LiftMaster SW470 SW490 S3 BOARD Manual - Page 18

18 Installation Electrical Power Connections CAUTION Make sure power is disconnected at the main power source and at the operator's electrical disconnect switch before proceeding. Secure all electrical power connections inside the power wiring compartment. Use the electrical wiring diagram supplied with this unit. All single phase operators will have - L1 (neutral), L2 (hot) and ground. All three phase operators will have - L1, L2, L3 and ground. It is very important that operator is properly grounded. IMPORTANT NOTE:On three phase operators the power connections must be properly phased. If they are phased wrong the gate operator will run backwards. To correct this situation, disconnect power a main power source and at the operator's electrical disconnect switch. Then, reverse any two of the three power leads. Figure 15 0 1 -0 6 6 5 F1 0 Doc 01-G0665 Rev C