TM 10-6640-238-13 5-55 5-25.    ENVIRONMENTAL CONTROL UNIT. This task consists of: a.   Remove b.   Install INITIAL SET-UP Tools Required General Mechanics Tool Kit, (Appendix B, Section III, Item 1) Personnel Required Two (2) Materials/Parts Required Lockwashers, (12) General Safety Instructions WARNING ELECTRICAL SHOCK Before performing any maintenance actions on electrical equipment, ensure all electrical power has been turned off.  Failure to comply with this warning may result in serious injury or death. REMOVE 1. Remove Electrical Power. a. Position ECU remote control mode switch to OFF.  See Figure 5-21. b. Position Power Panel No. 2 circuit breakers A15CB1, A15CB2, A15CB3, or A15CB4 to OFF. 2.    Remove Environmental Control Unit (ECU). a. Disconnect two input power cables (1) from ECU (2). b. Disconnect drain hose (3) from adapter (4). c. Remove two adapters (4 and 5), elbow (6), and nipple (7) from ECU (2). d. Remove four bolts (8), washers (9), and eight isolation mounts (10). e. Remove 12 screws (11), lockwashers (12), and washers (13) securing flexible duct (14) to ECU (2).  Discard lockwashers. f. Remove quick release pin (15) from each side of ECU mounting platform to raise hold down bar (16). WARNING Serious  injury  to  personnel  or  damage  to  equipment  may  occur  unless  two  or more personnel are used to remove ECU because of weight and balance of units. g. Carefully move ECU (8) onto pallet or flat-bed truck. 3.    Remove Flexible Duct. a. Loosen four bolts (17) securing flexible duct (14) to Mod Lab and remove flexible duct.