ActronAir Indoor Evaporator Fan Deck 9x9 T 3/4HP ECM combines variable-speed ECM motor technology with the T-mount shaft orientation for ESP Plus indoor units where the housing geometry requires the T-configuration layout. ECM fan decks on ESP Plus systems are integral to the Sound Reduction System -- a failed ECM deck removes the low-speed fan mode that reduces overnight noise levels and may generate a fault code. Isolate power at mains before replacement -- live work on fan assemblies is dangerous and must only be performed by a qualified technician.