121
Alarms and Alerts
There are a variety of different alerts and alarms in the system.
P — Pre-Alert: Part of the unit is temporarily down. The alarm
is not broadcast on the CCN network. The alarm relay is not
energized. After an allowable number of retries, if the function
does not recover, the pre-alert will be upgraded to an alert or an
alarm.
T — Alert: Part of the unit is down, but the unit is still partially
able to provide cooling or heating.
A — Alarm: The unit is down and is unable to provide cooling
or heating.
All alarms are displayed with a code of AXXX where the A is
the category of alarm (Pre-Alert, Alert, or Alarm) and XXX is
the number.
The response of the control system to various alerts and alarms
depends on the seriousness of the particular alert or alarm. In
the mildest case, an alert does not affect the operation of the
unit in any manner. An alert can also cause a “strike.” A “strik
-
ing” alert will cause the circuit to shut down for 15 minutes.
This feature reduces the likelihood of false alarms causing a
properly working system to be shut down incorrectly. If 3
strikes occur before the circuit has an opportunity to show that
it can function properly, the circuit will strike out, causing the
shutdown alarm for that particular circuit. Once activated, the
shutdown alarm can only be cleared via an alarm reset.
Circuits with strikes are given an opportunity to reset their strike
counter to zero. As discussed above, a strike typically causes the
circuit to shut down. Fifteen minutes later, that circuit will once
again be allowed to run. If the circuit is able to run for 1 minute, its
replacement circuit will be allowed to shut down (if not required
to run to satisfy requested stages). However, the “troubled” circuit
must run continuously for 5 minutes with no detectable problems
before the strike counter is reset to zero.
In addition, the compressors have several diagnostics monitor
-
ing the safety of the system, which may cause a number of at
-
tempts to be re-tried before locking out the system from opera
-
tion. This feature reduces the likelihood of false alarms causing
a properly working system to be shutdown incorrectly.
For the compressor and circuit diagnostics, some of these
alerts/alarms will not broadcast an initial failure to the CCN
network until all attempts to recover have occurred and failed.
These alerts will be accessible in the alarm history of the con
-
trol (
Alarms
HIST
).
All the alarms and alerts are summarized in Table 92.
Table 92 —
Alert and Alarm Codes
ALARM OR
ALERT
NUMBER
DESCRIPTION
ACTION TAKEN BY CONTROL
RESET METHOD
T048
CktA, Oil Return Not Reliable With Only One Comp Available
Circuit shut down
Automatic
T049
CktB, Oil Return Not Reliable With Only One Comp Available
Circuit shut down
Automatic
T051
Circuit A, Compressor 1 Failure
Compressor locked off (after 3 strikes)
Automatic then manual after 3 strikes
A051
Circuit A, Compressor 1 Stuck On Failure
Compressor locked off
Manual
T052
Circuit A, Compressor 2 Failure
Compressor locked off (after 3 strikes)
Automatic then manual after 3 strikes
A052
Circuit A, Compressor 2 Stuck On Failure
Compressor locked off
Manual
T053
Circuit A, Compressor 3 Failure
Compressor locked off (after 3 strikes)
Automatic then manual after 3 strikes
A053
Circuit A, Compressor 3 Stuck On Failure
Compressor locked off
Manual
T054
Circuit B, Compressor 1 Failure
Compressor locked off (after 3 strikes)
Automatic then manual after 3 strikes
A054
Circuit B, Compressor 1 Stuck On Failure
Compressor locked off
Manual
T055
Circuit B, Compressor 2 Failure
Compressor locked off (after 3 strikes)
Automatic then manual after 3 strikes
A055
Circuit B, Compressor 2 Stuck On Failure
Compressor locked off
Manual
T056
Circuit B, Compressor 3 Failure
Compressor locked off (after 3 strikes)
Automatic then manual after 3 strikes
A056
Circuit B, Compressor 3 Stuck On Failure
Compressor locked off
Manual
T057
Circuit A, High Pressure Switch Trip Alert
Compressor locked off (after 3 strikes)
Automatic then manual after 3 strikes
A057
Circuit A, High Pressure Switch Trip Alarm
Compressor locked off
Manual
T058
Circuit B, High Pressure Switch Trip Alert
Compressor locked off (after 3 strikes)
Automatic then manual after 3 strikes
A058
Circuit B, High Pressure Switch Trip Alarm
Compressor locked off
Manual
T059
Circuit A, Compressor 4 Failure
Compressor locked off (after 3 strikes)
Automatic then manual after 3 strikes
A059
Circuit A, Compressor 4 Stuck On Failure
Compressor locked off
Manual
T060
Circuit B, Compressor 4 Failure
Compressor locked off (after 3 strikes)
Automatic then manual after 3 strikes
A060
Circuit B, Compressor 4 Stuck On Failure
Compressor locked off
Manual
T062
Circuit A Suction Pressure Alert
Alert Only
Automatic
T063
Circuit B Suction Pressure Alert
Alert Only
Automatic
T064
EXV A1 Superheat Outside Range
Alert Only
Automatic
T065
EXV A2 Superheat Outside Range
Alert Only
Automatic
T066
EXV B1 Superheat Outside Range
Alert Only
Automatic
T067
EXV B2 Superheat Outside Range
Alert Only
Automatic
A068
Circuit A Suction Gas Thermistor Failure
MLV Disabled
Automatic
T072
Evap. Discharge Reset Sensor Failure
No supply air reset applied
Automatic
T073
Outside Air Temperature Thermistor Failure
No OAT functions allowed
Automatic
T074
Space Temperature Thermistor Failure
No SPT functions allowed
Automatic
T075
Return Air Thermistor Failure
No RAT functions allowed
Automatic
T076
Outside Air Relative Humidity Sensor Fail
No outside air RH functions allowed
Automatic
T077
Space Relative Humidity Sensor Failure
No space RH functions allowed
Automatic
T078
Return Air Relative Humidity Sensor Fail
No return air RH functions allowed
Automatic
T079
Mixed Air Relative Humidity Sensor Fail
No mixed air RH functions allowed
Automatic
T082
Space Temperature Offset Sensor Failure
No space temperature offset applied
Automatic
T090
Circ A Discharge Press Transducer Failure
Circuit shut down
Automatic
T091
Circ B Discharge Press Transducer Failure
Circuit shut down
Automatic
T092
Circ A Suction Press Transducer Failure
Circuit shut down
Automatic
Summary of Contents for WeatherExpert 48N2
Page 135: ...135 Fig 18 48 50N Typical Power Schematic Nominal 075 Ton Unit Shown ...
Page 136: ...136 Fig 19 48 50N Typical Power Schematic Nominal Ton 90 150 Units Shown ...
Page 137: ...137 Fig 20 48 50N Main Base Board Input Output Connections ...
Page 138: ...138 Fig 21 48 50N RXB EXB CEM Input Output Connections a48 9307 ...
Page 139: ...139 Fig 22 48 50N EXV SCB Input Output Connections a48 9308 ...
Page 140: ...140 Fig 23 48N Typical Modulating Gas Heat Unit Control Wiring ...
Page 141: ...141 Fig 24 50N Typical Electric Heat Unit Control Wiring ...
Page 144: ...144 Fig 27 48N Typical Gas Heat Section Wiring Nominal Ton 120 to 150 Units ...
Page 145: ...145 Fig 28 48 50N Typical Power Component Control Wiring 460 v ...
Page 146: ...146 Fig 29 48 50N Component Control Wiring 575 v Nominal Ton 075 to 150 Units ...
Page 147: ...147 Fig 30 48 50N Component Arrangement Power Box ...
Page 148: ...148 Fig 31 48 50N Component Arrangement Control Box ...
Page 240: ...240 APPENDIX D VFD INFORMATION CONT Fig G VFD Bypass Wiring Diagram WHEN USED ...