Product data

7800 SERIES S7800A1142 KEYBOARD DISPLAY MODULE
65-0288-1 12
a
See Table 8 for optional messages.
TROUBLESHOOTING
After the KDM is installed, return the 7800 SERIES to normal
operation, restore power and run the system through at least
one complete automatic cycle. For complete Troubleshooting
and System Checkout information, see form 65-0229.
7800 SERIES System Diagnostics
Troubleshooting control system equipment failures is made
easier with the 7800 SERIES self-diagnostics and first-out
annunciation. The S7800 provides visual annunciation by
displaying a fault code and fault or hold message on the
display.
Self-diagnostics of the 7800 SERIES enables it to detect and
annunciate both external and internal system problems.
Internal faults and external faults such as interlock failures,
flame failures and false flame signals are annunciated by the
KDM via the 7800 SERIES Relay Module.
The KDM displays a sequence status message indicating
STANDBY, PREPURGE, PRE-IGNITION, SAFETY 1, PILOT
IGN, PILOT STAB., MAIN IGN, RUN or POSTPURGE, as
appropriate. The selectable messages also provide visual
indication of current status and historical status of the
equipment, such as: Flame Signal, Total Cycles, Total Hours,
Fault History, Diagnostic Information and Expanded
Annunciator terminal status (if used). With this information,
most problems can be diagnosed without extensive
trial-and-error testing.
Table 21 provides the sequence and status hold messages.
Table 4. Expanded Annunciator.
Selectable Message
a
(Second Line) Display Value (Second Line) First Line Message
Expanded Annunciator↔
Expanded Annunciator (EA not
connected)<
ÈEA
Current Status (CS:)
a
EA Message< ÈEA
Valve Closure (Valve Close) T5 = 1 or 0< ÈEA
Burner Switch (Burner Sw.) T5 = 1 or 0< ÈEA
Operating Control (OperControl) T6 = 1 or 0< ÈEA
Auxiliary Limit (Aux Limit 1) T7 = 1 or 0< ÈEA
Auxiliary Limit (Aux Limit 2) T8 = 1 or 0< ÈEA
Low water Cutoff (LWCO) T9 = 1 or 0< ÈEA
High Limit (High Limit) T10 = 1 or 0< ÈEA
Auxiliary Limit (AuxLimit 3) T11 = 1 or 0< ÈEA
Oil Selection Switch (Oil Select) T12 = 1 or 0< ÈEA
High Oil Pressure Switch (Hi OilPres) T13 = 1 or 0< ÈEA
Low Oil Pressure Switch
(LowOilPres)
T14 = 1 or 0< ÈEA
High Oil Temperature Switch (Hi
OilTemp)
T15 = 1 or 0< ÈEA
Low Oil Temperature Switch
(LowOilTemp)
T16 = 1 or 0< ÈEA
Atomizing Switch (Atomize Sw) T19 = 1 or 0 ÈEA
Gas Selection Switch (Gas Select) T17 = 1 or 0< ÈEA
High Gas Pressure Switch (Hi
GasPres)
T18 = 1 or 0< ÈEA
Low Gas Pressure Switch
(LowGasPres)
T19 = 1 or 0< ÈEA
Airflow Switch (Airflow Sw) T20 = 1 or 0< ÈEA
Auxiliary Interlock (Aux ILK 4) T21 = 1 or 0< ÈEA
Auxiliary Interlock (Aux ILK 5) T22 = 1 or 0< ÈEA
EA Fault Code nnn< ÈEA
Software Revision (SW Rev.) nnnn< ÈEA