Control panels designed for two or more pumps are fitted with an electronic device to start/stop one or more pumps automatically according to aspiration demand. The connecting device for the electronic circuit of all electronic control panels (i.e. all control panels marked by a final E, like C75/1E, C75/E etc.) must be completed with a peripheral P.B. unit to be placed next to the tip support. Tip supports and electropneumatic valves, which are necessary in all wet plants, are listed in the dry plants section at pages 25 and 27 of our export price list. Each suction machine can service a variable number of dental units depending on different parameters: diameter and length of the piping, number of bends, brand of the dental unit (requirements concerning aspiration can vary) therefore the number of dental units we suggest should not be considered as binding. The water feeding to the pumps PAL 28 and PAL 50 is made according to UNI EN 1717, November 2002, cat.5, protection unit A and B regulations (air break to drain). Water feedings to the pumps PAL 14 and PAL 38 has to be made according to UNI EN 1717, November 2002, cat. 5 , protection unit A and B regulations.