T-354 5–21. Make sure that the start-stop switch (ST, on control panel) and circuit breakers CB-1 (in the control box andCB-2 (on the transformer) are in position “O” (OFF). Plug in and lock the 460VAC power plug at the recepta-cle on the transformer.2. Plug the 230VAC (black) cable into a de-energized 190/230VAC, 3-phase power source. Energize the powersource. Set circuit breakers CB-1 and CB2 to position “I” (ON). Close and secure control box door.Figure 5.1 Autotransformer5.3 ADJUST FRESH AIR MAKEUP VENTThe purpose of the fresh air makeup vent is to provideventilation for commodities that require fresh air circu-lation. The vent must be closed when transporting fro-zen foods.Air exchange depends on static pressure differential,which will vary depending on the container and how thecontainer is loaded.Units may be equipped with a vent position sensor(VPS). The VPS determines the position of the fresh airvent and sends data to the controller display.5.3.1 Upper Fresh Air Makeup VentTwo slots and a stop are designed into the disc for airflow adjustments. The first slot allows for a 0 to 30% airflow and the second slot allows for a 30 to 100% airflow.To adjust the percentage of air flow, loosen the wingnut and rotate the disc until the desired percentage ofair flow matches with the arrow. Tighten the wing nut.To clear the gap between the slots, loosen the wing nutuntil the disc clears the stop. Figure 5.2 gives airexchange values for an empty container. Higher valuescan be expected for a fully loaded container.Figure 5.2 Make Up Air Flow ChartDual Voltage ModularAutotransformerCircuit Breaker (CB-2) 230V460VAC Power Receptacle03060901201501802102400 10 20 30 40 50 60 70 80 90 100AIRFLOW(CMH) 1-PERCENT OPEN69NT40 FRESH AIR MAKEUPT-BAR2-3”T-BART-BARZERO EXTERNAL STATIC 50HZFor 60Hz operation multiply curves by 1.21/2”5/8”
