Patent ID: 8371821

Claim:
A green waste water pump station for pumping from a well, said green waste water pump station comprising: a well into which waste water is fed from gravity pipelines; the well having a plurality of N submersible station pumps mounted at the bottom of the well, where N is greater than or equal to 3, the station pumps each having an outlet and the station pump outlets connecting to a common well discharge pipe; the station pumps being of equal horsepower whereby the horsepower is determined such that a single primary pump runs continuously after powering up without the water level dropping below the fully submerged pump height; a pump station set is assigned such that each of the N station pumps is successively numbered 1 to N; and a sequence controller for controlling the order of operation of the station pumps, the sequence controller including a power circuit associated with each of the station pumps, a timer having a timer total period and an indicator arm; and N control circuits each comprising a timer contactor, start and stop float switches, an overflow float switch and auxiliary relays; said N timer contactors being arranged to contact said indicator arm and dividing said timer total period into N equal operating periods equal to said timer total period/N; said sequence controller operating the station pumps by performing the following steps: Step 1 assigning a variable PrimaryPump=1 and a variable OperatingPeriod=1; and then beginning operation of the timer; and beginning operation of the timer; Step 2 assigning a pump station sequence with the primary pump being the station pump of said pump station set equal to PrimaryPump, a secondary pump being the station pump of said pump station set equal to PrimaryPump+1; with the successive pumps of the pump station sequence being numbered in order following the secondary pump, such that when ordering the successive pumps when station pump N is reached the next pump in the pump station sequence will be station pump number 1 ; the sequencing continuing until all N station pumps have been assigned to the pump station sequence, with the Nth pump in the pump station sequence being assigned as the backup/emergency pump; Step 3 operating the pumps as assigned in the pump station sequence in response to the water level in the well and the activation and deactivation of the start and stop float switches during said operating period until the timer indicator arm contacts the next of the N timer contactors; Step 4 assigning PrimaryPump=PrimaryPump+1, and OperatingPeriod=OperatingPeriod+1; if OperatingPeriod is greater than N then assigning PrimaryPump=1 and Operating Period=1; and Step 5 returning to step 2.