AEC TCU Series Open Reservoir Water Temperature Control Units - Manual (Page 30)

Open Resevoir Water Temperature Control Units Page 31
Transformer
High quality industrial design transformers are specified to suit incoming voltage on the
application and provide 115 VAC control voltage. The 115 VAC circuit is protected by
primary fusing and secondary grounding.
Heater Contactor
Your TCU Series unit uses high-quality IEC-rated industrial-grade electromechanical
contactors for heater controls.
Cooling
With units equipped with the optional heat exchanger, the controller automatically regulates
cooling by opening and closing the solenoid valve or modulating valve. The unit cools by
automatically releasing cooling water through the shell of the specially designed tube bundle
heat exchanger in each zone. The process fluid, such as water, glycol, or other similar fluid, is
circulated through the tubes of the heat exchanger.
The plant water supply temperature governs the minimum operating
temperature of the unit.
Electricals
The pump motor and the immersion heater operate on three-phase 50/60 cycle nominal
voltages with the control circuit operating at 115V single phase. The control circuit voltage is
provided by a single phase machine tool transformer with a grounded secondary.
The 115V control circuit and controller outputs are fuse protected. The pump motor is
controlled by a full voltage magnetic non-reversing motor starter, with fused branch circuit
overcurrent and thermal overload protection.
Level Switches
This unit utilizes three conductive level rods inconjunction with a differential relay to control
the water level in the open reservoir. The three levels are low, mid, and high which control
the pump, the fill solenoid valve, and the controller operation, respectively.