Compressor Failure Alerts - Carrier AquaSnap 30MPA Series Controls, Start-Up, Operation, Service, And Troubleshooting

ALARM/ ALARM
ALERT OR DESCRIPTION
CODE ALERT
A221 Alarm Condenser Pump
Interlock Opened During
Normal Operation
A222 Alarm Condenser Pump
Interlock Closed When
Pump is Off
Strainer Blowdown
T302 Alert Scheduled
Maintenance Due
Current Sensor Board
T500 Alert
A1 Failure
Current Sensor Board
T501 Alert
A2 Failure
Current Sensor Board
T502 Alert
A3 Failure
T950 Alert Loss of Communication
with Water System
Manager
A951 Alarm Loss of Communication
with Chillervisor System
Manager
LEGEND
CCN — Carrier Comfort Network
CSB — Current Sensor Board
CSM — Chiller System Manager
EEPROM — Electronic Eraseable Programmable Read Only Memory
EMM — Energy Management Module
EWT — Entering Fluid Temperature
EXV — Electronic Expansion Valve
LCW — Leaving Chilled Water
LWT — Leaving Fluid Temperature
MBB — Main Base Board
RGT — Return Gas Temperature
SCT — Saturated Condenser Temperature
TXV — Thermostatic Expansion Valve
WSM — Water System Manager

COMPRESSOR FAILURE ALERTS

A048 (Circuit A Compressor Availability Alarm) — This
alarm occurs when two compressors are unavailable to run on
a 3-compressor circuit. The control ensures proper oil return by
ensuring a circuit does not operate with one compressor for
longer than one hour of cumulative run time.
T051, T052, T053 (Circuit A Compressor Failures) — Alert
codes 051, 052, and 053 are for compressors A1, A2, and A3
respectively. These alerts occur when the current sensor (CS)
does not detect compressor current during compressor opera-
tion. When this occurs, the control turns off the compressor.
If the current sensor board reads OFF while the compressor
relay has been commanded ON, an alert is generated.
POSSIBLE CAUSES
Compressor Overload — Either the compressor internal over-
load protector is open or the external overload protector (Kri-
wan, Copeland CoreSense, or Lodam module) has activated.
The external overload protector modules are mounted in the
compressor wiring junction box. Temperature sensors embed-
ded in the compressor motor windings are the inputs to the
module. The module is powered with 24 vac from the units
main control box. The module output is a normally closed con-
tact that is wired in series with the compressor contactor coil.
Table 54 — Alarm and Alert Codes (cont)
WHY WAS THIS
ALARM
GENERATED?
If configured for con-
denser pump interlock
and the flow switch
opens for 15 seconds
during normal
operation (or when
the condenser pump
relay is on when con-
denser pump control
is configured.)
If configured for con-
denser pump interlock
condenser pump con-
trol, and the flow
switch is closed
when pump relay is off.
Strainer Service
Countdown (S.T.DN)
expired. Complete strainer
blowdown and enter 'YES'
for Strainer Maintenance
Done (S.T.MN) item.
Alert occurs when CSB out-
put is a constant high value
Alert occurs when CSB out-
put is a constant high value
Alert occurs when CSB out-
put is a constant high value
No communications have
been received by the MBB
within 5 minutes of last
transmission
No communications have
been received by the MBB
within 5 minutes of last
transmission
63
ACTION TAKEN
BY CONTROL METHOD
Condenser and cooler
pumps shut off. Chiller
shut down
Chiller is not allowed to
start.
None Automatic
Compressor A1 shut
Automatic
down
Compressor A2 shut
Automatic
down
Compressor A3 shut
Automatic
down
WSM forces removed. Automatic
Chiller runs under own
control
CSM forces removed. Automatic
Chiller runs under own
control
In a compressor motor overload condition, contact opens,
de-energizing the compressor contactor.
Low Refrigerant Charge — If the compressor operates for an
extended period of time with low refrigerant charge, the com-
pressor ASTP device will open, which will cause the compres-
sor to trip on its overload protection device.
Circuit Breaker Trip — The compressors are protected from
short circuit by a breaker in the control box.
Wiring Error — A wiring error might not allow the compres-
sor to start.
To check out alerts T051-T053:
1. Turn on the compressor in question using Service Test
mode. If the compressor does not start, then most likely
the problem is one of the following: HPS open, open in-
ternal protection, circuit breaker trip, incorrect safety wir-
ing, incorrect compressor wiring or incorrect Copeland
CoreSense internal phase monitor wiring.
2. If the compressor does start, verify it is rotating in the cor-
rect direction.
RESET PROBABLE
CAUSE
Manual Failure of condenser
pump or controls.
Wiring error.
Manual Failure of condenser
pump relays or inter-
locks, welded
contacts.
Routine strainer
maintenance
required
CSB failure.
CSB failure.
CSB failure.
Failed module, wiring
error, failed
transformer, loose
connection plug,
wrong address
Failed module, wiring
error, failed
transformer, loose
connection plug,
wrong address