1 positive 2 negative 3 ground

you don't have to have the ground for it to work.

what this is for is a safety device.

if you don't ground the appliance then it is possible (if it short circuits)

could catch on fire or cause damage.

then reason for the ground is if it does by chance short circuits, because it is grounded through the outlet to the panel, the breaker in the panel will just trip, cause no power to the appliance.


which in turns cause no damage and no fire.

so really it is just a safety measure they have because...if it does short circuits or there is a power surge (meaning to much power) it does damage the appliance or cause it to malfunction.

good luck and hope this helps