Never disconnect wires while the device is powered. Turn off the main switch, then remove leads.
For a detailed look, you can view the QDB-2A Usage Instructions (Scribd) or QDB-2A User Manual (Scribd) . qdb-2a manual pdf
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: Maximum drive current up to 3A for PWM and 2.5A for general power out. Voltage Output : Adjustable (VADJ) from 1.25V to 14.5V. Basic Operating Steps Power Connection : Connect the tool to an external 12V or 24V power supply. Select Mode Never disconnect wires while the device is powered