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69-1174
4
S8701/S8702 DIRECT SPARK IGNITION CONTROLS
Fig. 3. S8702 Wiring Diagram.
Grounding the S8701/S8702 Spark Igniter and
Main Burner
For the system to operate properly, spark igniter, flame
sensor bracket, the burner (GND) terminal on the 24V
(GND) terminal, and the S8701/S8702 control must share
a common ground with the main burner. Use thermoplastic
insulated wire with a minimum rating of 105°C (221°F) for
the ground wire; asbestos insulation is not acceptable. If
necessary, use a shield to protect the wire from radiant
heat generated by the burner.
IMPORTANT
Use moisture resistant 18 AWG wire rated for
continuous duty up to 105
°
C (221
°
F). Connec-
tions must be clean and tight.
Connect the ground wire as follows:
1. Fit one end of the ground wire with a female 1/4 in.
quick-connect terminal and connect it to the male
quick connect GND (Burner) terminal on the S8701/
S8702 control.
2. Strip the other end of the GND (Burner) wire and
fasten it under the igniter bracket mounting screw. If
necessary, use a shield to protect the wire from
radiant heat. The burner serves as the common
grounding area.
3. Fit one end of another ground wire with a female 1/4
in. quick connect terminal and connect it to the male
quick connect 24V (GND) terminal on the S8701/
S8702 control.
4. Strip the other end of the 24V (GND) wire and fasten
it to the burner ground.
5. If used with a separate flame sensor, make sure the
bracket is connected to the burner ground.
NOTE: It is not necessary that the burner is earth
grounded.
STARTUP AND CHECKOUT
The following start-up and checkout procedures are basic
to all S8701 and S8702 control modules. If this is a
replacement application, refer to the specific instructions
provided by the heating appliance manufacturer (if
available). Also, since the auxiliary controls used on any
DSI system may differ, refer to the manufacturer’s
instructions for start-up and checkout procedures for other
system components.
NOTE: If one of the system components fail, the S8701/
S8702 will either not operate or it will go into
safety lockout (depending on the type of failure).
If the system does not perform as outlined in
Start System and Check Trial for Ignition steps
below, refer to the SERVICE section to deter-
mine the cause.
Gas Leak Test
If the gas control has been replaced as a part of the S8701
or S8702 installation, perform the following test for gas
leaks.
WARNING
Fire or Explosion Hazard.
Can cause property damage, severe injury
or death.
To avoid possible explosion or fire, perform Gas
Leak Test.
With the main burner in operation, paint the pipe joints and
valve gasket with a rich soap and water solution. Bubbles
indicate a gas leak. To stop leak, tighten joints and screws or
replace the gasket. Never use a flame to check for gas leaks.
START SYSTEM
1. Turn on the power and the gas supply.
Set the temperature control to request heat and
watch for a spark at the igniter (S8701D, S8702D
models have no delay on start-up. S8702K and M
models have a predetermined delay on start-up for
prepurge.). Time the length of the spark operation; it
must be within the Trial for Ignition (TFI) timing
period (see Table 6).
2. Check that the system starts as follows: Spark turns
on, gas valve opens at once, and burner ignites after
gas reaches main burner. Once burner flame is
established, spark igniter cuts off. For S8702
models; flame must be established on both burners
for spark igniters to turn off.
Q347
SPARK
IGNITER
Q354 FLAME
SENSOR
BURNER
IGNITER AND
BURNER GROUND
L1
(HOT)
L2
1
2
3
1
2
3
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
ALTERNATE LIMIT CONTROLLER LOCATION.
MAXIMUM IGNITER-SENSOR CABLE LENGTH: 6 FT. (1.8 M) OR LESS.
S8702D CONTROL MODULE
ANY COMBINATION
GAS CONTROL
2.0A MAX.
TEMPERATURE
CONTOLLER
LIMIT CONTROLLER
TRANSFORMER
M16267A
SENSE 1
SENSE 2
ALARM
VALVE
GND
VALVE (GND)
24 Vac (GND)
24 Vac
BURNER
(GND)
SPARK 1
SPARK 2
Q347 SPARK
IGNITER
Q354 FLAME
SENSOR
BURNER
IGNITER AND
BURNER GROUND
3
ALARM, IF USED