13
Warning
Tower Start-Up
Among other sources, outbreaks of Legionnaires’ Disease have
reportedly been traced to cooling towers. Maintenance and water
treatment procedures that prevent amplification and dissemination
of Legionella and other airborne bacteria should be formulated and
implemented BEFORE systems are operated and continued regularly
thereafter to avoid the risk of sickness or death.
Water System:
1. New installations should be cleaned and treated with biocides by a water
treatment expert before startup.
2. Remove any and all accumulated debris from tower. Pay particular atten-
tion to inside areas of cold water basin, hot water basins, louvers and drift
eliminators. Make sure that cold water outlet screens are clear and properly
installed.
3. Fill the water system to an approximate depth of 7" in the depressed area
of the cold water basin at the center of the tower. For models NC8407
through NC8414 fill the water system to an approximate depth of 8". This
is the recommended operating water level. Adjust the float valve so that it is
75% open at that level. Continue filling the system until the water reaches
a level approximately
1
⁄
8
" below the lip of the overflow.
If tower is equipped with a standard case face outlet connection,
vent accumulated air from the top of the suction hood by removing
one or both tap screws provided at that location. Replace these tap
screws when venting is complete. (On certain models, the top of the
suction hood for 14" diameter side suctions is 1
1
⁄
4
" above the top of
the overflow. In those situations, it is necessary to block the overflow
and continue filling the basin to the level where the aforementioned
tap screws are submerged before venting.)
4. Completely open all hot water flow control valves. Start your pump(s) and
observe system operation. Since the water system external to the tower will
have been filled only to the level achieved in the cold water basin, a certain
amount of “pump-down” of the basin water level will occur before water
completes the circuit and begins to fall from the fill. The amount of initial
pump-down may be insufficient to cause the float valve to open. However,
you can check its operation by pressing down on the operating lever to
which the stem of the float valve is attached.
Note
installation
➠
