31
INSTALLATION
IMAX XTRA EL
-
Installation & Servicing
31 OPERATING SEQUENCE
Standby
yes
yes
yes
yes
yes
yes
yes
yes
no
yes
no
no
no
no
no
no
no
no
no
yes
yes
Heat demand on?
Temp. < setpoint?
APS open
fan stand-off?
APS
closed?
Demand
off or Temp. >setpoint?
Heat Demand Off?
Pump off
Flame detected?
Demand On
& Temp. <Set point & Anti-cycle
done?
Fan On
10s Fan Pre-purge
Pump On
Fan on
Spark Generator On
Gas Valve On
5s Ignition Period
Burner Output controlled relative to
Heat Demand by varying Fan Speed
Burner On
Spark Generator Off
1st Stabilisation Period
Gas Valve Off
Post Purge
Fan Off
Pump Overrun
Note1. The fan runs for
4 mins after the burner
switches off
Note2. Ignition cycle
occurs 5 times before
lockout
Standby
25 secs?
25 secs?
Error
Error
INST
ALLA
TION