The Burner Control Uses; Burner Control Safety Parameters (Established By The Oem) - CleaverBrooks CFC Operation, Service & Parts Manual

CB FALCON

The Burner Control Uses:

Inputs
All digital inputs are conditioned to eliminate response to
spurious noise and transient events while preserving the
required response.
FLAME
The flame signal includes signal conditioning, flame-on timing,
and flame-off (FFRT) timing. The control responds to loss of
flame and the abnormal presence of flame as defined by the
equipment setup.
LOAD (OR LIMIT) CONTROL INPUT (LCI) (J6 TERMINAL 3)
The LCI typically includes all of the limits that cause a burner to
hold or recycle. For burner control sequences that use it, a
burner will not fire if the LCI input is off. If the LCI turns off
during a burner run cycle, the system will return to standby.
INTERLOCK (ILK) (J5 TERMINAL 1)
The ILK input typically includes all of the limits that cause a
burner to lock out if it turns off during a run cycle, must turn on
within some seconds after demand is present during purge. An
example is an airflow switch. The equipment setup will define
the response to this signal.
INTERRUPTED AIR SWITCH (IAS) (J6 TERMINAL 2)
The IAS input can be used to connect an airflow switch that
normally opens during the Run state at low modulation rates,
and thus cannot be in the interlock circuit. The equipment
setup will define the response to this signal.
PRE-IGNITION INTERLOCK (PII) (J6 TERMINAL 5)
The Pre-ignition interlock typically includes a proof of closure
switch from the main valve. If it is on, then the valve is closed.
The equipment setup will define the response to this signal.
HIGH FIRE PROVING SWITCH (HFS) (J7 TERMINAL 2)
(DEVICE SPECIFIC)
A control may use an HFS, such as during Prepurge to prove
that a damper is in the proper position or that airflow is
sufficient. The equipment setup will define the response to the
HFS signal.
LOW FIRE PROVING SWITCH (LFS) (J7 TERMINAL 1)
(DEVICE SPECIFIC)
A control may use an LFS, such as during ignition to prove that
a damper is in the proper position. The equipment setup will
define the response to the LFS signal.
STAT (J8 TERMINAL 3), REMOTE STAT, AND LCI AS
DEMAND INPUTS (J6 TERMINAL 3)
The presence of demand may be configured to be:
• the on condition of the Stat input
• a message from a Remote Stat
• the on condition of the LCI input
• or may be driven by the sensor status alone
The presence of demand causes pump turn-on as a primary
effect, and will cause the burner control to fire only if a setpoint
demand signal is also received from the subsystem, which is
750-265
monitoring temperature. If burner demand exists, then the
burner control will attempt to light the burner and if this
succeeds, release control to the modulation source. However if
a hold condition exists, then the burner control will remain in
the hold condition until that condition reverts to normal. The
equipment setup will define the response to demand signals.
Outputs
MODULATION OVERRIDE
The burner control will control the modulation output when the
burner is off and during burner startup and shutdown by driving
the modulation rate directly, overriding the normal source for
modulation control, according to this table:
During
Standby
Prepurge
Ignition (PFEP, MFEP,
DSI)
Run stabilization
Postpurge
Lockout
BLOWER MOTOR (J5 TERMINAL 6,7)
The blower output will be operated to control a blower motor:
the terminal will be energized at the start of prepurge and
remain on through the end of postpurge, to establish airflow for
those systems that require this function.
However, when the Hot Surface Ignitor function is enabled, the
terminal will be operated as an Ignition Output.
EXTERNAL IGNITION TRANSFORMER (J5 TERMINAL 4)
PILOT VALVE (J5 TERMINAL 2) /MAIN VALVE (J5
TERMINAL 3) AND INTERNAL SAFETY RELAY (EXT. IGN/
PV / MV/ SR)
The burner control operates these relays and monitors their
feedback to ensure that they are in the correct state. These
relays provide the electrical power to energize the External
Ignition Transformer, Pilot Valve and Main Valve terminals. If
an output is not in its proper state, the system will respond with
a lockout or recycle.
FLAME VOLTAGE (TEST JACKS)
This voltage will represent the flame strength using a 0 to 15V
range, where 0.8 volts indicates the presence of flame.
Burner Control Safety Parameters
(Established by the OEM)
The following parameters may be modified only by using the
process for safety data described in "Commissioning" on
page 18.
The parameters occur here in their order of use in a typical
burner sequence.
56
The firing rate will be set to
Lightoff rate
Prepurge rate
Lightoff rate
Lightoff rate
Postpurge rate
Lightoff rate