Sterlco Midsize - Manual (Page 10)

Page 10 Portable Hot Oil Temperature Control Units
Electrical System Controls
The electrical controls of your temperature control unit are specially engineered for
reliability, safety and simplicity of operation. The switches are clearly labeled as to their
function. Your temperature control unit has a system status board so you can evaluate the
status and performance of the unit at a glance. Pilot lights are provided to indicate key unit
functions.
An audible alarm is standard with your unit. The alarm will sound in the event of the
following conditions:
• motor overload
• safety thermostat trip (over temperature)
• low fluid pressure
• low fluid level
• high fluid level (optional)
Push the ALARM SILENCE button to silence the alarm. See Chapter 5 for more information
on control functions.
Electrical Panel and System Components
The pump motor and immersion heater operate on three-phase, 50/60 cycle, nominal voltage
with the control circuit at 115 V single phase. The control circuit voltage is provided by a
single phase machine tool transformer with primary fuse protection and a grounded
secondary. A main power disconnect is included as for ease of service. The electrical panel is
UL listed and complies with N.F.P.A. 79 provisions.
All components are IEC rated for long life and reduced maintenance. The heater elements are
branch fused, and protected from contactor welding by a separate primary voltage contactor.
The pump motor is controlled by a full voltage magnetic reversing starter, with fused branch
circuit overcurrent and thermal overload protection. Many additional features are available as
options.
A NEMA 12 enclosure is standard, with NEMA 4 available as an option.
Air Purge
Upon initial start-up and mold/process change-out, you’ll need to purge all air and water from
the system. The unit
has appropriate valving to ensure complete purging; procedures are
covered in Section 4 on Page 27.
!
WARNING
Failure to purge the system of air before heating
may result in serious injury or critical system and
equipment damage.
Make sure you properly purge the system of air
before starting the heater cycle.