| abstract |
A program controlled irrigation system (10) operates with two programs. Program A and Program B, for irrigating a plurality of zones. Selected zones are dedicated to the irrigation of grass, for example, under Program A while other zones are dedicated to the irrigation of shrubs, for example, under Program B. A total of six times for starting an irrigation cycle are available for both Programs A and B. Under program control, the six starting times can be allocated in any combination to Programs A and B. Further, starting times can be shifted readily between Programs A and B thereby providing flexibility to meet the changing demands in grass and shrub irrigation. Each zone is constantly monitored for overcurrent conditions wherein zone operation is terminated if the overcurrent of the particular zone is sustained beyond a set period. Also, if the current reaches an excessive level in a very short period, zone operation is terminated. Even though a single zone operation has been terminated as noted above, other zones can continue to operate unless the operation of two successive zones has been terminated whereupon the operation of the entire system 10 is terminated. |