Cut-Out - Fluke 7008 User Manual

7008
Users Guide

9.8 Cut-out

As a protection against software or hardware fault, shorted heater triac, or user
error, the bath is equipped with an adjustable heater cut-out 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
importantly, protects the bath fluids from being heated beyond the safe operating
temperature preventing hazardous vaporization, breakdown, or ignition of the
liquid. The cut-out 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 cut-out 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 cut-out set-point temperature. At this point the action of
the cut-out is determined by the setting of the cut-out mode parameter.
The cut-out has two selectable modes — automatic reset or manual reset. If the
mode is set to automatic, then the cut-out will automatically reset itself when the
bath temperature falls below the reset temperature allowing the bath to heat up
again. If the mode is set to manual, then the heater will remain disabled until the
user manually resets the cut-out.
The cut-out set-point may be accessed within the secondary menu. Press "SET"
and "EXIT" to enter the secondary menu and show the heater power. Then press
"SET" twice to access the cut-out set-point.
12
Pb=0.101C
CO= 110C
To change the cut-out set-point press "UP" or "DOWN".
CO=
9-10
+
Access heater power in secondary menu
Pct Heater power in percent
Access proportional band
Proportional band setting
Access cut-out set-point
Cut-out set-point
75C New cut-out set-point