Installation and Maintenance
EHU-600 Series Humidifiers
24
c.
Softening: Water softeners remove calcium and add sodium
which stays in solution instead of plating out. Minerals will drain
out and accumulate less.
Caution: Soft water may be more conductive and does not
allow a protective coating to form on electrodes. Because salt is
infinitely soluble in water the drainage rates required will increase
dramatically. Special EPROMs may be needed. In general avoid us-
ing softened water if conductivity is above 250
µ
mhos/cm
2
. Expect
to replace electrodes more frequently. Discontinue if any arcing
and/or foaming occurs in tank. (See Electrode Disintegration)
d.
Water Purification: If you have pure water available such as:
Deionized water, Reverse Osmosis diffusion water, or distilled
water, they can be blended with tap water or softened water to
reduce the total mineral content. Pure water alone is not con-
ductive enough to pull current. Consult your water purification
equipment vendor for proper blending equipment. Consult the
factory for recommended blend amounts. In general if blend-
ing with tap water conductivity of incoming water should be
around 200-300
µ
mhos/cm
2
. If blending with softened water
conductivity should be around 100
µ
mhos/cm
2
. Too much soft-
ened water will cause arcing and foaming in the generator. Watch
the unit closely for a few days to ensure proper operation. The
water is too pure when the "Tank Full" light comes on excessively.
e.
Magnetic Treatment: Magnetic coils designed to allow water to
be "magnetized" have been found useful, in some instances, in
reducing mineral buildup in the steam generator. The coil is
inserted in the incoming water line and may or may not be
electrically powered. Best success has been seen on well water
with high amounts of calcium dissolved in it. It's best to use
these on a trial basis at first to determine if there is a benefit
with the water being used.
4.
Electrode Disintegration/Replacement
The tank may turn black or red, arcing or flashing may be visible inside
the tank when operating. See Figure 24-1.
Electrode Disintegration: Starts generally due to poor quality water being
present in the steam generator. Poor quality water means water with high
conductivity. Because the water is highly conductive, the EHU operates
with a low water level at normal current. Low water levels mean that the
current is concentrated on a small amount of electrode surface area and
is flowing through very little water. This high amp flow/low water levels is
what usually gets arcing started, besides being very corrosive.
Electrode disintegration is most likely in the following instances:
a.
High voltage (especially 480 and 600 volts);
b.
Hard water (in excess of 20 grains/gal.);
c.
Long drain lines;
d.
Low amperage units;
e.
Any unit with a plugged drain line;
f.
Any unit with a malfunctioning drain valve;
g.
Any unit with any of the above on softened water.
Figure 24-1: Electrode Disintegration
