Fault Recovery And Reset - Daikin Microtech III Operation And Maintenance Manual

Fault recovery and reset

■ High pressure/low pressure reset
• After the HP circuit is closed, the unit does not return
to normal operation until the alarm is manually
reset. The unit is locked out in this manner until the
unit can be serviced. The alarm is reset by a short
interruption of unit power, by holding down the
tenant override button for more than 10 seconds,
or via the Building Automation System (BAS).
■ Remote reset of automatic lockouts
• The remote reset feature provides the means
to remotely reset some lockouts generated by
high-pressure and/or low-temperature faults.
When the MicroTech III unit controller is locked
out due to one of these faults, and the cause
of the fault condition has been cleared, apply a
ground signal to the tenant override input (screw
terminal connection at TB1 pin 4) for more than
10 seconds will force the controller to clear the
lockout. Cycling unit power also clears a lockout
if the conditions causing the fault have been
alleviated.
Table 8: Fault recovery and reset
Fault Description
IO Expansion Communication Fail
Invalid Jumper Configuration
Low Voltage Brownout
All Sensor Failures
Compressor High Pressure
Compressor Low Pressure
Compressor Low Suction Temp or Freeze Fault Detect (Heat & Cool)
Compressor Low Suction Temp or Freeze Fault Detect (Dehumidification)
Condensate Overflow
Low Entering Water Temp.
EEPROM Corrupted
Waterside Economizer Low Temp. Cutout
Indicates auto recover is subject to intelligent alarm reset. Alarm auto recovers on first two occurrences, locked out on third within 24 hour period.
Note: 1
OM 1239
M
■ Intelligent alarm reset
• The intelligent reset feature helps to minimize
nuisance trips of automatic lockouts caused by
low-temperature faults. This feature clears faults the
first two times they occur within a 24-hour period
and triggers an automatic lockout on the 3rd fault.
The fault remains active until the alarm is manually
cleared. At the end of the 24 hour period, all counts
for that specific intelligent reset alarm are cleared to
zero only if the occurrence counter is presently less
than the value of three. The 24-hour period and alarm
counts are stored in memory that is cleared when
power is cycled.
Note: Cycling unit power will always reset any type of
fault. Faults will clear as defined in
Auto Recovery Tenant Override Button Reset
Yes
No
Yes
No
No
No
Yes 1
Yes
Yes
Yes
No
Yes
17
t III u C
ICro eCh nIt ontroller
Table 8.
Network Reset
No No
No No
No Yes
No Yes
Yes Yes
Yes Yes
Yes Yes
Yes Yes
No Yes
No No
No No
No No
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