The only electrical input connections to the dryer are the 3-phase (3ø) power leads (L1, L2, L3, and sometimes neutral) and ground. Single-phase (1ø) power for the control circuit is done internally to the dryer. No single-phase (1ø) input connection is required on a 3-phase (3ø) dryer.
For gas and steam dryers manufactured for operation at 3-phase (3ø), the electrical connections are made at the power distribution block located in the service box at the rear, upper left corner of the dryer. The ground connection is made to the copper lug also provided in this box. To gain access to the service box contactor, the service box cover must be removed.