29
Complete Unit Stoppage
There are several conditions that can cause a complete unit
stoppage, including:
S A fault is active which causes the unit to shut down.
S Cooling and heating loads are satisfied.
S Programmed occupancy schedule.
S General power failure.
S Tripped 24-volt transformer circuit breakers.
S Blown fuse or circuit breakers
S Unit is turned off through the network.
Restart Procedure
Before attempting to restart the machine, check the faults and alerts
list to determine the cause of the shut down. If the shutdown fault
for a particular control function has occurred, determine and
correct the cause before allowing the unit to run under its own
control again. When there is problem, the unit should be diagnosed
in Service Test mode. The faults must be reset before the control
function can operate in either Normal mode or Service Test mode.
Faults and Alerts
Viewing and Clearing Unit Alarms
Presence of active alarms will be indicated on the SystemVu
display by the Alarm Status lights. When alerts are active the
yellow “ALERT” light will be lit. When faults are active the red
“FAULT” light will be lit. When the unit is operational, then green
“RUN” light will be lit. The SystemVu controller standby screen
will be updated with the active alarms for easy access. Presence of
active alarms may also be signaled on the Alarm Output terminals.
Each alarm may also be broadcast on the CCN network. Active
alarms and past alarm history can be reviewed and cleared via the
local display or a network device. The following menu locations
are used for the local display:
ACTIVE FAULTS -- Displays the list of active faults in order of
occurrence.
ACTIVE ALERTS -- Displays the list of active alerts in order of
occurrence.
HISTORY -- Displays the list of active and previously active faults
and alerts in order of occurrence with time and date.
RESET FAULTS/ALERTS --User command to manually reset
faults and alerts.
Each alarm can have up to 3 data points stamped along with date
and time to assist in troubleshooting. Pressing ENTER on the
alarm or expanded screen will provide these data points.
Diagnostic Alarm Codes and Possible Causes
Fault F010 – MBB LOW VOLTAGE
This fault occurs when the MBB supply voltages falls below 17
volts AC. When this occurs the control will shut down the unit.
This will automatically clear when the supply voltage rises above
19 volts AC. The cause of this fault is usually a brownout
condition, low supply voltage, or supply power missing a phase.
Fault F011 – MBB REFERENCE VOLTAGE
This fault occurs when the MBB internal microprocessor’ s DC
reference voltages is out of range. When this occurs the control will
shut down the unit. This will automatically clear when the DC
reference voltage goes back in range. The cause of this fault is
usually a MBB failure or supply voltage out of range.
Alert A012 – MBB ZERO CROSSING
This fault occurs when the MBB supply voltage frequency is out of
range. When this occurs the control will issue an alert. This will
automatically clear when the supply voltage goes back in range.
The cause of this fault is usually a MBB failure or supply voltage
frequencytohighortolow.
Fault F013 – MBB FUSE 2 OPEN
This fault occurs when the MBB’ s internal fuse number 2 exceeds
threshold temperature. When this occurs the control will shut down
the unit. This will automatically clear when the fuse temperature
gets back in range. The cause of this fault is usually a switch input
has a wiring error (short) or the switch pulled too much current.
Discrete input number 2, Fire Shutdown input, and the IGC fan
request are connected to fuse 2.
Fault F014 – MBB FUSE 3 OPEN
This fault occurs when the MBB’ s internal fuse number 3 exceeds
threshold temperature. When this occurs the control will shut down
the unit. This will automatically clear when the fuse temperature
gets back in range. The cause of this fault is usually a switch input
has a wiring error (short) or the switch pulled too much current.
Configurable discrete input numbers 12, 13, and 14 are connected
to fuse 3.
Alert A01 5 – MBB RNET VOLTAGE RANGE
This fault o ccurs when the MBB’s Rnet 12 volt output is out of
range. When this occurs the control will issue an alert, and any
accessory connected to the Rnet plug may not operate properly.
This will automatically clear when the voltage goes back in range.
The cause of this fault is usually a MBB failure or supply voltage
out of range.
Alert A01 6 – MBB 24VDC RANGE
This fault occurs when the MBB’s 24vdc output falls below 17
volts DC. When this occurs the control will put the Analog Input
number’ s 6, 7, and 8 into error state. This will automatically clear
when the voltage rises above 19 volts DC. The cause of this fault is
usually a MBB failure or supply voltage out of range.
Alert A01 7 – MBB 5VDC RANGE
This fault occurs when the MBB’s 5vdc output falls below 4.5
volts DC. When this occurs the control will put the Transducer
inputs into error state. This will automatically clear when the
voltage rises above 4.5 volts DC. The cause of this fault is usually
a MBB failure or supply voltage out of range.
Fault F018 – MBB EEPROM FAILURE
The unit will completely shut down. The serial EEPROM chip on
the MBB which stores the unit’s configuration is not responding.
Recovery is automatic but MBB board replacement may be
necessary. Cycling the power to the control should be tried before
board replacement.
Alert A01 9 – MBB CLOCK FAILURE
The alert occurs when the RTC clock chip on the MBB is not
responding. Time and date functions will not operate, such as local
occupancy schedules. The unit will default to 24/7 unoccupied
mode. Recovery is automatic but MBB board replacement may be
necessary. Cycling power to the control and reconfiguring the time
and date should be tried before board replacement.
Fault F020 – SOFTWARE ERROR
The unit will completely shut down. The software on the MBB is
not responding. Recovery is automatic if the software is able to
reset the board but software change may be necessary. Cycling the
power to the control should be tried before board replacement.
Alert A099 -- COMM LOSS WITH SIOB
This alert occurs when there has been a loss of communication
with the IO Board on the LEN bus. Any sensor inputs from the
board will be ignored and outputs will no longer be controlled.
Alert A10 0 – SAT SENSOR FAILURE
This alert occurs when the fan supply temperature sensor is in an
error state. Economizer cooling cannot occur while this alert is
active. The unit will not be able to honor SAT limits. This alert
resets automatically. The cause of the alert is usually a faulty
thermistor, a shorted or open thermistor caused by a wiring error,
or a loose connection.
Alert A101 – FST SENSOR RANGE
This alert occurs when the fan supply temperature sensor is outside
the range –40_F to 245_F (–40_Cto116_C). This alert resets
automatically . The cause of the alert is usually a faulty thermistor, a
To Next Page
Loading...
Need help?
General
