Sterlco SEU Series Economical Water TCU - Manual (Page 31)

WTR1-600 Chapter 5: Operation 31 of 42
1) Your Economical Series system operates with hot water under pressure. To
reduce the risk of scalding:
• Always wear work gloves and safety glasses when operating the unit.
• Never operate the unit with panels or shields removed.
• Pipe the relief valve to an open drain.
• Never install a fitting or hose that is rated less than 150 psig and 250°F
(1,034.25 kPa/10.34 bars and 121ºC).
2) To reduce the risk of electrical shock:
• All electrical installation and repairs should be done by a qualified
electrician.
• Ground the unit in accordance with electrical codes.
• Never attempt any repairs without first opening and locking out the main
disconnect.
• Never deactivate or neutralize any safety device.
5-4 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