Troubleshooting, System diagnostics, Diagnostic information index – 2nd Ave. Honeywell Relay Modules 7800 Series User Manual

Page 7: Historical information index

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6. Loss of flame during RUN.


Open the main fuel manual shutoff valve(s) and
open manual pilot shutoff valve(s).


Depress the RESET button.


Start the system. Start-up should be normal and
the main burner should light normally.


After the sequence is in the normal RUN period
for at least ten seconds with the main burner
firing, close the manual main fuel shutoff valve(s)
to extinguish the main burner flame. (On
intermittent pilot applications, also, close the pilot
manual shutoff valve.)


The flame signal should drop below 1.25 Vdc
within the FFRT of the amplifier and the relay
module after the main flame and/or pilot goes out.


*Main Flame Fail* fault is displayed on the
Keyboard Display Module. Fault code 17 is
displayed to denote the fault.


Safety shutdown occurs. (EC/RM7890, EC/
RM7895, RM7896 relay modules will recycle if
jumper JR2 is intact, then lock out on failure to
light the pilot.)

7. Opening a Preignition Interlock after the first five

seconds of POSTPURGE.


Open the main fuel manual shutoff valve(s) and
open manual pilot shutoff valve(s).


Depress the RESET button.


*Preignition ILK* fault is displayed on the
Keyboard Display Module. Fault code 33 is
displayed to denote the fault.


Safety shutdown occurs.



If the relay module fails to shut down on any of
these tests, take corrective action; refer to
Troubleshooting and the relay module diagnostics
and return to the beginning of all Checkout tests.


When all Checkout tests are completed, reset all
switches to the original status.


System Diagnostics

Troubleshooting control system equipment failures is easier
with the relay module self-diagnostics and first-out
annunciation. In addition to an isolated spst alarm relay
(audible annunciation), the relay module provides visual
annunciation by displaying a fault code and fault or hold
message at the S7800 Keyboard Display Module (standard
on RM7800 and RM7838A,B devices; optional on all others).
The relay module provides 127 diagnostic messages for
troubleshooting the system (see Table 3).

Self-diagnostics of the relay module enables it to detect and
annunciate both external and internal system problems. Fault
messages, such as interlock failures, flame failures and false
flame signals are displayed at the KDM, and annunciated at
the 7800 SERIES Relay Module by the ALARM LED.

The KDM displays a sequence status message indicating:
POSTPURGE. 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 2 provides the sequence and status hold messages.
Table 3 is a summary of all relay module fault messages, fault
codes, and troubleshooting suggestions. In addition,
Diagnostic Information and History Data are available to
assist in troubleshooting the relay module.

The relay module provides diagnostic information to aid the
service mechanic in obtaining information when
troubleshooting the system. Information available in the
Diagnostic Information includes Device Type, Device Suffix,
Software Revision, Manufacturing Code, Flame Amplifier
Type, Flame Failure Response Time, Selectable Jumper
Configuration Status, Run/Test Switch Status and Terminal

Diagnostic Information Index

The relay module monitors input/output terminals and can
display the status of the terminal at the KDM (see Table 2)
(example: Pilot Valve T8 1). See the applicable relay module
installation instructions for a complete terminal description
and number. The display shows the actual status of the
terminal. If voltage is detected at the terminal, 1 is displayed,
but if no voltage is detected at the terminal, 0 is displayed.

Historical Information Index

The relay module has nonvolatile memory that allows the
Relay Module to retain historical information for the six most
recent lockouts. Each of the six lockout files retains the cycle
when the fault occurred, the hour of operation when the fault
occurred, a fault code, a fault message and burner status
when the fault occurred.


Some older relay modules can not operate without a
KDM, extension cable assembly with KDM or a Data
ControlBus Module™ installed.


1. If the KDM is scrambled, remove and reinstall the

KDM, and reset the 7800 Relay Module.

2. Reset the 7800 Series Relay Module by pressing the

RESET pushbutton on the 7800 Series Relay
Module, or pressing a remote reset pushbutton wired
through the KDM, Data ControlBus Module™ or
Remote Reset Module. A power-up reset causes an
electrical reset of the relay module but does not
reset a lockout condition.

3. Use the access slots on the sides of the Q7800A,B

to check terminal voltage.

4. Maximum ambient operating temperature of a

C7012E,F; Series 1 through 6, is reduced to


F because of the duty cycle operation of the

relay module.