New unit just quit no compressor, no fan, breaker

Remove the access cover from the outside unit. Find the contactor. It is the part that has the high voltage incoming wires attached. There is a button/bar in the center of the contactor. Use a insulated screwdriver or a wood pencil and push the bar in. If the unit starts you will have to trace the low voltage circuit from the thermostat and air handler to the outside. 24 volts should be present at the low voltage contactor terminals via the defrost board. If you have 24 volts to the defrost board,turn off the outside power, remove the red low voltage wire from the defrost board then reattach it. The board may be tripped on a low voltage fault.
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