What this output module does in a Melsec Q rack
The QY80 is a 16-point transistor output module for the Melsec Q series PLC platform, switching 12 to 24 V DC loads at up to 0.5 A per point with a 4 A common limit. It draws 80 mA from the Q bus backplane for its internal logic, plus 20 mA at 24 V from the external supply that powers the output circuits. The module carries a 6.7 A fuse on the output side — that's the single-point failure protection for the common circuit, not a per-channel limit.
Output ratings that matter on the line
Each of the 16 transistor outputs sinks 0.5 A continuous, but the common terminal is rated 4 A total — so you can't drive all channels at full load simultaneously; the common limit governs the real-world output budget. Maximum voltage drop across the output transistor is 0.3 V at 0.5 A, which means the load sees at least 11.7 V on a 12 V supply rail — enough margin for most solenoid valves and indicator lamps. The external supply range is 12 to 24 V DC; the module's own 20 mA draw from that supply is negligible, but the 80 mA backplane consumption adds to the Q rack's total power budget.
Lifecycle and sourcing for the BOM line
It is quoted to order against your BOM quantity; current pricing and lead time are confirmed at RFQ through our sourcing desk.