Power supply to Nest Thermostat

[jaredmunster]

I recently bought a Nest to replace an older thermostat. I do not have a C wire at the thermostat so I purchased the Power Connector to install at the control panel. The issue I'm having is that the outdoor condenser unit is apparently controlled by the C terminal on the control panel.  I have tried connecting the Nest and leaving the condenser connected, which works to provide power to the thermostat until the condenser turns on, at which point the Nest triggers code N260 and disables wifi and other features until a "stable power source" is connected...  

Any thoughts, hivemind? (I've tried connecting the condenser to Y since that's cooling control, but that doesn't work.)

[CoolingWizard]

@jaredmunster, The Nest Power Adapter does not consume amps of current from the system. The HVAC system uses a 40 VA class 2 transformer.  This is more than adequate current to support the HVAC air handler, Condenser unit and the thermostat.  

If you also have a zone system or a Humidifier or dehumidifier also, this can reduce the available current of the transformer. 

Can you verify that you properly installed the power adapter for in the air handler? 

AC Cooling Wizard