Checking the Outlet (U.S. and Canada) AMS recommends using a dedicated outlet which can supply 15 to 20 amps per vendor. Using a volt meter set to AC VOLTS, check the voltage between the positive (smaller) lug entry and the ground lug entry (or center screw on two-lug outlets). The reading should be between 110 volts and 130 volts. Next, check the voltage between the negative (larger) lug entry and the ground. The reading should be 0 volts. If your results vary, contact a qualified electrician to correct the outlet wiring before plugging in the vendor. Abnormal voltage, reversed polarity or improper grounding may cause the vendor to malfunction or create hazardous conditions in the vendor, resulting in possible injury, damage to the vendor, or fire. The power cord is shipped in the hopper on the inside of the door. The cord is supplied with a standard NEMA 3-wire plug. If there are no 3-wire outlets available for powering the vendor, a grounding adapter may be used to convert a 2-wire outlet to accept the 3-wire plug. The adapter must have a ground tab or wire which must be fastened to the center screw of the outlet