Siemens 7SR224 - Current Protection: Under-Current (37); Figure 3.8-1 Logic Diagram: Undercurrent Detector (37)

(1) Description of Operation 7SR224
©2009 Siemens Protection Devices Limited Page 33 of 66
3.8 CURRENT PROTECTION: UNDER-CURRENT (37)
Two under-current elements are provided.
Each phase has an independent level detector and current-timing element. 37-n Setting sets the pick-
up current. An output is given after elapse of the 37-n Delay setting.
Operation of the under-current elements can be inhibited from:
Inhibit 37-n A binary or virtual input.
Figure 3.8-1 Logic Diagram: Undercurrent Detector (37)