electrode tips are permitted to operate
while extending into the oil spray, it will
promote a carbon bridge between the
electrode tips, thus shorting out the spark
and ultimately causing ignition failure.
Clean the electrode tips and set them
properly.
7. Electrodes too close to the nozzle.
It has already been outlined that the
electrodes set too close to the nozzle will
promote spark shorting out from the
electrode tip to the nozzle, thus creating a
delayed ignition or ignition failure. Set
electrode tips according to prescribed
procedure.
8. Spark gap too wide. If the spark
gap is too wide, either there will be no
spark at all, or the spark will short out at
some other point along the ignition system.
Again, set tips as instructed previously.
However, we are learning that in many
applications today, and due to the changes
in fuel oil, a slightly wider than normal gap
may result in smoother ignition. Ignition of
fuel is not an exact science and so a couple
of settings may have to be tried to find the
best results.
9. Insulators not held securely. In the
event the electrode support bracket is loose,
or the porcelains do not fit properly in the
may move out of adjustment because of
tighten the electrode support bracket
securely, but do not overtighten because
that may crack the ceramic insulators.
10. Puffbacks may be caused by lack
of draft. If it is discovered that the ceramic
insulators are heavily sooted and/or
carbonized and the electrode tips are
properly gapped and properly set, then it is
Correcting faulty
ignition is
important.
Delayed or faulty
ignition is the
prime cause of
puffback.
9-14 Ignition Systems
junction box. If they are
loose, tighten them
securely. Also check for
loose connections at all
terminals and make sure
that wire nuts are tight.
2. Test the trans-
former. If the trans-
former is defective, replace it.
3. Loose connections at
either the secondary terminals
of the transformer, or loose
connections where the high tension leads
or buss bars are fastened to the elec-
trodes. If these connections are found to be
loose, attempt to tighten them. If this fails
to solve the problem, replace the connec-
tors. Also clean out any dust or dirt that
may have accumulated in or around the
secondary terminals of the transformer. As
previously outlined, check the high voltage
leads to determine if the insulation has
become defective.
4. Remove the porcelain insulators
from the electrode holder to determine
whether they are cracked. In many cases
the porcelains will crack beneath the clamp
of the electrode holder. Replace cracked or
crazed porcelains, even though they are still
functioning properly.
5. Carbonized insulator. Carbon
accumulations on the ceramic insulators
will conduct electricity, thus causing the
spark to short out against either the nozzle
adapter, nozzle line, or the electrode holder.
The carbon must be removed with a solvent
or cleaner. Then the insulators must be
dried and checked for cracks and/or spark
leakage. The procedure for checking for
spark leakage has been outlined.
6. Electrodes in oil spray. If the
Chapter 9
Ignition Systems