ActronAir Indoor PCB AMIB Tri-Capacity is the factory-fitted indoor pcb amib tri-capacity for Tri-Capacity commercial split ducted systems, managing MODBUS 485 BMS integration, system ON/OFF, zone control, and compressor capacity management. A failed board causes loss of all BMS integration and building automation control -- fit the 100% Genuine ActronAir 2020-134B to restore factory system performance. Isolate power at mains before replacement -- live work on electrical components is dangerous and must only be performed by a qualified technician.