Additional power supply, Busch-Welcome (2-wire system), system devices, additional power supply Additional power supply device for the Busch-Welcome system to increase the number of connectable indoor stations. For up to 45 consumption units. Nominal voltage: , +10 % / -10 % Output voltage: 28 V Nominal frequency: 50 Hz/60 Hz Nominal power: 28 W Protection class (device): IP 20 Temperature range (device): -5 °C to 45 °C Dimensions (H x W x D): 90 mm x 144 mm x 65 mm Division unit: 8