Safety Provisions - Honeywell 7800 Series Manual

h. Ignition terminal is energized after the first ten sec-
onds of PFEP.
i. Flame Proven terminal is energized for the first ten sec-
onds of PFEP.
j. Flame Proven terminal is not energized at the end of
PFEP.
k. Special Function 2 is not energized after eight min-
utes (Pilot Configuration).
3. MAIN FLAME ESTABLISHING Period.
a. Pilot is energized.
b. Pilot/1st stage main valve terminal is not energized.
c. Main valve terminal is not energized.
d. No flame present.
e. Internal system fault.
f. @Low Fire switch is not energized.
g. Ignition terminal is energized.
h. Flame Proven is not energized.
i. Limits Complete is not energized.
j. Special Function 2 is not energized.
k. Special Function 3 is not energized.
4. RUN Period
a. No flame present.
b. Flame Proven is not energized.
c. Internal system fault.
d. Ignition terminal is energized.
e. Pilot terminal is energized (Pilot configuration).
f. Pilot terminal/main valve first stage is not energized
(DSI configuration).
INTERNAL HARDWARE STATUS MONITORING
The RM7888A analyzes the integrity of the configura-
tion jumper and internal hardware. The POWER LED
blinks every four seconds to signify an internal hardware
check.
CLOSED LOOP LOGIC TEST
The test verifies the integrity of all safety critical loads
(terminals 8, 9, 10 and 21). If the loads are not energized
properly, for example, the main valve terminal is powered
during purge, the RM7888A will lockout on a safety shut-
down. The RM7888A must react to input changes but avoid
the occurrence of nuisance shutdown events. Signal con-
ditioning is applied to line voltage inputs to verify proper
op-eration in the presence of normal electrical line noise
such as transient high voltage spikes or short periods of line
dropout. Signal conditioning is tolerant of synchronous
noise (line noise events that occur at the same time during
each line cycle).
DYNAMIC FLAME AMPLIFIER AND SHUTTER
CHECK
Self-checking circuitry tests all electronic components in
the flame detection system and amplifier 12 times per minute
and shuts down the RM7888A if the detection system fails.
PRINCIPAL TECHNICAL FEATURES • SAFETY PROVISIONS
g. Limits Complete is not energized.
h. Main valve is not energized.
5. Anytime the configuration jumpers are changed while
the RM7888A is powered.
6. PILOT RELIGHT
a. Limits Complete is de-energized.
b. Special Function 2 is not energized.
c. Special Function 3 is not energized.
d. Ignition, pilot, or main is not energized.
e. Low Fire is not energized.
f. Flame failure.
g. Ignition terminal not energized.
h. Flame Proven is not energized.
7. WAIT FOR LOW OFF FOR 5 SECONDS
a. Limits Complete is not energized.
b. Special Function 2 is not energized.
c. Flame failure.
d. Ignition energized.
e. Main energized.
f. Flame Proven not energized.
g. Pilot not energized.
8. DRIVE TO LOW
a. Limits Complete is not energized.
b. Special Function 2 is not energized
c. Flame failure.
d. Ignition energized.
e. Main energized.
f. Flame Proven is not energized.

Safety Provisions

DYNAMIC AMPLICHECK™
Dynamic Amplicheck™ circuitry tests the flame signal
amplifier during burner operation and shuts down RM7888A
if the flame amplifier fails.
DYNAMIC INPUT CHECK
All system input circuits are examined to make sure that
the RM7888A is capable of recognizing the true status of
external controls, limits and interlocks. If any input fails this
test, a safety shutdown occurs and the fault is annunciated.
DYNAMIC SAFETY RELAY TEST
Checks the ability of the dynamic safety relay contacts
to open and close. Verifies that the safety critical loads (ter-
minals 8, 9, 10 and 21) can be de-energized, as required, by
the Dynamic Self-Check logic.
DYNAMIC SELF-CHECK SAFETY CIRCUIT
The microcomputer tests itself and related hardware, and
at the same time, the safety relay system tests the microcom-
puter operation. If a microcomputer or safety relay failure
occurs and does not allow proper execution of the self-check
routine, safety shutdown occurs and all safety critical loads
will be de-energized.
9
RM7888A
65-0175