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series 80 and series 90

series 10 is three wire,low voltage,two position. Two sets of contacts make in sequence to start; break in reverse sequence to stop. These controls were used before the advent of the mercury switch and snap acting contacts to prevent contolled devices from chattering. series 20 is three wire, low voltage two position. Makes one circuit to start, breaks it and makes a second circuit to stop. Series 40 is two wire, line voltage, two position. Makes circuit when switch is closed, breaks circuit when switch is open. Series 60 is three wire line or low voltage, single speed floating. Controlers are basically a SPDT switch. Series 70 is electronic. Series 80 is two wire , low voltage, two position. Series 90 is three wire, low voltage, proportional. Instead of a switch in the controller it has a potentiometer usually 135 ohm. bob


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