34
ULVAC CRYOGENICS INCORPORATED
Problem
Possible Cause
Corrective Action
AUTO READY switch is
turned OFF
(When LN
2
is not dispensed
automatically.)
Turn ON the AUTO READY
switch.
eco mode is ON.
(When LN
2
cannot be
dispensed manually.)
Cancel Eco mode and wait
for 6 minutes.
(8) Liquid Nitrogen does
not increase.
The equipment is in initial
start-up.
Wait for about half a day until
the dewar temperature is
lowered enough to store
liquid nitrogen.
The helium gas piping and
refrigerator cables are not
connected correctly.
Connect the helium gas lines
and refrigerator cables
properly.
The level sensor fails to
detect correctly.
Please contact us.
(9) The rate of Liquid
Nitrogen production
declines.
Cold head and oil adsorber
exceed the recommended
maintenance interval.
Conduct the maintenance
according to the time of
operation.
Helium charge pressure of
SA115-C is lowered.
Add helium to the specified
pressure. Please contact us
when this trouble occurs
frequently.
Amount of evaporation from
dewar increased.
Please contact us.
EMP absorbs special gas
such as helium.
Please contact us.
Ice or frost adheres to inside
the dewar or around the cold
head.
Please contact us.
The purity of Nitrogen gas is
not sufficient.
Check the purity of nitrogen
gas supplied.
