I have a question about NEC 210.8(B)(4). Is a LOCKING receptacles considered to be not accessible to the public and thius exempt from GFCI?
This has to do with the matter that the engine block heaters on diesel trucks leak too much current and trip out GFCIs. This has to do with salt water forcing its way into the wiring at 55 MPH. This is not a greater hazard than how if you do not ground a 480 volt motor it **WILL** have a nasty tingle voltage. As long as the truck is grounded there is not a problem.
If I do use a locking receptacle and power inlet there would also need to be a relay that disables the engine when it is plugged in. I have had 1 instance where a truck driver pulled straight blade receptacles right off of the wall! When somebody in concentrating on a task smart can be a relative term.
There are also ways to do continuous monitoring of the equipment grounds. This is 1 of the 4 safety techniques that are used in mines to make 1,100 volt and 3,300 volt extension cords that are as safe as breakfast food. The other 3 techniques are conductor shielding even for 120 volts, impedance grounding of the power source, and ground fault protection for equipment at both the branch circuit and feeder level. British coal mines have not had an electoction death since 1964 so they must be doing something right.
This has to do with the matter that the engine block heaters on diesel trucks leak too much current and trip out GFCIs. This has to do with salt water forcing its way into the wiring at 55 MPH. This is not a greater hazard than how if you do not ground a 480 volt motor it **WILL** have a nasty tingle voltage. As long as the truck is grounded there is not a problem.
If I do use a locking receptacle and power inlet there would also need to be a relay that disables the engine when it is plugged in. I have had 1 instance where a truck driver pulled straight blade receptacles right off of the wall! When somebody in concentrating on a task smart can be a relative term.
There are also ways to do continuous monitoring of the equipment grounds. This is 1 of the 4 safety techniques that are used in mines to make 1,100 volt and 3,300 volt extension cords that are as safe as breakfast food. The other 3 techniques are conductor shielding even for 120 volts, impedance grounding of the power source, and ground fault protection for equipment at both the branch circuit and feeder level. British coal mines have not had an electoction death since 1964 so they must be doing something right.
