The PLC controls the power section of the machine through 3-phase contactors, each equipped with thermal overload protection to safeguard the motors in the most efficient way. Residual Current Devices (RCDs) and automatic Low Voltage Detectors are also incorporated to provide unsurpassed levels of protection against electric shock and ensure continuous monitoring of the 3-phase supply. All other circuits are handled by switching relays. The PLC operates in tandem with a touch-screen control panel giving the technician complete control over all functions of the ST1, including manual ON/OFF, continuous cycle and even continuous 2nd ball cycle. Table/sweep manual operation is also provided.The PLC software is easily upgraded when program updates are made available by the Switch technical staff. Research and development is ongoing and, coupled with input from customers, Switch continually improves the most efficient and user-friendly complete bowling centre package available today.
The illuminated touch screen displays the status of all micro switches on the machine and also doubles as an alarm when required. Sweep and table motors have "Intelligent Protection"*, which eliminates the risk of damage to motors by continuously monitoring their operation through the PLC.

* Intelligent Protection: When the PLC recognizes that a motor should be running (the power circuit has been activated), and no signal is received from a micro switch relative to that motor within four seconds, the PLC will disconnect the power from the motor and send an alarm signal to the touch screen, which will flash in its alarm colour of red.

The touch screen will identify the motor that has created the alarm condition, so the technician will know where to intervene. "Icon" indicators are incorporated in the touch screen to track the status of the micro switches at all times. All power-control devices (3-phase contactors and switching relays) are accessible through a hinged cover to simplify fault detection and maintenance.

Advantages: in the event of machine malfunction, the technician can quickly determine whether the non responsive component- motor, solenoid, pit light, - is under tension or not. Troubleshooting is therefore simplified. The switching relays are identical and can be interchanged to assist with fault finding since they are mounted on sockets. Competitors' control boxes are closed and can give little or no help to the technician in determining the cause of any problems when they occur.

All power control devices can be quickly and easily changed by a competent technician.

Advantages: Control boxes can be repaired quickly by simple substitution of the control devices, virtually eliminating "return -to-base" repairs. Complete documentation is provided to every customer, and the pinspotter training programme will include a section on the electrical installation of the machine. The removal and replacement of the control box is facilitated by the use of plugs and sockets throughout. No hard wiring is used on the ST-1 for any connection.