WEBSiemens WLETU776 Breaker Trip Unit. Siemens Breaker Trip Unit, Electronic LSI, Series: WL Series, 3 Poles, 200 to 5000 A, WLS/WLH/WLL/WLC Breaker Frame, For Use With: Low Voltage Power Circuit Breaker, Composite. Additional Description: SIEM-WLETU776 WL Trip Unit ETU776. Catalog Description: WL Trip Unit ETU776 ETU 776 L (S) (I) WITH GRAPHIC LCD.