National Electrical Code: The power cord & wall receptacle allowed by the National Electrical Code on A/C units is 250 volts or less. The max power cord length on A/C units for the 120-volt is 10’ & for the 208/240-volt is 6’. For safety reasons, Friedrich does not recommend the use of an extension cord. An extension cord may generate too much heat trying to carry the requested electrical load for the appliance and possibly cause a fire. This type of damage would not be covered under warranty.