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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I have a carrier synergy 2000 heat pump. It had been tripping

Customer Question

I have a carrier synergy 2000 heat pump. It had been tripping the breaker repeatedly so I replaced both the start and run capacitors and the unit worked great for the last couple of weeks... then, the heatpump stopped running altogether yesterday. I discovered that the start capacitor had leaked all over the place. I replaced it again, but the heat pump and fan will not start now at all! I am getting the 6-blinks of the LED telling me the capacitor pct limit is an issue... not sure where to go next... can you help?
Submitted: 2 years ago.
Category: HVAC
Expert:  Phil replied 2 years ago.
Hello,You will need a clamp around type amp meter to assist in this trouble shooting process...If the start capacitor is round and made of black plastic, the potential relay that cuts it out of the circuit 3 seconds after the start has failed. These are not common on todays units. If the capacitor is metal with a metal top, then it is a 'run capacitor' if that has swelled up and leaking, then it is likely due to electrical spikes from the utility company, those can also damage the printed circuit card. This is much more likely. None of this diagnosis is going to be easy, it is also not something that the majority of HVAC shops can handle.... it is likely an intermittent electrical spike problem, that might only show up for a few seconds every day or so.... so that when the tech arrives he will not see anything wrong.Look for a voltage rating on the capacitor, if it is 370 volts, we might try upgrading it to 440 volts. ----------Regarding the printed circuit card, tell me how many thermostat wires attach to it and what colors, and which terminals on the card those wires attach to, we can do some tests on that once I have that data..
Customer: replied 2 years ago.
black start capacitor, 370volts... I replaced it with a brand new one. both capacitors are new...
is it possible for me to send you a picture of the circuit card and inside of the unit...wouldn't that be easier?
Expert:  Phil replied 2 years ago.
Hello again, If you can send pictures of the printed circuit card, and a clear, well focused photo of the wiring diagram glued to the inside of the unit service panel, taken from straight on and well lit, that will indeed help. You will also need a clamp around type amp meter $25 at Harbor Freight, and $50 or so at a big box home repair type store. Use the paper clip icon to attach pictures. We can go from there. .
Customer: replied 2 years ago.
pictures attached...let me know if that gives you a good look at what you need to see, thanks...
Expert:  Phil replied 2 years ago.
Hello again,This is not going to be easy.Stress test the printed circuit card.Use a hair drier to slowly and gently warm the card to 120F (warm to the touch but not hot and not over140F)... if you get any change in behavior that means the card is bad...A micro crack has opened in the printed circuit at a solder joint, or inside its CPU in that case .... or a short circuit has developed as the card expanded when you heated it.Constant expansion and contraction as these electronics heat and during their duty cycles over the years is what wears these cards out.It is also a good idea to replug all of the connections in the unit,that burnishes any oxidized terminal connections and will sometimes solve the problem, especially at the printed circuit card and in any sensor molex connectors. Do that with the power off to the unit of course.These cards are also damaged by Electrical Spikes caused by power failures and lightning. These high voltage spikes can literally explode the fine 'wire' connections inside the chip. There is also a shunt type device, often printed on to the card that allows a high voltage spike to arc across to ground harmlessly, some of these can wear out after a few times and allow the high voltage spike into the rest of the card and the CPU micro-circuits. The high end printed circuit cards use a large capacitor like device, or several in parallel, to capture and release such surges, these do not wear out.There is about a 30% chance the printed circuit card is bad.. but it is far from conclusive at this point. Next you will need a clamp around type amp meter to check the amperage being drawn on each of the 3 wires connected to the compressor when it starts, and... the amperage being drawn through the black start capacitor when it starts. .