scope:

Description of Driving Event:

During pre-operations for the 5A US Lab Closed Hatch Environmental Control & Life Support System/Thermal Control System (ECLSS/TCS) testing, a water separator fault occurred in the Common Cabin Air Assembly (CCAA). The inlet ORU was pulled and found to be wet inside. Three to four ounces of water were noted on the rack floor under the separator/heat exchanger. A small amount of water was found inside the separator but not enough to touch electronics. Water was also found in other areas (hydroflow fitting and coupler of the inlet hose and the inside of the inlet).

Root cause: The Test Procedure (TP) and Test Preparaton and Restoration Document (TP&RD) were not synchronized. The TP&RD placed a valve in series between the water separator and the GSE collection tank. The TP&RD also, appropriately, had the valve closed to keep water in the line after it was filled and before water separator was started. The TP did not open the valve before initaiation of water separator operations. The TP&RD & TP WERE NOT carefully reviewed for complete integration.