A good rule of thumb is to avoid tampering with the coolant coils or compressor on your air conditioner, regardless of whether it is a small window unit or a central air conditioner. Working on any part of the air conditioner that is under pressure can lead to a refrigerant leak, which can damage the unit. Additionally, the pressurized refrigerant will freeze whatever it comes in contact with, including your skin. Let a professional work on the refrigerant lines and compressor of your air conditioner.
Window and wall air conditioners can safely be disconnected from their wall outlets. If your unit contains a clock or timer setting, you may lose any saved times and have to reset the clock, but the unit should not be damaged by disconnecting it. Ensure the unit is turned off and never pull the plug by the wire.
The air handler is the portion of a central air-conditioning unit that is typically installed in the attic. It is responsible for blowing indoor air across the refrigerant coils and disposing the accumulated heat and waste water. You can safely detach any of the ducts or condensation lines from the air handler. Always make sure the electricity to the air handler has been shut off at the circuit breaker before working on it.
The central air conditioner compressor and condenser is the unit located outside your home. This is the portion of the air-conditioning system that is responsible for exchanging the heat absorbed from the indoor air by the air handler. In order to detach any of the pressurized refrigerant lines, the refrigerant gas will need to be removed from the system and then replaced. This is not a do-it-yourself job and requires specific equipment to prevent gas loss. Dumping refrigerant gas into the air is damaging to the environment and is illegal in some municipalities.