Installation - Honeywell 7800 Series Manual

RM7838B
SAFETY PROVISIONS • INSTALLATION
Multi-function Keyboard Display Module shows elapsed
time during PURGE, PILOT IGN, and MAIN IGN. As an
additional troubleshooting aid, it provides sequence timing,
diagnostic information, historical information and expanded
annunciator 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 con-
tinue the burner control sequence with an English text and
numbered code via the Keyboard Display Module. And it
monitors all field input circuits, including the Flame Signal
Amplifier and Firing Rate Position Switches. The system
distinguishes 63 modes of failure and detects and annunci-
ates difficult to find intermittent failures.
Self Diagnostics adds to the First-out Annunciation by
allowing the RM7838B to distinguish between field (exter-
nal device) and internal (system related) problems. Faults
associated within the flame detection subsystem, RM7838B
or plug-in Purge Card, are isolated and reported by the
Keyboard Display Module. See Table 12, Hold and Fault
Message Summary, or the 7800 SERIES Service Handbook,
form 65-0111.
INTERLOCK REQUIREMENTS
The following interlock inputs are provided:
LOCKOUT INTERLOCK (ILK) (TERMINAL NO. 7)
The Lockout Interlock (ILK) is typically the Combustion
Air Blower Switch. If the Lockout Interlock is de-energized
WHEN INSTALLING THIS PRODUCT...
1. Read these instructions carefully. Failure to follow
them could damage the product or cause a hazardous
condition.
2. Check the ratings given in the instructions and on
the product to make sure the product is suitable for the
application.
3. Installer must be a trained, experienced, flame safe-
guard control technician.
4. After installation is complete, check out the product
operation as provided in these instructions.
65-0120—1
five seconds after the combustion air Blower is turned on or
anytime during ignition trials or run, a Lockout occurs.
NOTE: The five second timing does not begin for the
RM7838B until the low fire proving switch is closed at
the end of PURGE and the RM7838B turns on termi-
nal 5, starting the Combustion Air Blower.
Low Fire Interlock (Terminal No. 18)
This interlock verifies the firing rate motor is in the low
fire position before and during ignition trials.
High Purge Rate Interlock (Terminal No. 19)
This interlock verifies the firing rate motor is in the high
purge rate position prior to and during PURGE.
Preignition Interlock (Terminal No. 20)
The Preignition Interlock input is typically connected to
proof-of-closure switches for fuel valve(s). The Preignition
Interlock must be energized throughout STANDBY and
PURGE. If Preignition Interlock opens during STANDBY,
it causes a hold and will lockout if the interlock does not close
within 30 seconds. If the Preignition Interlock opens during
PURGE, the RM7838B will lockout. If the Preignition Inter-
lock is open after five seconds into STANDBY (after the stop
button is pushed), the RM7838B will lockout. The Preignition
Interlock is ignored during the ignition trials state during
RUN, and Pilot Valve Hold.
CAUTION
1. Disconnect the power supply before beginning
installation to prevent electrical shock and equip-
ment damage. More than one power supply
disconnect may be involved.
2. Wiring connections for the RM7838B are unique;
therefore, refer to Fig. 7 or the correct Specifica-
tions for proper subbase wiring.
3. Wiring must comply with all applicable codes,
ordinances and regulations.
4. Wiring, where required, must comply with NEC
Class 1 (Line Voltage) wiring.
5. Loads connected to the RM7838B must not
exceed those listed on the RM7838B label or the
Specifications, see Table 1.
6. Limits and interlocks must be rated to simulta-
neously carry and break current to the ignition
transformer, pilot valve, and main fuel valve(s).
7. All external timers must be listed or component
recognized by authorities who have jurisdiction
for the specific purpose for which they are used.
12

Installation