Cutout - Fluke 7009 User Manual

User's Guide
9.8
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band width from this point to 3 or 4 times wider. Table 3 lists typical propor-
tional band settings for optimum performance with a variety of fluids at se-
lected temperatures.
The proportional band adjustment may be accessed within the secondary menu.
Press "SET" and "EXIT" to enter the secondary menu and show the heater
power. Then press "SET" to access the proportional band.
Access heater power in secondary menu
12 Pct Heater power in percent
Access proportional band
Pb=0.101C Proportional band setting
To change the proportional band press "UP" or "DOWN".
New proportional band setting
Pb=0.060C
To accept the new setting and access the cutout set-point press "SET". Pressing
"EXIT" will exit the secondary menu ignoring any changes just made to the
proportional band value.
Accept the new proportional band setting

Cutout

As a protection against software or hardware fault, shorted heater triac, or user
error, the bath is equipped with an adjustable heater cutout device that will shut
off power to the heater if the bath temperature exceeds a set value. This protects
the heater and bath materials from excessive temperatures and, most impor-
tantly, protects the bath fluids from being heated beyond the safe operating
temperature preventing hazardous vaporization, breakdown, or ignition of the
liquid. The cutout temperature is programmable by the operator from the front
panel of the controller. It must always be set below the upper temperature limit
of the fluid and no more than 10 degrees above the upper temperature limit of
the bath.
If the cutout is activated because of excessive bath temperature then power to
the heater will be shut off and the bath will cool. The bath will cool until it
reaches a few degrees below the cutout set-point temperature. At this point the
action of the cutout is determined by the setting of the cutout mode parameter.
The cutout has two selectable modes — automatic reset or manual reset. If the
mode is set to automatic, then the cutout will automatically reset itself when the
bath temperature falls below the reset temperature allowing the bath to heat up