Installation And Wiring - Honeywell 7800 Series Manual

First-Out Annunciation and
Self-Diagnostics
Sequence Status Lights (LEDs) provide positive visual
indication of the program sequence: POWER, PILOT,
FLAME, MAIN and ALARM. The green POWER LED blinks
every four seconds to signify the RM7830A or RM7850A
hardware is running correctly.
Multi-function Keyboard Display Module shows elapsed time
during PURGE, PREIGNITION, SAFETY 1, PILOT STAB.,
MAIN TRIAL, and POSTPURGE. As an additional
troubleshooting aid, it provides sequence timing, diagnostic
information, and historical information when a safety
shutdown or hold or normal operation occurs.
First-out Annunciation reports the cause of a safety shutdown
or identifies the cause of a failure to start or continue the
burner control sequence with a text description and
numbered code via the Keyboard Display Module. It monitors
all field input circuits, including the Flame Signal Amplifier and
Firing Rate Position Switches. The system distinguishes 61
modes of failure and detects and annunciates difficult-to-find
intermittent failures.
Self-Diagnostics adds to the First-out Annunciation by
allowing the RM7830A or RM7850A to distinguish between
field (external device) and internal (system related) problems.
Faults associated within the flame detection subsystem, the
Relay Module, or plug-in Purge Card, are isolated and
reported by the Keyboard Display Module; see the
Troubleshooting section.
Interlock Requirements
The following interlock inputs are provided:
Low Fire Switch Input (RM7850A)
This interlock (ES1) verifies the firing rate motor is in the low
fire position before and during ignition trials.
High Fire Switch Input (RM7850A)
This interlock (ES3) verifies the firing rate motor is in the high
fire position prior to and during PURGE.
Airflow Switch Input
This interlock verifies that there is airflow to the burner. If the
Airflow Switch Input (LD2) is open for more than ten seconds
into PURGE, the RM7830A or RM7850A will lockout. After
entering PURGE, if the Airflow Switch Input opens during the
first ten seconds, the purge timer will be reset. This provides
a continuous PURGE to occur without interruption before the
Ignition Trials. If the Air-flow Switch input opens anytime after
ten seconds into PURGE, during the Ignition Trials or Run, it
causes a lockout. The Airflow Switch is a site configurable
option (see Table 6). If the Airflow Switch is disabled, then a
jumper must be installed between Terminals 6 and 7. If the
Airflow Switch is enabled, the RM7830A or RM7850A will
lockout if it detects a short or jumper between Terminals 6
and 7.
Lockout Input
This interlock (LOS) input signifies a Lockout Interlock. The
RM7830A or RM7850A will lockout anytime the Lock-out
Input String opens.
7800 SERIES RM7830A, RM7850A RELAY MODULE
Preignition Interlock
The Preignition Interlock input (ES2) is typically connected to
proof-of-closure switches for fuel valve(s). The Preignition
Interlock must be energized throughout PURGE and
PREIGNITION. If the Preignition Interlock opens during
STANDBY, it causes a hold (30 seconds). The RM7830A or
RM7850A will lockout if the interlock does not close within 30
seconds during STANDBY. If the Preignition Interlock opens
during PURGE or PREIGNITION, it will lockout. The
Preignition Interlock is ignored during ignition trials,
POSTPURGE, and during RUN.

INSTALLATION AND WIRING

Installation
CAUTION
1. Disconnect the power supply before beginning
installation to prevent electrical shock, equipment
and control damage. More than one power supply
disconnect may be involved.
2. Wiring connections for the Relay Module are
unique; therefore, refer to Figs. 3, 4, 5, or 6 or the
correct Specifications for proper subbase wiring.
3. Wiring must comply with all applicable codes,
ordinances and regulations.
4. Loads connected to the Relay Module must not
exceed those listed on the Relay Module label or
the Specifications, see Table 1.
5. Limits and interlocks must be rated to
simultaneously carry and break current to the
ignition transformer, pilot valve, and main fuel
valve(s).
6. All external timers must be listed or component
recognized by authorities who have jurisdiction
for the specific purpose for which they are used.
IMPORTANT
1. In order to meet EN60730, the Relay Module has to
be mounted in a secured panel which meets IP 40
class of protection.
2. For on-off gas-fired systems, some authorities who
have jurisdiction prohibit the wiring of any limit or
operating contacts in series between the flame
safeguard control and the main fuel valve(s).
3. Two Flame Detectors can be connected in parallel.
Humidity
Install the Relay Module where the relative humidity never
reaches the saturation point. The Relay Module is designed
to operate in a maximum 85% RH continuous,
noncondensing, moisture environment. Condensing moisture
may cause a safety shutdown.
Vibration
Do not install the Relay Module where it could be subjected to
in excess of 0.5G continuous maximum vibration.
Weather
The Relay Module is not designed to be weather tight. If
installed outdoors, the Relay Module must be protected by an
approved weather-tight enclosure.
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