Beckett CG4 - Manual (Page 18)

18
Section: SEQUENCE OF OPERATION
Sequence of Operation
Delayed Ignition,
Explosion, and Fire
Hazards
Use only the Beckett 7590 Control on
the CG4 Burner.
This operation sequence is
typical for operation with a 7590
control. This is the only control approved for use on
the CG4 Gas Power Burner.
Do not start the burner yet.
(Reference
Table 6 )
○ Call for heat, Status LED is turned on.
─ Control performs safe-start check
─ If safe-start fails, control locks out.
─ If safe-start passes, control checks for presence
of flame.
─ If flame is present, control will enter hold state
until flame is no longer present. Flame LED
and Status LED will flash until flame is no longer
present.
─ If flame is not present, control will check status of
air proving switch. If switch is closed, (indicating
the pressure switch is stuck) control will enter
lockout.
Table 6 – Operating Sequence
LEDs
Call for Heat
FLAME
MV STATUS
Status LED
turns on
Motor Start
FLAME
MV STATUS
Status LED
ON
Pre-purge
FLAME
MV STATUS
Status LED
Flashes
Ignition
FLAME
MV STATUS
Status, MV
LEDs On
Run
FLAME
MV STATUS
Status, MV,
Flame LEDs On
End Call for Heat
FLAME
MV STATUS
LEDs Off
Timers &
Timings
Pre-purge Timer
1 - 240 Seconds
Ignition Trial
Timer
4 - 15 Seconds
Flame Check On On On On On
Motor/Blower Blower Starts On On On Off
Air Switch Check On Air Switch Closes On On On
Igniter On Off Off
Gas Valve On On Off
○ If the air proving switch is open, the motor will start.
Once the air proving switch closes, pre-purge will begin
(lasting 30 seconds). Pre-purge or ignition timings will
not start until the air proving switch closes.
─ The air proving switch must close to prove
combustion air is present. If switch fails to close
during the specified period, the control will enter
lockout.
○ When pre-purge is completed, the control turns on the
igniter and the gas valve. MV LED will turn on.
─ Spark continues until end of ignition timing or
until flame is proved.
○ Once flame is proved, The Flame LED is turned on
and the spark is turned off. The gas valve and MV LED
remain energized.
─ If flame is not proved, the control will lockout or
enter the inter-trial waiting period. Status LED
will flash rapidly for lockout or slowly for inter-trial
waiting.
─ If multiple trial logic is used, the control will
complete the trials for ignition
─ When flame is proved the control will continue in
run mode until the end of the call for heat.
○ When the call for heat is ended, the gas valve, MV
LED, Flame LED, Status LED and motor turn off.
Additional information on control operation is available in
the GeniSys 7590 Control Manual (61981-001).