Operational Features; Lockout History - CleaverBrooks CFC-500 Operation, Service And Parts Manual

OPERATIONAL FEATURES

Self Test
The Safety Processor performs Dynamic Self Checks that
supervise microcomputer performance to ensure proper
operation. The microcomputer tests itself and its associated
hardware with comprehensive safety routines. Any malfunction
will be detected by the microcomputer to cause a safety
shutdown and cause the Dynamic Safety Relay to de-energize
all safety-critical loads.
Initialization
The CB Falcon will start up in either the configured or
unconfigured condition. In the Configured condition it is ready
to operate a burner.
The Falcon is in the unconfigured condition whenever a safety
parameter requires editing (Commissioning). The Falcon
remains unconfigured and will not operate a burner until all
safety parameters have been reviewed and confirmed.
Safety Lockout
The Falcon can be set up to maintain a lockout condition on
power interruption or to reset the lockout on a power
interruption.
Reset
Pressing and releasing the reset button (or the remote reset
input) causes a lockout condition to be cleared, and the
microcomputer that operates the burner control part of the
Falcon to reinitialize and restart.
A safety lockout can also be reset through a writable
parameter from the system display through Modbus.
Fault Handling
The Falcon implements two kinds of faults: lockouts and alerts.
Lockout messages are stored in the Falcon non-volatile
memory (File and lockout remain with power interruption) and
Alerts are stored in the volatile memory (file clears on power
interruption).
• Lockout causes the burner control to shutdown and
requires manual or remote reset to clear the lockout.
• It always causes the alarm contact to close.
• Gets logged into the 15 item lockout history.
• Alerts include every other kind of problem that does not
shut the burner down. Examples of alerts are faults from
non–safety functions or abnormal events that are relevant
to an operator or end user.
• Alerts never require manual intervention to reset
them (an alert is not a condition, it is an event).
• Whether the alarm contact closes or not is
programmable by the OEM for each alert.
• Alerts are logged in the 15 item alert history and
sorted in chronological order. Only one instance of
each alert fault code occurs in the history,
corresponding to the most recent occurrence of the
alert.
Sensor Select
Inputs for Header or Outdoor temperature sensors might be
available from various sources, so parameters are provided to
select the input source. These parameters determine:
• how temperatures are obtained;
• if/where temperature information is stored;
• where a control loop gets its data.
Sensor Signal Conditioning
The analog sensors signal includes filtering to reduce the effect
of noise and spurious read events. This filter includes
averaging to smooth sensor output and reject occasional
spurious values to prevent them from affecting the average.
Sensors won't cause a fault condition unless the value is
requested for control purposes. Thus it is not a fault for a
sensor to be absent or otherwise non-operational unless it is
used for something (i.e. outdoor temperature).
If its value is requested and a sensor fault exists, then an alert
condition is triggered by the requestor in response to the fault
status, unless this is either a normal operating condition (e.g.,
the DHW sensor used as a switch) or causes a lockout (e.g., a
failed high limit sensor).
Safety sensors include the comparison of redundant sensors.
If a safety sensor mismatch occurs this is reported to the caller
as a fault (which will cause the operator to take an appropriate
action).
Sensor faults will include:
• out-of-range: low
• out-of-range: high—distinguishing low vs. high is
important when sensor inputs are being used as digital on/
off inputs; in this case these out-of-range values are not
faults.
• mismatch—applies to safety sensors, where two sensors
are compared.
Non-Volatile Memory
The Falcon will store the following items in non-volatile
memory (Information remains in control on power interruption):
• Factory configuration data
• Parameter Control Blocks (for example, Read only and
Password Settings)
• All configuration parameters
• The 15 item lockout history
• Cycle and Time history

Lockout History

The lockout history contains 15 records. Each record is a
snapshot of the following values as they existed at the time of
the lockout.
• Burner Lockout/Hold identifies the cause of the lockout.
• Burner State identifies the state of the burner control (e.g.
standby, purge, run).
• Burner Displayed Time: mm:ss is the displayed timer
used by the Burner Control at the time of lockout (e.g.
prepurge time, ignition time, etc.).
• Annunciator First-out is the first-out code for the lockout.
• Burner Run Time is the elapsed time of burner operation.
• Burner Cycle Count is the number of burner cycles (based
on the main valve being turned on).
• All analog sensor values (Inlet, Header, Outlet, Outdoor,
DHW, Stack, or Steam)
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CB FALCON
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