Sterlco Midsize - Manual (Page 11)

Portable Hot Oil Temperature Control Units Page 11
Pressure Switch
A pressure switch is built into each unit to guard against heater damage. This feature prevents
the heater elements from being energized unless the pump is running and fluid is in the
system. After a preset time, the pump shuts down if the fluid pressure is not re-established.
The pressure switch is preset at the factory; do not tamper with it.
Safety Thermostat
The safety thermostat is a J-Thermocouple sensing, adjustable, fail-safe device located in the
heater tank. This is to guard against the unlikely event of “runaway” heating. If overheating
does occur, the safety thermostat shuts down the heater outputs and sounds an audible alarm.
A red pilot light on the status board also illuminates. The unit continues to pump fluid
through the system to prevent heater damage. Auxiliary factory installed alarms such as
beacons and klaxons are available as options.
All controller functions are locked out until the main supply power is disconnected.
Resetting the alarm condition is initiated by depressing the red pump stop button. The reset
button is located inside the electrical enclosure, mounted on the left wall of the enclosure. It
is imperative that a qualified maintenance technician determine and correct the cause of the
fault before resuming operation.
Reservoir Tank
A reservoir tank with sight gauge is standard; usable capacity is seven (7) gallons (26.5
liters). The tank permits thermal expansion of the heat transfer fluid, and provides make-up
fluid.
!
WARNING
The reservoir tank may cause serious injury if it
ruptures from not being properly vented.
Make sure that the reservoir tank is always
properly vented to prevent tank rupture.
The reservoir tank drain is extended beyond the base of the unit for ease of draining. Optional
ball valves are available to further simplify draining.