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# BACKWASH LOGIC MOD
PROBLEM:
OCCASIONALLY THE PLANT WILL RUN FOR THE 8 HR BACKWASH PERIOD, THEN GO INTO BACKWASH, RETURN TO FILTRATION, THEN SHUTDOWN NORMALLY ON TANK LEVEL.
WHEN THIS HAPPENS THE RECLAIM TANK HAS NOT HAD ENOUGH TIME TO DRAIN, WHICH CAUSES A HIGH LEVEL ALARM AND THE BACKWASH IS LOCKED OUT. ALL THIS IS NORMAL AND WORKS ACCORDING TO PLAN.
THE PROBLEM ARISES WHEN THE BACKWASH IS RE-ENABLED. THE ALARM SETS AND RESETS BY THE SAME FLOAT SWITCH, CAUSING THE BACKWASH TO RESTART WHEN THE TANK HAS ONLY DRAINED ABOUT 1 FOOT OF WATER.
THE HIGH LEVEL TRIPS AGAIN WITHIN A FEW SECONDS OF THE RESTART.
SOLUTIONS:
TIME DELAY FOR RECLAIM TANK ALARM RESET.
MINIMUM RUNTIME FOR FILTRATION BEFORE A BACKWASH IS ALLOWED.
WHEN THE PLANT GOES INTO FILTRATION MODE, DON'T BACKWASH WHEN THE PLANT SHUTS DOWN UNLESS IT HAS RAN FOR A MINIMUM OF 2 HOURS.
INITIATE NORMAL SHUTDOWN IF TANK LEVEL IS WITHIN X% OF THE STOP SET POINT
RETENTIVE TIMER FOR BACKWASH