Ignition Cable; Grounding Connections - Honeywell S8700 Series Installation Instructions Manual

START
CALL FOR HEAT (24 VAC INPUT TO 24 VAC TERMINAL).
SAFE START
SAFE START CHECK. FLAME DETECTED?
CHECK/
(LED BLINKS RAPIDLY).
PREPURGE
PREPURGE (L AND M MODELS).
TRIAL FOR
SPARK GENERATOR POWERED; MAIN VALVE OPENS.
IGNITION
MAIN BURNER LIGHTS AND FLAME SENSED
DURING TRIAL FOR IGNITION?
MAIN
BURNER NORMAL MAIN BURNER OPERATION.
OPERATION
FLAME SIGNAL LOST?
CALL FOR HEAT ENDS (24 VAC INPUT REMOVED
FROM 24 VAC TERMINAL).
MAIN BURNER OFF.
END
NOTES:
— WHEN CONTROL IS IN LOCKOUT, ALARM OUTPUT (IF PROVIDED) IS ENERGIZED.
— LED FLASHES AT HEARTBEAT SPEED DURING ALL NORMAL OPERATION.
WARNING
High Voltage Hazard.
Shock can cause personal injury.
To prevent electric shock, do not allow fingers to
touch the stripped end of the jumper or the
spark terminal.
4. Perform this test immediately upon energizing the
system, before the S8700 goes into lockout and
interrupts the spark circuit. Touch one end of the
jumper firmly to the S8700 GND terminal. Do not
remove the existing ground lead. Slowly move the
other end of the jumper wire toward the spark ter-
minal on the control to establish a spark. Pull the
wire away from the spark terminal and note the
length of the gap at which the spark discontinues.
5. A spark length of 1/8 in. (3 mm) or more indicates
satisfactory voltage output. If no arc can be
established or the maximum spark is less than 1/8
in. (3 mm) and power to the S8700 input terminals
was proved, replace the S8700.

Ignition Cable

Check the electrical continuity of the ignition cable and
make certain that the cable is not in contact with metal
surfaces. The total cable length should not exceed 6 ft
(1.8m). Check connection to the spark terminal on the
S8700 and the boot connection to the igniter/sensor.
Make certain they are clean and tight.
NO
YES
NO
Fig. 5. S8700E,F,L,M retry sequence of operation.
S8700B,D-F,J-M DIRECT SPARK IGNITION CONTROLS
1 HOUR AUTO RESET TIME.
WAIT 4 SEC. FLAME
YES
STILL DETECTED?
NO
30 SEC. BETWEEN
TRIAL PURGE.
NO
MAIN VALVE STAYS OPEN;
YES
SPARK GENERATOR POWERED.
MAIN BURNER LIGHTS AND FLAME
SENSED DURING TRIAL FOR IGNITION?
NO

Grounding Connections

A common ground is required for the main burner, spark
igniter mounting bracket or igniter sensor mounting
bracket, and the GND (burner) terminal of the S8700. If
the common ground connections are poor or erratic,
safety shutdown can occur occasionally even though
operation is normal at time of checkout. Therefore, if
nuisance shutdowns have been reported, be sure to
check ground connections.
Electrical ground connections at the spark igniter or
igniter sensor and the S8700 must be clean and tight. If
leadwire is damaged or deteriorated, use only a No. 14
or No. 18 gauge, moisture resistant, thermoplastic
insulated wire with 221°F (105°C) minimum rating as a
replacement.
Flame Sensor Circuit
The S8700 provides ac voltage to the flame sensor.
When a flame of sufficient size is present, the ac
voltage is rectified and sensed as a dc flame current by
the S8700. The S8700 will operate with a steady 1.0 µA
dc flame current. However, reliable appliance operation
requires at least 2.0 µA flame current (measured with
an analog dc microammeter during worst case appli-
ance checkout.).
7
LOCKOUT WITH
YES
LED ON STEADY.
NO
RETRY COUNT
YES
LESS THAN 2?
MAIN VALVE CLOSES;
SPARK GENERATOR OFF.
LOCKOUT WITH LED ON STEADY
YES
M16530
69-1299