21. WIRING MISTAKE PREVENTION
 Improved quality of installation work through adoption of an “Connection error prevention” 
circuit which prevents wiring mistakes 
Connection errors with the control wires and the power supply wires will not only contribute to 
burning-out of the control circuit board, but can also cause large-scale working losses and 
affect reliability. If a circuit board with a “Connection error prevention” circuit is used, the relay 
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