Groth 8391B - Manual (Page 8)

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3. If any of these displays are incorrect, there is a problem with the thermocouple or the controller. If a
thermocouple signal is not input, a flashing ERR signal will be displayed in the upper right position.
5. If the thermocouple is defective, remove the thermowell assembly from the burner structure by removing (2)
1/2" U-bolts. A new thermocouple assemble can be installed or a new thermocouple can be inserted into
the thermowell. Make sure that the spring is forcing the thermocouple to contact the end of the thermowell.
Always maintain the proper polarity when connecting thermocouples. Type K (Yellow + , Red -)
ELECTRODE MAINTENANCE
[See drawing B-94961, page 16]
1. Remove the hex nut [18] and push the hex nut [16] in to pipe. Slide the shield [19] down the pipe to expose
the set spacer.
2. Remove the hex bolt and the spacer [17]. Remove the set screws in the conduit connector [8] and pull the
spark disc assembly [1,2,5,7,9,14 & 15] from the pipe. Inspect the spark disc and clean or replace as
necessary. Inspect the ceramic insulators [7] for damage. Replace if necessary.
3. Assemble as shown in drawing B-94961, then slide the complete assembly into the pipe. All connections
must be tight. Do not use Teflon tape or any other insulating material on connections.
4. Screw in set screws in conduit connector [8].
5. Install the spacer and shield over the set screw, then back the set screw out and install the locknut.
TABLE 3 - MAINTENANCE SCHEDULE
The following items should be inspected according to the schedule listed below:
COMPONENT
INSPECTION
INTERVAL
MAINTENANCE
ACTION REQUIRED
Pilot Flame 1 month
Inspect while burning to confirm that optimum flame is
achieved. Adjust air intake shutter as required.
Ignition Electrode 1 month Check electrode function. [see Electrode Maintenance]
Pilot Gas Line Filter 1 month
Record Differential Pressure and replace cartridge before
pilot supply is restricted.
Solenoid Valve
[Pilot gas shut-off]
1 month
Check solenoid function to ensure valve is opening and
closing properly
Pilot Nozzle 6 months
Inspect for deterioration due to corrosion and replace as
required.
Wiring Connections
to Electrodes
6 months Replace wire and connectors if damaged.
Pressure Switch
Dwyer 1950-20
6 months
Clean the switch and turn the vent drain plug one turn
CW, then return to standard position
Ignition Electrode 12 months
Inspect for deterioration due to corrosion & High
temperature and replace as required.
TROUBLESHOOTING
Failure to achieve Pilot Flame Ignition may be caused by:
1. Loss of AC power to panel ("POWER ON" light is off.)
2. Fuse may have burned out. [5 amp]