I am a loss control / safety guy that works with several municipalities. I am curoius about the proper method to power a block heater from a receptacle protected by a ground fault circuit interrupter. The electrician tied the ground connection in the block heater to the heater frame and then opened the female end of an extension cord and disconnected the ground. He then plugged the extension cord into the GFCI receptacle and block heater. This may allow the circuit breaker to trip under a short circuit, but it may prevent the GFCI from tripping under a high resistance fault, which is what a GFCI is designed to do. Also, altering the extension cord to function other than as designed by the manufacturer may be exposing municipality to a citation and liability claim, specifically if that cord is mistakenly used in some other application.
To recap, if a block heater is properly installed and the ground fault circuit interrupter receptacle is of the correct amperage and properly installed, the system should work without having nuisance tripping. If there is nuisance tripping that is indicating a problem that should be resolved and not bypassed. Am I correct?