OPERATION
The conduit is permanently secured and the rear cover installed, apply power to the
control system to test the oven's components. Then run the oven up to 200F to verify
proper operation.
CAUTION: Do not run up to maximum operating temperature until the control
thermocouple has been positioned properly. Its current location may allow the oven to
exceed operating range and cause damage to the elements, the load train and/or your
specimen.
OPERATING CONTROLS
1.
The main circuit breaker is located at the rear of the control cabinet. When the
circuit breaker is in the off position, all power is removed from the oven. The
control cabinet should not be positioned such that it is difficult to operate the
disconnecting device.
2.
The control power switch is located on the front of the control cabinet. This
switch must be in the on position for the oven to operate.
3.
The light switch is located on the front of the control cabinet and is used to
control the interior light.
4.
The reset switch is located on the front of the control cabinet. It is used to reset
the high limit controller should the chamber temperature exceed the limit setting.
5.
The high limit controller is located on the front of the control cabinet and is used
to protect the chamber from excess temperature. The high limit backs up the
main temperature controller. If the set point is exceeded, an alarm message will
be flashed on the display. After the temperature has returned to normal, push
the reset switch.
CONTROL THERMOCOUPLE POSITIONING
The final position of the control thermocouple is determined by your requirements. This
may be determined by a trial and error process. It is recommended to have an
additional thermocouple and recorder for the test. A flexible thermocouple has been
provided for the control sensor.
1.
Position the monitoring thermocouple on the specimen or in the air near the
specimen. Thermocouple response time is dependent on the location and load.
2.
Position the control thermocouple in the air exhaust, mark this location A. This
will provide the slowest response in the system and the specimen may never see
the control temperature. This initial test will ensure that the exhaust temperature
will never be above the maximum for the oven.
3.
If the specimen does not reach operating temperature, save the information.
Now reposition the control thermocouple between the exhaust and inlet, mark
this one B.
4.
Conduct the test again and compare the results with the first run. If the specimen
reached temperature and the tuning for the controller is satisfactory, you may
either stop or reposition the thermocouple at another location of your choice to
see if any further improvement can be made.
You may have to repeat the test several times before the results meet your
specifications. It is difficult to position the control thermocouple at the factory due to the
limited information on the exact load being used.