| 7800 SERIES RELAY MODULES |
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Table 2. Keyboard Display Module Sequence and Status Hold Messages (continued). |
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Sequence | Status |
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If the relay module is in a PURGE HOLD status, the following conditions could exist (continued): |
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PURGE HOLD: T18 | The KDM indicates the burner status and that the Low Fire Switch is jumpered. The Low Fire |
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(Low Fire Switch | Switch is bypassed, welded or otherwise prematurely closed. The system automatically adds 30 |
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Jumpered) | seconds to allow the firing rate motor additional drive time to reach or near the closed damper |
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| position before starting the ignition sequence. |
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PURGE HOLD: F/G | The KDM indicates the burner status and that a flame is detected. The burner sequence does not |
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(Flame Detected) | advance through PREPURGE because a flame is detected as being present. The sequence holds |
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| waiting for the flame signal to clear. If the time exceeds 30 seconds, the relay module locks out. |
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PURGE HOLD: T18 | The KDM indicates the burner status and that the Low Fire Switch is not closed. The firing rate |
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(Low Fire Switch) | motor is driving to its Low Fire position in preparation for Ignition Trials. If this time exceeds four |
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| minutes and fifteen seconds, the relay module locks out. |
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PURGE HOLD: T7 | The KDM indicates the burner status and that the Running Interlock is not closed. The sequence |
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(Running Interlock) | does not advance to ignition until the Running Interlock proves closed. If this time exceeds 30 |
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| seconds, the relay module locks out. |
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PILOT IGN mm:ss | The KDM indicates the burner status, PILOT IGN, and the timing of the PILOT IGN trial begins, in |
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| seconds. During this period, the relay module permits the pilot valve to open and the pilot flame |
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| to establish. |
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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. |
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MAIN IGN mm:ss | The KDM indicates the burner status, MAIN IGN, and the timing of the MAIN IGN trial begins, in |
| seconds. During this period, the relay module permits the main valve to open and the main flame |
| to establish. |
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RUN | The KDM indicates the burner status, RUN, which is the period of time after the Ignition Trials and |
| before the operating controller setpoint is reached. During this time, the burner is firing under |
| control of the firing rate control. |
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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. |
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POSTPURGE mm:ss | The KDM indicates the burner status, POSTPURGE, which is the period of time after the RUN |
| period when the blower motor continues to run. The timing of the POSTPURGE period is fifteen |
| seconds. |
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Waiting for | The KDM has power but is waiting to receive a signal from the relay module to continue |
connection... | operation. |
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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 |
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Additional Sequence Status Information When An Expanded Annunciator Is Connected To The Relay Module: | |
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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. |
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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. |
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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. |
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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. |
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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.
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