L, N

AC 230 V power supply, mains and neutral

Q1

Output, fan speed 1, AC 230 V

Q2

Output, fan speed 2, AC 230 V

Q3

Output, fan speed 3, AC 230 V

Y1

Output “Valve”, AC 230 V (NO), SPST

Y2

Output “Valve”, AC 230 V (NO), SPST

X1

Multi-functional input for temperature sensor (e.g. QAH11.1) or potential-free switch (keycard)

M

Measuring neutral for sensor and switch

MB+

RS485 Modbus connection

MB-

RS485 Modbus connection

REF

RS485 signal/common ground (differential common)