Sterlco SEU Series Economical Water TCU - Manual (Page 26)

WTR1-600 Chapter 4: Controls 26 of 42
Heaters
The specially designed 9 kW three-phase low watt density electrical immersion heater heats the
water, and the controller regulates the temperature. The standard heater has an incolloy sheath for
best heat transfer and low fouling properties.
Low watt density immersion heaters at 12 kW are available options for these models, depending
upon the heating needs of the process. All models are built to provide full heat as required by the
process and determined by the controller, providing more precise temperature control.
Solenoid Valves
Economical Series systems use rugged, industrial design solenoids with replaceable coils and/or
internal components. Depending on required cooling capacity, solenoid valves are available in
sizes ranging from
1 /
4
” to 3 /
4
”; 1 /
2
” x 9 /
16
” and 3 /
4
” x 3 /
4
” solenoid valves are slow-closing.
Water Hammer Arrestor (Shock Stop)- Optional
Shock waves from fast-operating solenoid valves may damage some process systems. For these
applications, a welded metal bellows-type shock stop with a pre-charged and sealed nitrogen
blanket can be installed in the cooling piping.
Pump Starter
Economical Series high quality IEC-rated pump motor starters are industrial grade motor controls
with overload protection and manual reset.
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 Economical Series unit uses high-quality IEC-rated industrial-grade electromechanical
contactors for heater controls.
Cooling
The controller automatically regulates cooling by opening and closing the solenoid valve. The
unit cools by removing the required amount of warm water from the system. This process
permits an equal amount of cool plant water to enter the system well ahead of the pump, allowing
it to blend with the system water. The water supply temperature governs the minimum operating
temperature of the unit.
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.