10
Operation and Maintenance Instructions
from the access door and the distribution system observed.
The diffusers are essentially non-clogging and should seldom
need cleaning or maintenance.
If the water diffusers are not functioning properly, it is a sign
that the pan or system strainer has not been working properly
and that foreign matter or dirt has accumulated in the water
distribution pipes. The nozzles can be cleared by taking a
small pointed probed and moving it rapidly back and forth in
the diffuser opening, with the pump(s) running and the cooling
load and fan(s) off.
If an extreme build-up of dirt or foreign matter occurs, remove
the end cap in each branch to flush the debris from the header
pipe. The branches or header can be removed for cleaning,
but do so only if necessary. Check the strainer in the pan to
make sure it is in good condition and positioned properly so
that cavitation or air entrainment does not occur.
All Evaporative Condensers and Closed Circuit Coolers, except
the ESW4 Closed Circuit Cooler, are supplied with ZM II
®
spray
nozzles as standard. The ZM II
®
spray nozzles do not need to
be oriented a specific way to achieve proper coil coverage.
Figure 1
shows the proper spacing of the ZM II
®
spray nozzles.
For the ESW4, wide orifice water diffusers are supplied. When
inspecting and cleaning the water distribution system, always
check that the orientation of the water diffusers is correct as
shown in
Figure 2
.
Bleed-Off Valve
The bleed-off valve, whether factory or field installed, must be
checked weekly to make sure it is functioning and set properly.
Keep the bleed-off valve wide open unless it has been
determined that it can be set partially open without causing
scaling or corrosion. Additional information can be found
under “Water Treatment and Water Chemistry”.
Pump (When Supplied)
The pump and pump motor should be lubricated and serviced
in accordance with the pump manufacturer’s instructions.
The recirculation pump should not be used as a means
of capacity control, and should not be cycled frequently.
Excessive cycling can lead to scale build-up, and reduce
wet and dry performance. On 18’ long ESW4’s supplied with
two pumps per cell, both pumps should be energized at
the same time. One pump should not be on while the other
pump is off. The pump motor shaft and impeller should be
turned by hand if the pump assembly sits idle (for a month or
more). Disconnect the power and lockout/tagout the pump
disconnect. Remove the pump motor fan guard and rotate the
pump fan/shaft several turns by hand. Reassemble the fan
guard and return to service.
Note: for the eco-ATW(E), please consult the Sage
2
and Sage
3
manual.
Coils
Contact Evapco in case of damage to the pressure vessel.
Do not affect the integrity of the pressure vessel without
approval of Evapco.
Evaporative Coil(s)
Check coil surface periodically, but at least twice a year. Inspect
the coil surface for scale and/or corrosion.
Dry Coils (optional)
Depending on outdoor conditions and unit type, the dry coil
should be inspected and cleaned at least twice a year. If the
unit is located near trees, construction, etc., the required
cleaning may be more frequent. The coil should be visually
inspected monthly along with inlet louvers and inlet screens.
The best cleaning solution for the dry coil is plain water. If the
coil has maintained and cleaned at regular intervals, water is
sufficient to remove dirt and debris from the fins. Heavy build
up on the exterior of the fins can be removed with a brush. If a
pressure washer is used, make sure the equipment is set to a
low pressure setting and that the nozzle is set to the fan spray,
not stream, otherwise damage to the fins could result.
Figure 1
- ZM II
®
Spray Nozzle Orientation.
All Coil Products except the ESW4
Figure 2
- Proper Water Diffuser Orientation
(2A Nozzles) ESW4 Models
