TM 10-6640-215-13 2-7.  ASSEMBLY AND PREPARATION FOR USE - continued. (9) Place driver/puller and driver/puller rod in storage box. (10) Slide grounding cable clamp over grounding rod. (11) Attach grounding cable to grounding rod with grounding clamp. (12) Attach grounding cable to grounding lug in power input panel.  (Refer to Figure 2-17.) f. Petroleum Laboratory Electrical Startup and Purge Cycle.  The following procedure is used to apply power to the Petroleum Iaboratory. WARNING Do  not  attempt  to  enter  the  Petroleum  Laboratory  during  start  up  until automatic     purge     cycle     (5     minutes)     is     completed.          Dangerous combustible  gases  or  vapors  may  be  present  which  could  ignite  and cause death or serious injury. (1) Unlatch and open the two PURGE INTAKE and the two PURGE  EXHAUST doors. (2) Unlatch and open the gum bath/fume hood exhaust door. (3) Roll up and secure the four ECU canvas covers in the up position. NOTE The main power input cable is stored in the roadside storage box. (4) Remove the main power input cable from the storage box. CAUTION Be  sure  that  main  power  cable  leads  are  properly  connected  to  the generator   set   to   prevent   damage   to   the   generator   set   or   laboratory electrical system. (5) Attach main power cable leads to the generator set as follows: Black wire - phase A (L1); Blue wire - phase B (L2); Red wire - phase C (L3); White wire - Neutral (N); Green wire - Ground (Gnd). (6) Remove protective cap from main power cable connector (Figure 2-17) at the power input panel. (7) Firmly connect the main power input cable to the cable connector. NOTE When power is applied to the Petroleum Laboratory, an air purge cycle utilizing  the  ECUs  blowers  to  pressurize  the  laboratory  and  expel  any accumulation of gases is automatically initiated.  The cycle will last for approximately   5   minutes.      During   the   purge   cycle,   all   the   normal electrical circuits within the petroleum laboratory are disabled. 2-45