Taylor-Wharton 24K w/ AutoTend - Manual (Page 38)

In addition to the above, an alarm condition may be triggered by an exceedingly long
fill mode.
The key to troubleshooting your CryoSorage system is to determine which component
in the system is the source of the problem. Determine if the problem is occurring in
any of the following subsystems: Supply Vessel, Transfer Line, Power Source,
Temperature, Level Sensing, Security, Lid Switch, Solenoid Valve, Control Display,
Alarm System, Communications. After determining which sub-system is having the
problem, isolate the problem further by performing sub-system tests. Once the
problem is isolated and defined, it will be easier to solve.
Controller Will Not Turn ON
1.
Press POWER button. If display is blank and dark go to next step.
2. Check all connections. Start with jacks at the foot of the controller. Pay special
attention to jacks labeled “POWER”. Wall transformer must be plugged into an
outlet providing AC voltage between 100 and 130 to deliver AC voltage 21 to 30
to the back of the freezer.
Indicates High Liquid Level
1.
Determine actual liquid level using a dip stick. Select MENU, LEVEL SENSING,
TEST LEVEL SENSORS. An “L” or “G” will indicate individual thermistor status.
“L” meaning that the thermistor is submerged in liquid and “G” indicates that the
thermistor is in cold Gas. Determine the pressure, and remaining liquid level in
the supply cylinder (15 to 22 psi). A fill solenoid valve that freezes (or sticks) open
will typically empty the supply cylinder. Replace solenoid valve if it has failed
even once. Confirm that Relief Valve has a pressure rating of 100psi.
2. Liquid level is sensed by thermistors located in a sensor tube. If the sensor tube
is blocked or iced at the top, the liquid level in the sensor tube may not rise and
fall at the same rate as the liquid level in the freezing chamber. Make sure the
sensor tube is not obstructed.
3. The pool of LN
2
can become turbulent during a fill. Bubbling and splashing can be
amplified by the rack arrangement. The deeper the pool, the more turbulent the
surface of the pool will be during a fill. The turbulence of the pool surface can
splash on the X-High thermistor and cause a false high alarm. Reduce the
splashing.
4. Confirm that sensor assembly is responding to changing liquid level with a dip-
test.
•
Mark the sensor assembly at top of tube to assure re-assembly.
• Close liquid supply valve at source.
•
Remove sensor assembly from sensor tube. DO NOT FORCE. Fill solenoid valve
should open and LOW LEVEL alarm should be activated.
• Select MENU, LEVEL SENSING, TEST LEVEL SENSORS. An “L” or “G” will
indicate individual thermistor status. (L = Liquid and G = Gas).
•
Dip each thermistor in succession into LN
2
Observe the controller display noting
that each thermistor changes from “G” to “L” as each is submerged. Response
time may vary.
•
Return to the main menu and submerge the START FILL THERMISTOR IN
TROUBLESHOOTING