7800 SERIES RM7824A Relay Module
IMPORTANT
1. If the RM7824A fails to shut down on any of these tests, take corrective action (refer
to Troubleshooting, RM7824A diagnostics and return to the beginning of all Checkout
tests).
2. When all Checkout tests have been completed, reset all switches to original states.
TROUBLESHOOTING
RM7824A System Diagnostics
Troubleshooting control system equipment
failures is easier with the RM7824A self-diagnostics and first-out annunciation. In
addition to an isolated spst alarm relay (audible annunciation), the RM7824A provides
visual annunciation by displaying the ALARM LED.
Self-diagnostics of the RM7824A enable it
to detect and annunciate both external and internal system problems. External faults
such as flame failures and false flame signals are annunciated by a lockout of the RM7824A
that energizes the ALARM LEDs by using the optional Keyboard Display Module or 7800 SERIES
System Annunciation Diagnostics and Troubleshooting, form 65-0118.
The RM7824A provides diagnostic information to aid the service mechanic to obtain
information when troubleshooting the system; see Table 7 and Table 8.
The optional Keyboard Display Module
displays sequence status messages indicating: INITIATE, STANDBY, SAFE-START CHECK, PILOT
IGN and RUN. The selectable messages also provide visual indication, current status and
historical status of the equipment such as: Flame Signal, Total Cycles, Total Hours, Fault
History and Diagnostic Information.
The Expanded Annunciator Terminal Status is
not available with the RM7824A. With this information, most problems can be diagnosed
without extensive trial and error testing. Information available in the Diagnostic
Information file includes: Device Type, Device Suffix, Software Revision, Manufacturing
Code, Flame Amplifier Type, Flame Failure Response Time, Selectable Jumper Configuration
Status and Terminal Status.
Diagnostic Information Index
The RM7824A with the optional Keyboard Display
Module can monitor input/output terminals and can display the status of the terminal at
the VFD (eg, Pilot Valve T9 ON<), see S7800A Keyboard Display Module Specifications. A
complete terminal description and terminal number are provided. The display will show the
actual status of the terminal. If voltage is detected at the terminal, ON is displayed;
but if voltage is not present at the terminal, OFF is displayed.
Historical Information
The RM7824A 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 and burner status when the fault occurred.
The historical information can be viewed by the optional S7800A Keyboard Display Module.
SERVICE NOTE: To check voltages, remove
the access slot covers on the sides of the Q7800A,B.
! CAUTION
Reinstall access slot covers on the
Q7800A,B Subbase after performing voltage checks.
Table 7. Sequence And Status Hold
Information.
NOTE: Normal sequences are in bold
type, while abnormal sequences are in standard type.
Table 7. Sequence And Status Hold Information
Table 8. Hold And Fault Message Summary.
Helping You Control Your World
Home and Building Control
Honeywell Inc.
Honeywell Plaza
P.O. Box 524
Minneapolis, Minnesota 55408-0524Honeywell
Latin American Region
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Suite 200
Sunrise, FL 33325
Home Building Control
Honeywell Limited - Honeywell Limitée
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Honeywell Europe S.A.
3 Avenue du Bourget
B-1140 Brussels
Belgium
Honeywell Asia Pacific Inc.
Room 3213-3225
Sun Hung Kai Centre
No. 30 Harbour Road
Wanchai, Hong Kong |
Copyright © 1995 Honeywell Inc.
All Rights Reserved
Rev. 6-95 G.R. |
65-0155-1 |
