Troubleshooting - Honeywell 7800 Series Manual

RM7823A SYSTEM DIAGNOSTICS
Troubleshooting control system equipment failures is
easier with the RM7823A self-diagnostics. The RM7823A
provides visual annunciation of internal faults (detection
system failure with AMPLI-CHECK or Shutter Check sys-
tems) by displaying the ALARM LED.
Self-diagnostics of the RM7823A enable it to detect and
annunciate internal system problems with an ALARM LED.
The RM7823A provides diagnostic information (acces-
sible by the optional Keyboard Display Module) to aid the
service mechanic to obtain information when troubleshoot-
ing the system, see Table 6.
The optional Keyboard Display Module displays se-
quence status messages indicating: STANDBY and RUN.
The selectable messages also provide visual indication, cur-
rent status and historical status of the equipment such as:
Flame Signal, Total Cycles, Total Hours, Fault History,
Diagnostic Information and Expanded Annunciator Termi-
nal Status (if used). With this information, most problems can
be diagnosed without extensive trial and error testing. Infor-
mation available in the Diagnostic Information file includes:
Device Type, Device Suffix, Software Revision, Manufac-
turing Code, Flame Amplifier Type, and Flame Failure
Response Time.
DIAGNOSTIC INFORMATION INDEX
The RM7823A with the optional Keyboard Display Mod-
ule can monitor and display flame signal strength at the VFD,
see S7800A1001 Keyboard Display Module Specifications.
TABLE 6—SEQUENCE AND STATUS HOLD INFORMATION.
Sequence
NOTE: Normal sequences are in bold type, while abnormal sequences are not in bold type.
STANDBY
If the RM7823A is in a HOLD status, the following conditions could exist:
RUN
INITIATE
If the RM7823A is in a HOLD status, the following conditions could exist:
INITIATE HOLD: (AC Frequency/Noise)
HISTORICAL INFORMATION INDEX
The RM7823A 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, and the fault message when the fault
occurred. The Historical Information can be viewed by the
optional S7800A1001 Keyboard Display Module.
SERVICE NOTE: A Lockout condition or restart of a
RM7823A can be accomplished by pressing the reset
pushbutton on the RM7823A, or by pressing a remote
reset pushbutton wired through an optional Keyboard
Display Module, DATA CONTROLBUS MODULE™
or Remote Reset Module. A power-up reset will cause
an electrical reset of the RM7823A but will not reset a
lockout condition.
SERVICE NOTE: Remove the access slot covers on the
sides of the Q7800A,B to check voltages.
! CAUTION
Reinstall access slot covers on the Q7800A,B Sub-
base after performing voltage checks.
SERVICE NOTE: Maximum ambient operating tem-
perature of a C7012E,F Series 1 through 6 will be
reduced to 125° F because of the duty cycle operation of
the RM7823A Relay Module.
Information
The LED indicates the system status, POWER. The RM7823A remains
in STANDBY until a flame or flame simulating condition is present.
The LEDs indicate the system status, POWER, and FLAME, which is
the period of time flame is detected by the RM7823A. During this
time, the burner is firing under the control of the operating controller.
The LED indicates the burner status, POWER, which is a stabilization
period for the RM7823A to check for any fluctuations in AC line voltage
inputs during normal operation. The minimum timing of INITIATE
period is ten seconds but if the problem exists for four minutes the
Alarm LED will be turned on.
The LED indicates the burner status, POWER, and that it is waiting for
excess line noise to clear up. The RM7823A sequence will not advance
into RUN until the excess line noise, which prevents sufficient reading
of the line voltage inputs, ceases or a line frequency error (perhaps
caused by using a 60 Hz device on a 50 Hz line, or vice versa) is
corrected.
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TROUBLESHOOTING

Troubleshooting
RM7823A
(continued)
65-0106—2