1-6
Chapter 1. OVERVIEW
Description of 7-segment display
z Sequence code display
Normally, a code is displayed corresponding to the present stage of the operation
sequence. The table below shows the displayed code and the concurrent stage in the
sequence.
Display Sequence Description
– – Standby Standby when the start contact input is off.
P1 Start check Start check of this device and of the AUD300C.
P2 Ignition trial Ignition of the pilot burner.
P3 Pilot Stabilization Check to confirm reliable pilot burner ignition.
P4 Main Trial Ignition of main burner.
P5 RUN Flame monitoring after main burner ignition.
PL Lockout Lockout
z Alarm code display
When lockout occurs, the display automatically changes to alarm code display, and
the lockout sequence code and alarm code are alternately displayed.
Display Alarm name Description
E0 Start check alarm The start check was not completed for some reason such
as momentary power failure or part malfunction.
E1 Interlock alarm Interlock occurred.
E2 False flame A false flame such as a remaining flame was detected.
E3 UV alarm A flame was detected even though the shutter output
was off.
E4 Ignition failure No flame was detected at the completion of the ignition
trial.
E5 Flame failure A flame failure occurred in the following sequence:
•
Pilot Stabilization
•
Main Trial
•
RUN
EE Other When the cause of lockout cannot be identified:
•
In cases where power was turned off before CPU error
determination
•
In cases where vibration during transportation, etc.,
cause latch relay to switch to lockout
Handling Precautions
•
If the DISP switch is pressed while an alarm code is displayed, the flame volt-
age is displayed rather than the alarm code. When DISP is pressed again, the
sequence code and the alarm code are alternately displayed.
•
If the system is locked out and then reset, the display prior to lockout resumes.
For example, if lockout occurs while flame voltage is displayed, the display
changes to alarm display, in which the alarm code and sequence code are al-
ternately displayed. After reset, flame voltage display resumes.