TM 10-6640-239-13 1-29 g. Drain System.  The drain system consists of valving and piping required to route condensate and waste water from the sink and equipment to one of two deck drains located in the Supplemental Petroleum Laboratory.  The sink and most of the equipment in the laboratory compartment drain through the trailer floor to a quick- disconnect coupling and hose.  The equipment located in the mechanical room drains to the forward deck drain. The system is provided with a drain tank mounted under the sink which contains a submersible pump.  Waste water from the cloud, pour and freeze bath and sump pump tank overflow drain through the trailer floor (sink drain). h. Submersible Pump  (Sump Pump).  The sump pump, located under the sink, is constructed of high-impact, corrosion-resistant plastic with a built-in carrying handle.  A screened inlet prevents large solids from entering the pump.  It operates on 110V, 60 Hz, single-phase power supplied from A1CB14 located in MAIN POWER PANEL A1.  Return water from the electric still and evaporation loss bath drains into the sump pump tank and is returned to the water tank via the water return line and sump pump. i. Environmental Control Unit.  The four ECUs are identical.  Each has its own controller.  They operate on 208V, 60Hz, 3-phase power and are rated at 18,000 BTUs per hour when cooling and 12,000 BTUs per hour when heating.  During the purge cycle, ECU blowers pressurize the Supplemental Petroleum Laboratory to expel any explosive gases. j. Power Distribution Module.  The power distribution module is used when both the A-Lab and B-Lab are used together.  Internal components consists of the following:  3-phase current transformer, 3-phase current monitor, phase monitor, blackout relay, Lab-A contactor and Lab-B contactor.  Panel mounted components consists of: Lab-A power switch, Lab-B power switch, blackout switch, panel light switch, battle override switch, over current reset switch, a voltmeter, frequency meter, overcurrent indicator, out of phase indicator, two panel lights, Lab-A hour meter, and Lab-B hour meter.  External components consist of input power connector P1, external power connectors J1 and J2, and grounding lug.  3-phase power from an external generator set enters the power distribution module at connector P1.  The 3-phase power is then routed from connector P1 thru the current transformer to distribution blocks TB1-A, TB1-B, TB1-C, and TB1-NEUT.  From the distribution blocks 3-phase power is routed to Lab-A and Lab-B contactors.  The current monitor connected to the current transformer, monitors over-current conditions at all 3 phases.  During normal operation the internal relay is energized and phase A power from the phase monitor is routed to the Lab-A and Lab-B power switches to energize their respective contactor which routes the 3-phase power to connectors J1 and/or J2.  Once Lab-A and/or Lab-B power switches are closed the respective hour meter is energized.  If an over-current condition is detected the internal relay of the current monitor will de-energize removing power from Lab-A and Lab-B power switches and panel mounted over current indicator will illuminate.  Should an over-current exist, a panel mounted over current manual reset switch is used to reset the 3-phase current monitor.  If the power at the phase monitor is of the correct voltage and phase, the internal relay will energize and apply power to the normally open contacts of the internal relay of the 3-phase current monitor.  If the power at the phase monitor is not of the correct voltage and phase, it’s internal relay will not energize and panel mounted out of phase indicator will illuminate.  A battle override switch is provided to apply phase-A power to Lab-A and Lab-B power switches in the event of an over current, under voltage, or out of phase condition exists.  Panel light switch applies phase-A power to both panel lights.  A blackout light switch is provided to remove power from the panel lights and apply power to the blackout relay which in turns energizes and removes any possible power from the out of phase indicator or overcurrent indicator.