Honeywell RM7895A Thermostat User Manual


 
7800 SERIES EC7895A, RM7895A RELAY MODULE
65-0205
27
Table 6. Sequence And Status Hold Information.
NOTE: Normal sequences are in bold type, while abnormal sequences are not in bold type.
Sequence Status
INITIATE The LED indicates the burner status, POWER, which is a stabilization period
for the RM7895 to check for any fluctuations in AC line voltage inputs or
control input on power-up or during normal operation. The timing of the
INITIATE period is ten seconds before entering STANDBY.
If the EC7895 or RM7895 is in a HOLD status, the following conditions could exist:
INITIATE HOLD: (AC Frequency/Noise) The LED indicates the burner status, POWER, and that it is waiting for
excess line noise to clear up. The burner sequence does not advance into
STANDBY until the excess line noise, which prevents sufficient reading of
the line voltage inputs, ceases or a line frequency error is corrected.
INITIATE HOLD: (AC Line Dropout) The LED indicates the burner status, POWER, and that AC Line power has
momentarily dropped out. The burner sequence does not advance into
STANDBY until the AC line voltage stabilizes throughout the INITIATE
sequence.
INITIATE HOLD: (AC Frequency) The LED indicates the burner status, POWER, and that line frequency is
faster than the expected value. The burner sequence does not advance into
STANDBY until the line frequency returns to the proper value.
INITIATE HOLD: (Low Line Voltage) The LED indicates the burner status, POWER, and that low line voltage has
occurred. The burner sequence does not advance into STANDBY until the
line voltage is at a sufficient level for proper operating parameters.
STANDBY The LED indicates the burner status, POWER. The burner can be placed in
STANDBY by opening the burner switch or if the operating controller
indicates its set point is satisfied. If a demand is present for burner
operation, the burner sequence does not advance from STANDBY to
PURGE until the recycle limits close.
If the EC7895 or RM7895 is in a HOLD status, the following conditions could exist:
STANDBY HOLD: F/G (Flame Detected) The LEDs indicate the burner status, POWER and FLAME, and that a flame
is detected. A demand is present for burner operation. The burner sequence
does not advance to PREPURGE because a flame is detected as being
present. The sequence does not advance to PREPURGE until the flame
signal clears. If the flame signal does not clear within 40 seconds, the
RM7895 locks out.
STANDBY HOLD: T7 (Airflow Interlock) The LED indicates the burner status, POWER, and that the Air-flow Interlock
is closed. A demand is present for burner operation and the burner
sequence does not advance to PREPURGE until the Airflow Interlock
proves open.
PURGE The LED indicates the burner status, POWER, and that it is the period of
time before ignition during which time the blower motor is running. The
timing of the PURGE period is selectable.