Specifications

32
SYMPTOM: ARCING IN THE STEAM CYLINDER
An occasional arc is not a problem. When a cylinder is
restarted after a long period of off time arcing may occur
as pieces of mineral flake off the electrode surface. During
a drain cycle, arcing may occur if water is very low in the
cylinder. Arcing is a problem if it occurs frequently or if
it causes dark brown or red discoloration in the cylinder.
The dark deposits are caused by deterioration of electrode
material and must be prevented. Arcing may be caused by
several conditions:
1. Incoming water may have high conductivity.
Conductivity, the ability to conduct current, is
measured in “micromhos”. In any electrode type
humidifier there are maximum values of conduc-
tivity that may be used in the humidifier. It is very
unusual for any naturally occurring water to have
conductivity that is too high for operation. It is rec-
ommended that water conductivity be less than
900 micromhos. If water is treated by a water soft-
ener its conductivity will be higher than untreated
water. As it is boiled away its conductivity also
increases at a higher rate than untreated water.
Softened water may be too high in conductivity to
operate without arcing.
2. Drain lines within the humidifier that have become
restricted by mineral deposits prevent proper
drain rates. This causes minerals to concentrate
inside the cylinder, which in turn causes low water
levels. Low water levels cause arcing. Drain lines
should be inspected when cylinders are changed
and thoroughly cleaned if necessary.
3. A defective drain solenoid valve will prevent prop-
er draining. The solenoid should be checked to
verify that it moves freely when 24VDC is applied
to the coil. When placed in the “Drain” position,
both the drain and fill valves open and it is very
important the water level falls in the cylinder.
4. Insufficient flow of incoming fresh water will cause
arcing by causing low water levels. Since an
automatic drain is not initiated until set-point is
reached a drain will not occur if the flow rate is
too low. Therefore, if low water pressure at the
humidifier (below 20 psi) or a clogged water
strainer restricts the flow of water, arcing will
result.
5. High back pressure, which can be caused by an
obstruction in the steam hose, prevents fresh
water from entering the cylinder and results in
arcing. Care must be taken to prevent kinking of
steam hose when making bends.
6. Excessive lengths of steam hose in conjunction
with high duct static pressures cause low water
levels and arcing.
7. Frequent cleaning of the steam cylinder by
removing and flushing or by striking the side
of the cylinder potentially dislodges flakes that
can build up a “dam” in the drain lines. It is not
recommended that the cylinder be removed
except for replacement.
8. Chemicals should not be used to attempt to pre-
vent mineral build up in the cylinder or to dissolve
minerals that accumulate. Chemical treatment
may affect conductivity. Only untreated tap water
is recommended for use in the humidifier.
SYMPTOM: FOAMING
Foaming is usually due to foreign matter or impurities
getting into the cylinder through normal water supply.
Detergents, cleaning agents used to clean dirty cylinders
(Cylinders are not to be cleaned, but to be disposed of at
end of cylinder life), and water issues precipitated by very
slow or fast drain cycles. It is important to note that when
foam is generated it is as conductive as the conditioned
water and could, if circumstances are right, force a high
water level situation.
1. Clean all water lines, replace if necessary.
2. Replace cylinder.
3. Reduce softening mix or concentration.
4. Increase water volume by correcting drain
issues.
5. Changing cylinder, but with a different
electrode configuration to accommodate the
water condition.