Taylor-Wharton KRYOS Controller - Manual (Page 33)

31
KRYOS
Indicates High Liquid Level
1. Determine actual liquid level using a dipstick. 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.
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.
t Mark the sensor assembly at top of tube to assure re-assembly.
t Close liquid supply valve at source.
t Remove sensor assembly from sensor tube. DO NOT FORCE. Fill solenoid
valve should open and LOW LEVEL alarm should be activated.
t Select MENU, LEVEL SENSING, TEST LEVEL SENSORS. An “L” or “G” will
indicate individual thermistor status (L = Liquid and G = Gas).
t 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.
t Return to the main menu and submerge the START FILL THERMISTOR IN
LIQUID. Note that the low level alarm ceases, fill solenoid valve is still open.
Control is flashing FILLING.
t Manually press STOP button and note that the fill solenoid valve closes.
t Press FILL button to re-open fill solenoid valve.
t Continue to lower the sensor until the STOP FILL thermistor is immersed in
the LN
2
. The fill should stop after a confirming (CHECK) SPLASH GUARD
period.
t Simulate an over fill by lowering the next thermistor into the LN
2
. HIGH
LEVEL alarm should sound with 10 seconds.
t Re-install sensor assembly and thermocouple into sensor tube as before.
Open supply valve on LN
2
supply.
31
KRYOS
Indicates High Liquid Level
1. Determine actual liquid level using a dipstick. 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.
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.
t Mark the sensor assembly at top of tube to assure re-assembly.
t Close liquid supply valve at source.
t Remove sensor assembly from sensor tube. DO NOT FORCE. Fill solenoid
valve should open and LOW LEVEL alarm should be activated.
t Select MENU, LEVEL SENSING, TEST LEVEL SENSORS. An “L” or “G” will
indicate individual thermistor status (L = Liquid and G = Gas).
t 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.
t Return to the main menu and submerge the START FILL THERMISTOR IN
LIQUID. Note that the low level alarm ceases, fill solenoid valve is still open.
Control is flashing FILLING.
t Manually press STOP button and note that the fill solenoid valve closes.
t Press FILL button to re-open fill solenoid valve.
t Continue to lower the sensor until the STOP FILL thermistor is immersed in
the LN
2
. The fill should stop after a confirming (CHECK) SPLASH GUARD
period.
t Simulate an over fill by lowering the next thermistor into the LN
2
. HIGH
LEVEL alarm should sound with 10 seconds.
t Re-install sensor assembly and thermocouple into sensor tube as before.
Open supply valve on LN
2
supply.
31
KRYOS
Indicates High Liquid Level
1. Determine actual liquid level using a dipstick. 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.
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.
t Mark the sensor assembly at top of tube to assure re-assembly.
t Close liquid supply valve at source.
t Remove sensor assembly from sensor tube. DO NOT FORCE. Fill solenoid
valve should open and LOW LEVEL alarm should be activated.
t Select MENU, LEVEL SENSING, TEST LEVEL SENSORS. An “L” or “G” will
indicate individual thermistor status (L = Liquid and G = Gas).
t 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.
t Return to the main menu and submerge the START FILL THERMISTOR IN
LIQUID. Note that the low level alarm ceases, fill solenoid valve is still open.
Control is flashing FILLING.
t Manually press STOP button and note that the fill solenoid valve closes.
t Press FILL button to re-open fill solenoid valve.
t Continue to lower the sensor until the STOP FILL thermistor is immersed in
the LN
2
. The fill should stop after a confirming (CHECK) SPLASH GUARD
period.
t Simulate an over fill by lowering the next thermistor into the LN
2
. HIGH
LEVEL alarm should sound with 10 seconds.
t Re-install sensor assembly and thermocouple into sensor tube as before.
Open supply valve on LN
2
supply.