Installation, Operation and Maintenance Manual
VariCool
®
VAV
17
Subject to change without notice.
10.20-IM (0818)
ELECTRICAL HAZARD
Turn OFF power and lockout service
before conducting any maintenance Keep
hands, clothing and tools clear of electrical
terminals
WARNING
Make sure to keep hands and clothing
clear of any moving belts, blowers and
motors while performing any maintenance
Failure to do so could result in death or
serious bodily injury
CAUTION
Any maintenance should be conducted
by qualified HVAC service personnel only.
Potentially hazardous situations which
may result in personal injury, equipment or
property damage
Filters
Do NOT
run unit without filters.
Throwaway filters are supplied which are pleated extended
surface type Filters should be checked monthly for dirt
accumulation and changed when necessary Replacement
filters must be the same type as originally supplied.
INFORMATION
Unit must be shut off at the disconnect
switch before the filters are serviced. Be
sure to check that the air flow direction
arrows on the filters point in the correct
direction of air flow.
Cleaning The Water-Cooled
Condenser
Any fluid that is used to carry the heat away through the
condenser contains, minerals, dust from a cooling tower or
other foreign materials Over time these contaminants will
build up on the walls of the heat exchanger
This scale or fouling will result in a reduction in water flow,
less water temperature difference between inlet and outlet,
high condensing temperature and higher fluid pressure drop.
All of these affect the operating performance and efficiency
of the system and need to be addressed
Cleaning a water-cooled condenser helps to improve the
heat transfer rate, reduce operational cost, restore efficiency,
prolong heat exchanger life and reduce pressure drop
pumping costs Deposits from water or water treatments,
such as scale, lime, rust or mud are removed
Each installation is unique. Therefore, the fluid quality and
operating conditions will dictate when the heat exchanger
needs to be cleaned
During the start-up process record the water pressure drop
across the heat exchanger Also record the inlet and outlet
water temperatures After a period of time these values can
be checked to see how much loss of operating performance
has occurred If a 10% or greater change has occurred, it
would be beneficial to clean the heat exchanger.
There are a number of commercially available products for
cleaning a heat exchanger Follow all industry practices to
safely and effectively clean the heat exchanger
Blowers
Disconnect power and lockout the service before doing any
service or maintenance
Air-cooled units are provided with adjustable belt drive
blower packages for both the evaporator and condensing
sections Check that the blower wheel is tight on the shaft
and does not contact the housing Bearings are permanently
sealed, but should be checked periodically for signs of wear
Check for restrictions or foreign material in the air circuit
The drive may be adjusted for different static pressures If
such an adjustment is made, check that the motor current
draw does not exceed the motor nameplate current by more
than 10%
Blower Motors
All blower motors are equipped with thermal overload
protectors
WARNING
Open disconnects to unit before doing
any service or maintenance A motor that
is off on thermal overload can start any
time when the automatic thermal overload
resets
Maintenance Procedures
Summary of Contents for VariCool VAV
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