Nortec Industries GS Series - Manual (Page 31)

· Close the shut-off valve in the water supply line
· Isolate the humidifier from the electrical power
supply at the main disconnect switch
SCALE MANAGEMENT
The gas humidifier will periodically “blowdown”
water from the tank to reduce the concentration of total
dissolved solids that accumulate during long term
operation. Gas Humidifiers are shipped factory set
with a blowdown of 25%. This setting ensures that
scale build-up will be minimized for all water
conditions.
Once the water conditions are known, the
blowdown rate can be adjusted by software (GSTC
models) or by using dip switches on the logic control
board (GSP models).
Another effective means of controlling the amount
of scale in the tank is with the use of the Full Tank
Blowdown (FTBD) built into the software. When this
feature is activated, the drain pump will be energized
to drain the entire contents of the tank and then the
tank will be refilled with fresh water, thus keeping the
amount of total dissolved solids to a minimum. The
feature can be programmed in the software to occur
after a specific amount of operating time and can also
be triggered by a signal sent to the humidifier from a
building management system.
WATER QUALITY
Due to the wide range of water conditions found
throughout North America it is important that the
blowdown is set according to the local water
conditions. By water conditions we are referring to the
hardness of the water supplied to the humidifier. The
hardness is measured in grains per gallon. It is also
important to test for silica content. Silicates may cause
foaming and contribute to scale buildup in the
humidifier tank and float chamber.
If you are unaware of the hardness or silica
content of your water supply, there are many “do it
yourself” kits which can be purchased, or there are
several companies that will perform the tests for a
reasonable price. You can even contact your
municipality for your water condition or order the
NORTEC water test kit.
Note: Water quality conditions resulting in
component failures are not covered under NORTEC’s
standard warranty.
· Silica Test: Measured in ppm (parts per million)
Follow the directions with the kit. A high reading
will decrease the performance of your system.
The recommended operating range for silica is 0
ppm to 14 ppm. Note: A high silica content along
with a high hardness content may increase the
service intervals of the system . Consult the
factory if this condition exists at the site.
· Hardness: Measured in gpg (grains per gallon).
Follow the instructions on each individually
wrapped test strip and use the colour chart
provided. The recommended operating range for
hardness is 0 gpg to 12 gpg. Note: High
hardness along with high silica may increase the
service intervals of the system. Consult the
factory if this condition exists at the site.
· pH: Follow the directions on the test strip bottle.
The recommended operating range for pH is 6.5
to 7.5 on the colour scale. Consult the factory if
outside these parameters.
· Chlorides: Measured in ppm (parts per million).
Follow the directions on the test strip bottle. The
recommended level for chlorides is not to exceed
25 ppm.
NOTE: Failure due to chloride corrosion
is not covred under Nortec’s standard warranty.
Consult factory for more information.
· High levels of chlorides will attack stainless steel.
Consult the factory for additional information if
your water contain high levels of chlorides.
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Figure #25
Site Water Test Kit P/N 1507214