ActronAir Indoor Evaporator Fan Blower 10x10 S 1HP ECM is the highest-output single-blower ECM assembly in the 10x10 range, suited to large Classic Series and ESP Plus indoor units where 1HP variable-speed performance provides the static pressure capability needed for complex multi-zone duct layouts. Unlike AC motor blowers, this ECM assembly receives speed commands from the indoor PCB -- if the blower runs at full speed regardless of system mode, the fault typically lies with PCB communication rather than the blower itself. Isolate power at mains before replacement -- live work on fan assemblies is dangerous and must only be performed by a qualified technician.