49
VDC signal directly. See control box label. Fan enable at
1.5 VDC.
START-UP
Before beginning any start-up operation, the start-up per-
sonnel should familiarize themselves with the unit, options and
accessories, and control sequence to understand the proper sys-
tem operation. All personnel should have a good working
knowledge of general start-up procedures and have the appro-
priate start-up and balancing guides available for consultation.
The building must be completely finished including doors,
windows, and insulation. All internal walls and doors should be
in place and in the normal position. In some cases, the interior
decorations and furniture may influence overall system perfor-
mance. The entire building should be as complete as possible
before beginning any system balancing.
Except as required during start-up and balancing operations,
no fan coil units should be operated without all the proper duct-
work attached, supply and return grilles in place, and all access
doors and panels in place and secure.
Start-up procedures vary depending on time of year (sum-
mer or winter) and building characteristics (new building/old
building, occupied/unoccupied, etc.)
Start-up in the cooling mode requires that proper care be
given to avoid condensation problems. Condensation forms on
surfaces that are colder than the dew point of the surrounding
air. If a unit is started and is piped with low-temperature chilled
water in a hot, humid atmosphere, condensation will form on
many parts of the unit. In order to avoid excessive condensa-
tion, higher temperature water should initially be used (approx-
imately 65 to 70 F) and the fan coil control set at low or medi-
um fan speed. Be sure the fan current does not exceed motor
nameplate values. Also, outside air supply fans, and bathroom
and kitchen exhaust fans should be off.
As the building temperature drops, the chilled water tem-
perature can be gradually reduced until it reaches 50 F. At this
point the outside air fans can be turned on. When the chilled
water temperature is reduced to its design point, the exhaust
fans can be turned on.
Cooling/Heating System — Prior to the water system
start-up and balancing, flush the chilled / hot water systems to
clean out dirt and debris which may have collected in the pip-
ing during construction. During the process, all unit service
valves must be in the closed position to prevent foreign matter
from entering the unit and clogging the valves and metering de-
vices. Strainers should be installed in the piping mains to pre-
vent such material from entering units during normal
operation.
During system filling, air venting from the unit is accom-
plished by the use of standard manual air vent or optional auto-
matic air venting installed on the coil. Manual air vents are ba-
sically Schrader valves. For air venting, depress the valve unit
the air has vented the coil. When water begins to escape
through the valve, release the valve. Automatic air vents may
be unscrewed one turn counterclockwise to speed initial
venting but should be screwed in for automatic venting after
start-up operation. See Fig. 42 and 43.
Air System Balancing — All duct stubs, grilles, filters,
and return-access panels must be properly installed to establish
actual system operating conditions BEFORE beginning air bal-
ancing operations.
Each individual unit and the attached ductwork is a unique
system with its own operating characteristics. For this reason,
air balancing is normally done by balance specialists who are
familiar with all procedures required to properly establish air
distribution and fan-system operating conditions. These proce-
dures should not be attempted by unqualified personnel.
Units with no ductwork have air volumes predetermined at
the factory by supply grille size and normally do not require air
balancing other than selecting the desired fan speed. Units fur-
nished with optional dampers on supply grilles may require
some small adjustments to “fine tune” the air delivery to each
grille. Opposed blade balancing dampers are not available for
all grilles on a unit with electric heat.
After proper system operation is established, the actual unit
air delivery and the actual fan motor amperage draw for each
unit should be recorded in a convenient place for future
reference.
Water System Balancing — A complete knowledge
of the hydronic system, along with its components and con-
trols, is essential to proper water system balancing. This proce-
dure should not be attempted by unqualified personnel. The
system must be complete, and all components must be in oper-
ating condition BEFORE beginning water system balancing
operations.
Each hydronic system has different operating characteristics
depending on the devices and controls used in the system. The
actual balancing technique may vary from one system to
another.
After the proper system operation is established, the appro-
priate system operating conditions such as various water tem-
peratures and flow rates should be recorded in a convenient
place for future reference.
Before and during water system balancing, conditions may
exist due to incorrect system pressures which may result in no-
ticeable water noise or undesired valve operation. After the en-
tire system is balanced, these conditions will not exist on prop-
erly designed systems.
Water Treatment — Proper water treatment is a special-
ized industry. Carrier recommends consulting an expert in this
field to analyze the water for compliance with the water quality
parameters listed in Table 6 and to specify the appropriate wa-
ter treatment regimen. The expert may recommend typical ad-
ditives such as rust inhibitors, scaling preventative, antimicro-
bial growth agents or algae preventatives. Anti-freeze solutions
may be used to lower the freezing point.
Carrier’s water coil tubes and headers are constructed of
pure copper. Multiple brass alloys may be present in the valve
package, depending on unit configuration. It is the user's re-
sponsibility to ensure the tube and piping materials furnished
by Carrier are compatible with the treated water.
CAUTION
Both of the start-up and servicing procedures described
below require the control box to be powered while adjust-
ments are made. Line voltage components are concealed
behind a secondary cover. However, installer should still
take all reasonable precautions.
Fig. 42 — Manual Air Vent
Fig. 43 — Automatic Air Vent
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