ULVAC CRYOGENICS INCORPORATED
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switch first, and wait for longer than 10 minutes after LN
2
production stops to
allow UW701N to cool down.
8.4 Corrective action in the event of an error
When errors occur in the equipments, please follow the procedure below and in
“12. Trouble Shooting”.
8.4.1 Corrective action when electric power failure occurs
MP-300K and GN-20i will be automatically restored in the event of a power-failure
and they will be rebooted automatically when the electricity comes back. However,
when the amount of LN
2
is 75% or more, LN
2
production may not be resumed at
the time of rebooting.
8.4.2 Corrective action when COMP. ALARM occurs
(1) Open the front right door and check the alarm light of UW701N.
STS 1-8 light up: The power supply error of UW701N has occurred. Check
whether the power supply is reverse-phased or
power-supply voltage is not low.
STS 2-8 light up: The internal temperature error of UW701N has occurred.
Please contact us.
STS 3-8 light up: The internal temperature error of UW701N has occurred.
Contact us.
STS 4-8 light up: The cooling water system error of UW701N has occurred.
Check the cooling water pressure and flow rate. Wait
about 30 minutes after adjusting to the normal range.
STS 5-8 light up: Helium gas pressure of UW701N is declining. Adjust the
Helium gas pressure to the normal range.
STS 6-8 light up: The cold head protection circuit is operating. The circuit
protector (CP2) of UW701N is turned on.
STS 7-8 light up: The protection circuit of the main part of a compressor is
operating. Check power-supply voltage and Helium gas
pressure. A power supply is re-switched on after
intercepting a power supply for several minutes after
adjusting to the normal range.
STS 8 light up:
The controller error of UW701N has occurred. Turn off the
power supply for several minutes, and turn on the power
again.
(2) Open the front right door, and press the RESET switch of UW701N with a thin
stick. If the UW701N is ready to be restarted, alarm light turns off and an
alarm buzzer also stops.
(3) Press RESET button on the MP-300K operation panel.
(4) When the fault is cleared, UW701N re-starts. When UW701N does not start
