36
● Alarm codes and remedies
Alarm
Item Contents Causes Remedy
code
AL40 Flow rate range Flow exceeds the A forward or reverse Check for excessive flow. If a minus sign is
exceeded upper limit for flow exceeds the shown on the flow rate display when the
indication. Or, the specified range. alarm occurs, there might be a reverse flow.
flow exceeds the Correct the factor causing the reverse flow.
reverse flow rate When the actual flow enters the normal
range. range, the alarm lamp should turn off.
AL5 1 Registered data The registered Wrong flow path Set the correct flow path identifiers in
error 1 flow path identifiers identifiers setting. maintenance mode. If the MCF does not
are incorrect. Flow return to normal after the setting is changed,
rate cannot be reboot it. If the MCF does not return to
calculated correctly. normal after being restarted, call for repair.
AL52 Registered data The registered The registered If the MCF does not return to normal after
error 2 properties of the properties might be rebooting, call for repair.
flow sensor are corrupted.
incorrect. The flow Or, abnormal heater
rate cannot be voltage might be
calculated correctly. preventing proper
calculation.
AL8 1 Sensor error 1 The flow signal is The flow signal can If the cause of this alarm is excessive
outside the normal decrease greatly if reverse flow, the MCF will return to normal
range. foreign matter causes automatically when the flow falls within the
a short circuit or if measurable range.
there is an excessive If the alarm does not turn off in spite of a
reverse flow. normal reverse flow, ask for repair.
AL82 Sensor error 2 The flow signal The sensor might be If the MCF does not return to normal after a
may differ from the broken or the output few hours of dry air flow, call for repair.
actual flow. level might have
decreased. Foreign
AL83 Sensor error 3 matter or condensation
may be present on the
sensor.
AL84 Sensor error 4 Sensor heater The sensor may be If the MCF does not return to normal after a
voltage is outside broken or foreign few hours, call for repair.
the normal range. matter may be stuck to
it, causing a short circuit.
ALG 1 Device Checksum error Data might be If the MCF does not return to normal after
data error during EEPROM corrupted by electrical rebooting, call for repair.
ALG2 Property read/write process. noise.
Memory
error
ALG3
error
Setup data EEPROM write Try data setup again. If the MCF does not
error process might have return to normal after rebooting, call for
ended abnormally due repair.
ALG4 Integrated to power outage. After resetting the integrated flow, if the
data error MCF does not return to normal after
rebooting, call for repair.
Chapter 6. MAINTENANCE AND TROUBLESHOOTING