shelolab SMO5HP-2, Руководство по эксплуатации и установке

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OPERATION
T
HEORY OF
O
PERATIONS
Heating
When powered, the SMO High Performance oven heats the oven chamber atmosphere to the current
constant temperature set point. The constant temperature set point, shown on the controller homepage,
can be adjusted by the end-user using the temperature arrow controls on the oven control panel. The oven
can also be programed with multi-step heating profile recipes. When launched, a profile overrides the
constant temperature set point. The oven resumes heating to the constant temperature set point only after
a profile terminates or is aborted.
The oven temperature controller stores 40 programmable heating profile recipe steps. The steps come
allocated to 4 ten-step profiles, but successive profiles may be combined to run sequentially as one profile.
Step types include timed-interval ramping (heating or cooling), soaking (constant temperature), and ending
states. Please see the Watlow EZ-Zone Profile Programing Guide shipped with this oven for more details.
Along with storing set points and profile steps, the temperature controller monitors the oven chamber air
temperature using a solid-state probe located in the airstream on the right wall of the chamber. When the
processor detects that the chamber temperature has dropped below the currently active temperature set
point, it pulses power to a heating element in a recirculation air duct space located above the oven
chamber. The processor employs proportional-integral-derivative analytical feedback-loop functions when
measuring and controlling the shelving temperature. PID-controlled heating pulse intensities and lengths
are proportional to the difference between the measured shelf temperature and the current set point. The
frequency of pulses is derived from the rate of change in that difference. The integral function slows the
rate of pulses when the temperature nears the set point to avoid overshooting.
SMOHP ovens rely on natural heat radiation for cooling.
When the oven is powered, the chamber air temperature cannot operate below the ambient room
temperature plus the internal waste heat of the oven. Waste heat is generated primarily by the operation of
the blower fan motor and the resulting air compression in the duct spaces. In practice, the lowest
operational chamber temperature is a15°C.
The heating rates given in unit specification section of this manual are for a 25°C environment. The
ambient temperature of the workspace around the oven affects its heating and cooling performance.
Air Circulation
The SMOHP continually circulates air internally while powered in order to maintain temperature uniformity
and stability in the oven chamber and to speed drying rates. Air is forced through vent holes on the right
side of the chamber, blows across the shelf space, and is then pulled into a duct that makes up the left
chamber wall. From there, the air is drawn upward into a heating duct by the action of the blower fan. The
oven is intended to be run as a closed air-cycle system.