AEC Econo-Cool Chillers - Manual (Page 42)

AEC Water Temperature Control Units Page 41
5-5 Sequence of Operation
The simplicity of design and the highly engineered controller make this unit almost
self-operating. The
ON/OFF and VENT switches and the temperature controller buttons
are all that is required to operate this unit.
After you complete all connections, turn the water supply
ON , then turn control power
ON . The unit automatically vents for a preset time of one (1) minute. If you need
additional vent time, press the VENT button on the control panel.
As the water comes in the water supply line, the water must enter the pump, up through
the tank and out through the
TO PROCESS line, through the process, back through the
FROM PROCESS line, and through the solenoid line and out the drain line.
At this time, watching the drain for bubbles or erratic flow will indicate whether or not
the system has been properly vented. If a steady stream flows from the drain line, it is
certain that all the air is out of the system.
; TCU systems provide temperature control on processes by
directly heating the process water and injecting cooling water
into the process water.
; When the unit is energized, the pump starts and a one minute
vent sequence opens the cooling/vent valve to remove any air
trapped in the process piping.
; If the cooling water supply pressure is insufficient, the low
cooling water pressure cutout switch (set at 16 psig, 10 psig
differential [110.32 kPa/1.10 bars, 68.95 kPa/0.69 bars
differential]) opens. You need at least 16 psig (110.32
kPa/1.10 bars) for the best cooling capacity and to prevent
water boiling in the process circuit at high temperatures,
particularly at the pump suction.
; After venting, the microprocessor controller monitors the
TO
PROCESS probe, cycling open the cooling/vent valve to
discharge warm water or energizing the immersion heater to
maintain the process set temperature.