Product Overview
Table Of Contents
- Application
- Features
- Optional Features
- Specifications
- Principal Technical Features
- Safety Provisions
- Internal Hardware Status Monitoring
- Closed Loop Logic Test
- Dynamic AMPLI-CHECKTM Circuitry
- Dynamic Input Check
- Dynamic Safety Relay Test
- Dynamic Self-Check Safety Circuit
- Expanded Safe-Start Check
- Off Cycle (Standby) Flame Signal Check
- Tamper Resistant Timing and Logic
- Verified Spark Termination
- First-Out Annunciation and Self- Diagnostics
- Interlock Requirements (RM7895 Only)
- Installation
- Wiring
- Assembly
- Operation
- Initiate
- Standby
- Static Checkout
- Checkout
- Equipment Recommended
- Checkout Summary
- Preliminary Inspection
- Flame Signal Measurement
- Initial Lightoff Check for Proved Pilot
- Initial Lightoff Check for Direct Spark Ignition (DSI)
- Pilot Turndown Test (All Installations Using a Pilot)
- Ignition Interference Test (All Flame Rods)
- To Eliminate Ignition Interference
- Flame Signal with Hot Combustion Chamber (All Installations)
- Safety Shutdown Tests (All Installations)
- Troubleshooting
RM7890; RM7895 100 VAC 7800 SERIES RELAY MODULES
66-1195—01 26
SERVICE NOTE:
A lockout condition or restart of a relay module can be
accomplished by pressing the reset pushbutton on the
relay module or by pressing a remote reset pushbutton
wired through an optional KDM, Data ControlBus™
Module, extension cable assembly, or remote reset
module. A power-up reset module causes an electrical
reset of the relay module but does not reset a lockout
condition.
SERVICE NOTE:
Remove the access slot covers on the sides of the Q7800
Wiring Subbase to check voltages.
WARNING
Electrical Shock Hazard.
Can cause severe injury, death or property
damage.
Replace access slot covers on the Q7800B Wiring
Subbase after performing voltage checks.
NOTE: Normal sequences are in bold type, while abnormal sequences are in regular type.
Table 13. Sequence and Status Hold Information.
Sequence Information
INITIATE The LED indicates the burner status, POWER, which is a stabilization period for the relay module to
check for any fluctuations in ac ling 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 relay is in a HOLD status, the following conditions can exist:
INITIATE HOLD:
(AC Frequency/Noise)
The LED indicates the burner status, POWER, and that the relay module is waiting for excess line
noise to clear up. The burner sequence will 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
detected.
INITIATE HOLD:
(AC Line Dropout)
The LED indicates the burner status, POWER, and that ac line power has momentarily dropped out.
The burner sequence will not advance into STANDBY until the ac line voltage has stabilized
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 will 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 will 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 setpoint has been satisfied. If a demand
is present for burner operation, the burner sequence will not advance from STANDBY until the
recycle limit closes.
If the relay module is in a HOLD status, the following conditions could exist:
PURGE (RM7895 only) 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.
PURGE HOLD: F/G
(Flame Detected)
(RM7895 Only)
The LED indicates the burner status, POWER and FLAME, and that a flame is detected. The burner
sequence will not advance through PREPURGE because a flame is detected as being present. The
sequence will hold waiting for the flame signal to clear. If the time exceeds 30 seconds, the relay
module will lockout.
PURGE HOLD: T7 (Airflow
Interlock) (RM7895 Only)
The LED indicates the burner status, POWER, and that the Airflow Interlock is not closed. The
sequence will not advance into ignition until the Airflow Interlock proves closed. If this time exceeds
a 30-second HOLD, the relay module will lockout.
STANDBY HOLD: F/G
(Flame Detected)
The LED indicates the burner status, POWER and FLAME, and that a flame is detected. A demand
is present for burner operation. The burner sequence will not advance to SAFE START CHECK
(PREPURGE in the RM7895) because a flame is detected as being present. The sequence will not
advance to SAFE START CHECK until the flame signal clears. If the flame signal does not clear
within 40 seconds, the relay module will lockout.
SAFE START CHECK
(RM7890 Only)
The LED indicates the burner status, POWER, which is the period of time after STANDBY. The
RM7890 is verifying that a flame is not present before the start of Ignition Trials. If a flame is present,
the RM7890 will recycle to STANDBY.