Adjustable frequency pump control system

An adjustable frequency pump control system (AFPCS) that functions in combination with a plurality of system-external elements that include a power input, a circulation pump, and a chemical or filter control unit that produces a circulation pump-run signal and a backwash signal, said system comprising:

• a) an enclosure that is dimensioned to enclose all the elements that comprise said system, said enclosure having means for interfacing with the power input, the circulation pump and the chemical or filter control unit,
• b) an adjustable frequency drive (AFD) that is programmed during the start-up of said AFPCS with data that includes set points and switching sequences that meet a customer's requirements, said AFD having an input that is connected to the power input and an output consisting of a frequency-controlled, motor speed control signal that sets the speed of the circulation pump by adjusting the frequency of the motor speed control signal,
• c) a power supply having an input connected to the power input and an output consisting of a first voltage and a second voltage,
• d) a system mode selector switch having an input that is connected to the first voltage, and an output consisting of a selected mode signal comprising either:
• (1) a bypass mode,
• (2) a normal filtration mode,
• (3) a manual backwash mode,
• (4) a normal filtration plus mode,
• (5) an automatic mode, or
• (6) an automatic plus mode,
• e) a time clock having an input that is connected to the first voltage, and an output consisting of a mode timing signal,
• f) a pressure transducer that is enabled when the second voltage is applied, wherein said pressure transducer produces a line pressure signal,
• g) a program logic control (PLC) having a plurality inputs and an output, wherein the plurality of inputs are comprised of:
• (1) the selected mode signal that is applied from said system mode selector switch,
• (2) a mode timing signal that is applied from said time clock,
• (3) the circulation pump-run signal applied from the chemical or filter control unit (64),
• (4) the backwash signal applied from the chemical or filter control unit, and
• (5) the line pressure signal applied from said pressure transducer, wherein the output of said PLC is the frequency-set signal that is applied to said AFC, which in combination with said software, produces the frequency controlled motor speed signal that is ultimately utilized to control the speed of the circulation pump.

An adjustable frequency pump control system (AFPCS) that functions in combination with a plurality of system-external elements that include a three-phase power input (60), a circulation pump (62), and a chemical or filter control unit (64) that produces a circulation pump-run signal and a backwash signal, said system comprising:

• a) an enclosure (12) that is dimensioned to enclose all the elements that comprise said system, and having means for interfacing with the three-phase power input, the circulation pump and the chemical or filter control unit,
• b) a set of three circuit breakers (14), each having an input that is connected respectively to the three lead lines from the three-phase power input (60), wherein the output of said circuit breakers (14) is comprised of three output power leads (11), (13) and (15),
• c) a set of three line reactor filters (16), each having an input that is connected respectively to the three output lead lines (11), (13) and (15) from the outputs of said three circuit breakers (14), wherein the output of each said line reactor filter (16) is a filtered a-c voltage,
• d) an adjustable frequency drive (AFD) (18) that operates in combination with software (20) that is accessible via a keypad (22), said AFD (18) having an input that is applied the filtered a-c voltages from said line reactor filters (16), and a frequency-set signal (17), wherein said AFD has a memory that is programmed during the start-up of said AFPCS 10 with data that includes set points and switching sequences that meet a customer's requirements, wherein the output of said AFD is a motor contactor close signal (19) and a set of three frequency-controlled motor speed signals (21,23,25) that set the speed of the circulation pump (62) by controlling the frequency of the signals, wherein three motor speeds are available:
• (1) normal filtration speed,
• (2) backwash speed, and
• (3) plus speed,
• e) an AFD motor contactor (24) that, when closed by the application of the motor contactor close signal (19), passes the motor speed control signals from said AFD (18),
• f) a bypass contactor (26) having an input that is connected to the three output power leads (11,13,15) from said three circuit breakers (14), and an output that is connected in parallel across the output of said AFD motor contactor (24),
• g) a motor thermal overload (28) having an input connected to the outputs of said AFD motor contactor (22) and said bypass contactor (26), wherein the output of said motor thermal overload (28) is the set of motor speed control signals (21,23,25) that in combination with said AFD (18) produces a selected frequency-set signal that controls the speed the circulation pump (62),
• h) a power transformer (30) having a primary winding (30A) and a secondary winding (30B), wherein the primary winding is connected across the output power leads 11 and 15 applied from the output of said circuit breakers, wherein the secondary winding produces a stepped-down voltage,
• i) a system mode selector switch (32) having an input that is connected across the secondary winding of said power transformer (30), and an output consisting of a selected mode signal comprising either:
• (1) a bypass mode,
• (2) a normal filtration mode,
• (3) a manual backwash mode,
• (4) a normal filtration plus mode,
• (5) an automatic mode, and
• (6) an automatic plus mode,
• j) a d-c power supply (34) having an input that is connected across the secondary winding of said power transformer (30), and an output consisting of 24-volts d-c,
• k) a time clock (38) having an input that is connected across the secondary winding of said control transformer, and an output consisting of a mode timing signal (35),
• l) a fan (40) having an input that is connected across the secondary winding of said control transformer, wherein said cooling fan is positioned on said enclosure (12) to provide an optimum cooling airflow through said enclosure (12),
• m) a pressure transducer (36) that is enabled when the 24-volts d-c from said d-c power supply (34) is applied, wherein said pressure transducer produces a line pressure signal (37),
• n) a program logic control (PLC) (42) having six inputs and an output, wherein the six inputs are comprised of:
• (1) the stepped-down voltage applied from the secondary winding of said power transformer,
• (2) the select mode signal that is applied from said system mode selector switch (32),
• (3) a mode timing signal that is applied from the time clock (38),
• (4) the circulation pump-run signal (39) that is applied from the chemical or filter control unit (64),
• (5) the backwash signal (41) that is applied from the automatic chemical and filter control, and
• (6) the line pressure signal (37) that is applied from said pressure transducer (36), wherein the output of said PLC (42) is the frequency-set signal (17) that is applied to said AFC (18), which in combination with said software (20), produces the frequency-set signal that is ultimately utilized to control the speed of the circulation pump (62).