Command Pro Engineered SystemsUser Manual21 1421346.5 Installation Procedure -21R22Refer to Figure 8 and Figure 9.6.5.1 Power/Control WiringThe transfer switch is wired so that the crane’s Main Line Contactor (MLC) is controlled by the radio MLC andOPR relays when it is in the radio position and by the pendant controls when the switch is in the pendantposition. Refer to Figure 9 for typical input control wiring for 21R22 receivers.Transfer switch wiring is not required unless pendant operation is needed. The switch can normally be wiredwithout removing it from the receiver cabinet. Any unused switch poles can be used for additional isolation.!WARNINGBefore starting this installation, ensure that the crane power has been disconnected andthat all applicable safety precautions are followed.Use the following steps to install the wiring to the receiver board and/or control transfer switch.1. Disconnect the ‘hot’ input wire X1 from the pendant and connect it to terminal 9 of connector TB4on the receiver board (A).2. If pendant control of the 21R22 receiver installation is also desired, connect a wire from terminal 7of connector TB4 on the receiver board to the X1 input for the pendant (B).3. Install a wire (16 gauge) from terminal 1 (X2) of connector TB4 to the ‘neutral’ wire from the CraneControl Power source (C).4. Install a wire (16 gauge) from terminal 4 (MLC) of connector TB4 to the main line contactor. Thiswire will provide a continuous voltage to the ML Coil when the radio is on (D).Review the steps above to ensure the accuracy of the wiring before applying power to the installation. Go to21R14A Installation Testing and perform installation testing.