Taylor-Wharton 24K w/ AutoTend - Manual (Page 21)

for open, a “G” for gas or an “L” for liquid. This is an easy means to tell if sensors are
in or out of liquid or if a new sensor assembly is needed (open sensors).
Set Sensors Offset
A sensor offset can be set through the menu system of the control (MENU, 2, 2). The
offset is used if the sensor assembly is raised off the floor of the freezer and the user
wants to read the actual liquid level on the display. An example of this would be a
STOP FILL setting of 23” and a START FILL setting of 20”. The 8 thermistor sensor
assembly would be set so that the bottom of the sensor assembly is raised 18” off the
floor of the freezer. The level would then read from 18” to 26”. The low level alarm
would be set at 19” since the START FILL is 20” and the high level alarm would be
24” since the STOP FILL is 23.” In operation, the liquid level would read between 20”
and 23.” The offset would be set to 18.” The control determines the liquid level by
adding the offset to the number of thermistors in LN
2
. The offset can be set from 0 to
40”.
Sensor Positions
The START FILL and STOP FILL sensor positions can be set through the menu
system of the control (MENU, 2, 3). START FILL and STOP FILL need to be set if an
8 thermistor sensor or the Freeze-Guard sensor is being used. If an offset is being
used, it is added to the sensor position to indicate the correct level of the sensor from
the floor of the freezer. The STOP FILL sensor must always be higher than the
START FILL sensor. Therefore, if START FILL is being increased where it would
pass the STOP FILL point, the STOP FILL is also increased so that it is always 1”
higher than START FILL. The converse is true for the STOP FILL when it is being
decreased. A four thermistor sensor assembly requires that the START FILL and
STOP FILL sensors be physically located at the correct position. Because of this the
menu selection for setting the START FILL and STOP FILL becomes inaccessible
when the 4 thermistor sensor is being used.
Sensor Type
The sensor type can be set through the menu system (MENU, 2, 4). The sensor type
selection should match the sensor type that is being used in the system. This is a 4
sensor, a 7 sensor (Freeze-Guard) or an 8 sensor array.
If the sensor assembly is unplugged and the main control is still on, the display will
indicate that a sensor error has occurred. In addition the level indicated would be 8”
on an 8 sensor assembly, 7” on a Freeze-Guard assembly or “High Alarm” on a 4
sensor assembly. This occurs because the control cannot differentiate between a
very high resistance (when a thermistor is in LN
2
) and an infinite resistance (when an
open circuit appears in the level sensing circuitry).
Alarms and Error Conditions
The KRYOS control tracks many different conditions in the freezer and therefore, has
a full complement of alarms associated with these different conditions. As alarms
occur, they cause an audible beep as well as a flashing red light. A remote alarm
relay is also triggered following a user designated period of time, after the error
condition occurs, if it is not corrected. In addition, the error condition is displayed on
the top line until the error condition is corrected.
When an error does occur, you may MUTE the audible alarm by pressing the desig-
nated button. The audible alarm will then be silent until activated by a new error