Problems - Daikin MicroTech III Operation Manuals

Problems

Hi DL Temp: Problem
Normal compressor control is limited when a high discharge
line temperature conditions occur . If the variable speed
compressor is operating and the discharge line temperature
is greater than 250F for 15 seconds a High Discharge Line
Temperature Event is generated and the variable speed
compressor capacity is reduced every 15 seconds until the
discharge line temperature falls below 220F . If the discharge
line temperature is above 250F continuously for 3 minutes the
variable speed compressor is stopped and a High Discharge
Line Temperature problem alarm is generated . The alarm must
be manually cleared .
DRT2 Sensor: Problem
This alarm occurs when the DRT2 sensor input is shorted or
open circuited for the Sensor Alarm Delay (default 30 seconds) .
It can also occur when the variable speed compressor is off
and the input is above 329°F or the compressor has been off
for 20 minutes and the input is below -4°F .
When this alarm is active compressor cooling operation is
disabled .
The alarm must be manually cleared once corrective action is
taken .
Variable Compressor: Problem
If the variable speed compressor is enabled (MCB-D03
is closed) and commanded to run for 30 seconds but the
controller fails to receive the variable speed run verification
input (EMC-X4 is open) the variable speed compressor enable
output (MCB-D03) is cycled OFF for 5 seconds ( a variable
speed Compressor Emergency Stop Control Event is logged)
and then back on . The variable speed compressor is then
ramped to 45% . If this occurs 3 times in a 30 minute period the
variable speed compressor is shut off and a variable speed
Compressor Problem alarm is generated .
Low Discharge Pressure: Problem
Normal variable speed compressor control is limited when
a low pressure condition occurs on the variable speed
compressor circuit . If the variable speed compressor is
operating and the suction pressure (PTS) is less than 250 PSI
a Low Pressure Unloading Control Event is generated and
the variable speed compressor speed is increased every 30
seconds until either the suction pressure rises above 250 PSI
or remains lower than 250 PSI continuously for 15 minutes .
If the suction pressure is below 250 PSI continuously for 15
minutes the variable speed compressor is shut OFF and a
Low Pressure Problem alarm is generated . The alarm must be
manually cleared .
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Low Discharge Superheat: Problem
Normal compressor control is limited when low superheat
conditions occur . If the variable speed compressor is operating
and the discharge superheat is less than 20F continuously
for 15 minutes a Low Discharge Superheat Unloading Control
Event is generated and the variable speed compressor
speed is increased . The variable speed compressor speed
is increased every 10 minutes as long as the discharge
superheat remains less than 20F until the maximum allowed
variable speed compressor speed (based on unit size) is
reached . If the discharge superheat remains below 20F the
variable speed compressor is shut off and a Low Superheat
alarm is generated .
High Discharge Superheat: Problem
Normal compressor control is limited when high superheat
conditions occur . If the variable speed compressor is operating
and the discharge superheat is greater than 75F continuously
for 15 minutes a High Discharge Superheat Unloading Control
Event is generated and the variable speed compressor
speed is decreased . The variable speed compressor speed
is decreased every 10 minutes as long as the discharge
superheat remains great than 75F until the minimum allowed
variable speed compressor speed (based on unit size) is
reached . If the discharge superheat remains above 75F the
variable speed compressor is shut off and a High Superheat
alarm is generated .
PTD2 Sensor: Problem
This alarm occurs when either the circuit 2 discharge line
pressure inputs (PTD2) remains above 700 psi for 10 seconds
or a compressor on circuit 2 has been operating for 60 seconds
and the PTD2 value remains less than 155 psi . When this
alarm is active compressor cooling operation is disabled .
The alarm must be manually cleared once corrective action is
taken .
PTD1 Sensor: Problem
This alarm occurs when either the circuit 1 discharge line
pressure inputs (PTD1) remains above 700 psi for 10 seconds
or a compressor on circuit 2 has been operating for 60 seconds
and the PTD1 value remains less than 155 psi . When this
alarm is active compressor cooling operation is disabled .
The alarm must be manually cleared once corrective action is
taken .
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