Laars MASCOT LX, Руководство по обслуживанию

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51
Mascot LX Service Manual
Spark Rod - Testing and Replacement
The spark rod should not create problems unless it
is bent for some reason. The tip of the rod should be
sharp and shiny. After long use, the tip of the rod may
be partially burnt away. This could change the clearance
between the spark and the ground rod, causing firing
problems.
1. Shut off the main power supply to the unit. Use the
switch on the front panel.
2. Turn off all gas valves connecting the unit to the
main gas supply line.
3. Remove the upper front panel.
4. Carefully disconnect the large red wire running to
the spark rod and the smaller wire running to the
ground. See Fig. B16-2.
5. Remove the two screws holding the spark rod assem-
bly in position. Now you can remove the assembly.
6. To test, lean the spark rod assembly against the top
of the combustion chamber. Reconnect the large
wire to the top of the assembly. Insert a jumper be-
tween terminals 5 and 6 on the low-voltage terminal
strip to create a “call for heat”.
Stand back and do not touch the spark rod assembly
during this test - it will carry a dangerous high voltage.
7. When you power up the boiler you should see a bright
blue spark between the spark rod and the ground rod.
This indicates that the spark rod, ground rod, SIT con-
troller, and gas pressure are all OK.
8. Power down the boiler again and check the clearance
between the spark rod and the ground rod. See Fig.
B16-3. The clearance should be 3/16” (5 mm).
9. If the assembly is damaged, replace it by reversing
the instructions listed above. Remember to remove
the jumper you installed to create the “call for heat.”
Flame Sensor - Cleaning and Replacement
Over time, the flame sensor can become tarnished or
coated. This can affect the ability of the flame sensor to
detect the flame, and eventually it will prevent the unit
from firing. This problem will happen more quickly if the
Mascot LX has been operating often at a low firing rate.
The surface of the flame sensor has a protective coating,
so it must be cleaned carefully.
Do not use sandpaper, steel wool, or emery board to
clean the flame sensor. These materials will clean the
sensor, but they will also remove the protective coating.
The sensor will work, but only for a short time.
1. Shut off the main power supply to the unit. Use the
switch on the front panel.
2. Turn off all gas valves connection the unit to the
main gas supply line.
3. Remove the upper front panel.
4. Carefully disconnect the large red wire running to the
flame sensor. See Fig. B16-1.
5. Remove the two screws holding the flame sensor
assembly in position. Now you can remove the as-
sembly.
6. The best way to clean the sensor is to use a dol-
lar bill. The paper used in the bill is just abrasive
enough to clean the sensor correctly, without remov-
ing the protective coating.
7. To reassemble, reverse the instructions listed earlier.
Be sure to insert the mounting gasket correctly.
B16
cont.
Direct Spark Ignition (continued)