Honeywell 7800 Series Manual page 9

Table 2. Keyboard Display Module Sequence and Status Hold Messages (continued).
Sequence
If the relay module is in a PURGE HOLD status, the following conditions could exist (continued) :
PURGE HOLD: T18 The KDM indicates the burner status and that the Low Fire Switch is jumpered. The Low Fire
(Low Fire Switch Switch is bypassed, welded or otherwise prematurely closed. The system automatically adds 30
Jumpered) seconds to allow the firing rate motor additional drive time to reach or near the closed damper
position before starting the ignition sequence.
PURGE HOLD: F/G The KDM indicates the burner status and that a flame is detected. The burner sequence does not
(Flame Detected) advance through PREPURGE because a flame is detected as being present. The sequence holds
waiting for the flame signal to clear. If the time exceeds 30 seconds, the relay module locks out.
PURGE HOLD: T18 The KDM indicates the burner status and that the Low Fire Switch is not closed. The firing rate
(Low Fire Switch) motor is driving to its Low Fire position in preparation for Ignition Trials. If this time exceeds four
minutes and fifteen seconds, the relay module locks out.
PURGE HOLD: T7 The KDM indicates the burner status and that the Running Interlock is not closed. The sequence
(Running Interlock) does not advance to ignition until the Running Interlock proves closed. If this time exceeds 30
seconds, the relay module locks out.
The KDM indicates the burner status, PILOT IGN, and the timing of the PILOT IGN trial begins, in
PILOT IGN mm:ss
seconds. During this period, the relay module permits the pilot valve to open and the pilot flame
to establish.
If the relay module is in a PILOT HOLD status, the following condition could exist:
PILOT HOLD: TEST The KDM indicates the burner status, PILOT IGN, and that the Run/Test Switch is in the TEST
(Run/Test Switch) position. The sequence does not continue until the Run/Test Switch is placed in the RUN
position.
The KDM indicates the burner status, MAIN IGN, and the timing of the MAIN IGN trial begins, in
MAIN IGN mm:ss
seconds. During this period, the relay module permits the main valve to open and the main flame
to establish.
The KDM indicates the burner status, RUN, which is the period of time after the Ignition Trials and
RUN
before the operating controller setpoint is reached. During this time, the burner is firing under
control of the firing rate control.
If the relay module is in a RUN HOLD status, the following condition could exist:
RUN LOWFIRE: TEST The KDM indicates the burner status and that the Run/Test Switch is in the TEST position.
(Run/Test Switch) Normal modulation or operation does not continue until the Run/Test Switch is placed in the RUN
position.
The KDM indicates the burner status, POSTPURGE, which is the period of time after the RUN
POSTPURGE mm:ss
period when the blower motor continues to run. The timing of the POSTPURGE period is fifteen
seconds.
Waiting for The KDM has power but is waiting to receive a signal from the relay module to continue
connection... operation.
RESET/ALARM TEST The KDM indicates the burner status, RESET/ALARM TEST. This condition indicates that the
reset button is pressed. If it is held for more than four seconds, the alarm output is energized. The
alarm output is de-energized when the reset button is released.
Additional Sequence Status Information When An Expanded Annunciator Is Connected To The Relay Module:
BURNER OFF: T6 The KDM indicates the Burner Switch is not closed. The burner sequence does not advance to
(Burner Switch) PREPURGE until the Burner Switch closes.
STANDBY The KDM indicates the burner status, STANDBY, and that the Operating Control is not closed.
The burner sequence does not advance to PREPURGE until the Operating Control closes.
STANDBY HOLD: T6 The KDM indicates the burner status, STANDBY, and that a limit is not closed. The burner
(EA Hold Message) sequence does not advance to PREPURGE until one or all limits close downstream from the
Operating Control.
STANDBY HOLD: T6 The KDM indicates the burner status, STANDBY, and that the control input is not closed. The
(Circuit Fault) burner sequence does not advance to PREPURGE until the control input closes.
NOTE: Normal sequences are in bold type, while abnormal sequences are in regular type. This table is for all 7800 SERIES
Relay Modules so all listed steps may not apply to the unit installed.
7800 SERIES RELAY MODULES
Status
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