American Standard 4A6V0024A1000B Service Facts page 24

V V a a r r i i a a b b l l e e S S p p e e e e d d A A l l e e r r t t C C o o d d e e s s
Display
Alert
Alert
Assembly
Group
Code
Text
LIMP MODE
Limp
175 Along
Mode
LIMP MOD LO
Modbus
Communi-
176 DRV COMM LO
cation
Failure
CUR DER
CUR EX DER
SW CUR CO
Drive
177 Current
Failure
HW CUR CO
CURRENT LO
24
Sub-
A/TZONE
State action on
alar-
850/950
occurrence
m
High or Low superheat
detected for at least
20 minutes. Limp
Mode can also be
triggered by Loss of
Sensor reading. Look
0 Err 175.00
for Sensor Error. Limit
Compressor Speed to
a constant value.
Loss of Suction
Pressure Transducer
reading forces shut
down and Hard Lock
1 Err 175.01
With communication
0 Err 176.00 error message, the
drive must shut down.
Compressor speed
N/A
0
Derated.
Compressor speed
Derated. This alert
shall be an indication
1 Err 177.01
of an extended
Derated performance.
Emergency shutdown.
Control will clear the
2 "Wait"
fault and retry every 5
minutes.
Emergency shutdown.
Control will clear the
3 "Wait"
fault and retry every 5
minutes.
Emergency shutdown
4 Err 177.04
Alert
State action on
Description
clearance
High or Low
superheat
detected for at
least 20 minutes.
Limp Mode can
Ramp up to
also be triggered
demand speed
by Loss of Sensor
(normal operation)
reading. Look for
Sensor Error.
Limit Compressor
Speed to a
constant value.
Shutdown. Can't
Can be cleared only
start system
on power cycle.
without Service
After power cycle,
being called.
the compressor
Send error to
shall resume
thermostat and
normal operation.
alert menu in CDA
Can be cleared only
on power cycle.
Loss of internal
After power cycle,
communication
the compressor
within the Drive.
shall resume
normal operation.
Internal Derate is
Ramp up to
active due to high
demand speed
Drive output
(normal operation).
current
Drive current is
above threshold
Ramp up to
and the system is
demand speed
being Derated for
(normal operation).
an extended
period of time.
Drive output
Resume normal
current exceeds
operation
internal limit set
for current sensor
Drive output
Resume normal
current exceeds
operation
internal limit set
for current sensor
5 occurrences of
HW CUR CO in 1
Can be cleared only hour, or 15
on power cycle. occurrences of
After power cycle, SW CUR CO in 1
the compressor hour. Each hour of
shall resume runtime without a
normal operation. HW or SW cutout
will reduce the
total count by 1.
Possible Cause
Problemwith
refrigerant pressure
or flow (high or
lowsuperheat).
Sensor Faulted (out of
range). Dome temp,
suction temp,
ambient temp, indoor
EEV temp sensor
(EEV in safe mode).
Failed suction
pressure transducer,
or multiple
simultaneous sensor
failures. Evaluate
sensor failure alerts
for troubleshooting /
resolution.
Loss of internal
communication
within the Drive. On a
persistent 176.00
error, the technician
should cycle power to
the ODU. If error
176.00 returns,
replace the Drive. If
replacement Drive
has the same issue,
investigate for EMI
and source.
High load conditions.
High load conditions.
High load condition.
Overcharge, dirty coil
(s), low airflow,
recirculation,
compressor failure,
Drive hardware
failure (Run Drive
Diagnostics).
Compressor failure
(locked rotor, shorted
windings), Drive
hardware failure (Run
Drive Diagnostics)
High load conditions
for 5 consecutive over
current cutout
periods. GoTo Drive
Diagnostic Test in
CDA. Also see
Compressor
Verification
Flowchart. Choke
possibly not plugged
in.
4A-V0-SF-1G-EN