded, then clean them (file or sand them or just add oil to the ends connectors and go with a higher 24-va contactor instead of a 40-va, maybe a 80va 24-volt contactor.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
If you discover that your outdoor air conditioner and/or heat pump runs continuously even with your thermostat off and the indoor blower is off, the most probable cause is a stuck contactor. In most residential air conditioners / heat pumps, the contactor is the switch that allows voltage to your compressor and condensor fan motor; therefore, allowing them to run. The contactor allows line voltage (normally 208 - 240 volts) to pass through a set a contacts to your motor. The contacts pull in when the thermostat calls for Cooling and they "open" when the thermostat "satisfies". This is accomplished with the use of a low voltage coil. When 24 volts is applied to the coil, it creates a magnetic force that pulls the contactor in to close the contacts. When the 24 volts is removed from the coil, the magnetic force no longer exists.....a spring will force the contacts back "open" and stop the compressor and fan motor from running. The contactor is considered a wear-n-tear item as, eventually, the contacts will wear and begin to "pit". Eventually, they will either pit so severely, they will not allow enough voltage through them to operate the motors OR they may allow enough voltage and then overheat and weld themselves together. Often times you can lightly tap on the contactor and it will "free" the contacts and stop the motors. Unfortunately, once the contactor starts "sticking" it is highly likely it will stick again. Therefore, it is recommended that the contactor be replaced at first sign of sticking or when the contacts show signs of damage/overheating via a visual inspection.
you have 24 volt across both terminals of contactor coil? if not and condenser is still running then you have a stuck contactor. also this is a heat pump so you have 24v and common going to out side unit and rodents or dogs may have chewed up wire and causing a short making connection and this would have blew transformer. FYI installing a 3 amp car fuse(spade type) installed in line of 24v coming off transformer will protect transformer as well as other components. your T-Stat may be defective as well.
A couple of things can cause this;
the contactor points in the outdoor unit are pitted and sticking together, take the handle end of a screwdriver and tap the contactor, or turn off the breaker and see if the contactor points open. This problem can be frustrating as it can be hit and miss.
Even after this, if it is still running, disconnect the 2 thermostat wires, if it shuts off, you might have thermostat wires touching each other behind the thermostat.
Give this a try,
if your system is a heat pump you can switch to heat and see if coil outside gets cold while indoor blows warm air - then switch back to a/c - both coils should not be cold at the same time - low freon pressure / dirty coil / dirty filter / low air flow causes freezing
Probably the contactor, they have a coil that sometimes buzzes, after the contacts become pitted and no loger pull together like they are supposed to. It could also be a voltage problem from the transformer that is causing it, but I would bet on the contactor. Get it fixed quickly as a voltage drop across the contactor can be the demise of you compressor!
I'm not sure of the kilowatts. The 10 min on and 5 off is telling me there is to much heat by the thermostat or you house needs more insulation. The new compressor is designed for more efficient run time. The other thing is the unit to big for your house? It should run 10 -15 min when low humidity is in the house. Otherwise longer if its pretty warm inside.
No power to outside unit. Check to see if contactor on outside unit is pulled in. Most AC units inside have float switch. When the drain stops up it shuts off outside unit. Located in overflow or underneath unit. No Problem Rusty
A burned or pitted contactor will/can cause a unit to not run. Outside fan. Just thinking out loud. Start with low voltage check at t.stat then check outside low volt. Set t.stat to on. If fan engages at least your transformer is good. Next set calling for cool. Drop t.stat 68-70. If nothing happens go outside and with a screwdriver depress the contactor in. If fan and compressor kicks in change the contactor. If contactor is pulled in check outside fan. Remove the wires from the compressor and see if the fan will run . If it does you have eliminated start components as good. The compressor has to be check. It needs to be ohmed out. Turn off power at disconnect. Pull the cover on the compressor. Check between pins; then pins to ground. Open or infinite is good.Have you checked fuses. Like small 3-5 amp fuses