Specifications

6
START-UP
Start-up procedures vary depending upon the time of year
(summer or winter) and building characteristics (new building
or old building, occupied or unoccupied, etc.).
Start-up in the Cooling mode requires that proper care be giv-
en to avoid condensation problems. Condensation forms on sur-
faces that are colder than the dew point of the surrounding air. If a
unit is started and is fed low-temperature chilled water in a hot,
humid setting, condensation will form on many parts of the unit.
In order to avoid excessive condensation, water of higher tem-
perature should be used — approximately 65 to 70 F. Also, the
building should be as completely enclosed as possible and
outside air supply fans and toilet and kitchen exhaust fans should
be off.
As the building temperature drops, the chilled water temper-
ature can gradually be 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.
Air System Balancing — All ductwork, air grilles, fil-
ters, access doors and panels must be complete and connected
to establish actual system operating conditions before air sys-
tem balancing procedures are started.
NOTE: Units are factory set for system designed operating
conditions specified at the time of order entry.
Proper belt drive alignment and tension must be maintained
when adjusting the unit fan drive speed. The drive belt tension
should not exceed
3
/
16
-in. deflection midway between the pul-
leys under 8-lb. of force. New belts tend to stretch during their
initial period of use. After 5 days of operation, check and read-
just belt tension and pulley alignment if necessary. Failure to do
so may result in excessive unit noise and/or premature belt/
bearing failure.
SERVICE
To Clean Coil
1. Brush between coil fins with a stiff wire brush. Do not
bend fins. Follow up by cleaning with a vacuum cleaner.
If coil is cleaned with an air hose, take care not to drive
dirt and dust into other components.
2. Install clean air filters.
To Check Drain — Check drain pan, drain line and trap
at start of each cooling season. A standard type pipe cleaner for
3
/
4
-in. ID pipe can ensure removal of obstructions so that con-
densate is carried away. Check the drain line at filter cleaning
time during the cooling season.
Fan and Motor Bearings — Fan shaft bearings are
permanently lubricated and sealed, and need no attention.
Check tag on motor for motor bearing lubrication instructions
(if any). Most motors furnished with these units are perma-
nently lubricated.
To Align Pulley — Loosen pulley setscrew(s). Align pul-
leys by using a straight edge as shown in Fig. 5. Retighten set-
screw(s).
To Adjust Fan Belt Tension — Loosen fan motor
base mounting screws. Reposition the motor so that belt deflec-
tion does not exceed
3
/
16
-in. at belt midpoint under 8-lb. of
force. Retighten motor mounting screws and recheck fan belt
tension.
To Clean Fan Wheel — Use a stiff brush or vacuum to
remove dirt and debris from scroll. Wipe all fan surfaces with a
damp cloth.
To Clean or Replace Air Filters — At the start of
each cooling season and after each month of operation (more
or less depending on operating conditions), replace unit filter.
To remove filter, slide filter out of filter rack from either side
of return air duct collar.
THROWAWAY OR PLEATED FILTER — Replace filter with
a good quality filter of the size shown in Table 1. Do not at-
tempt to clean and reuse a disposable filter.
Excessive Condensation on Fan Coil Unit
Parts — Excessive condensation can be caused by running
chilled water through a fan coil unit with its fan off. Therefore,
if fan cycling control is used, a water flow control valve should
be installed to shut off the water when the fan stops.
The following two practices will also help avoid condensa-
tion problems:
1. Continuous fan operation, with motorized chilled water
valve controlled by thermostat.
2. Continuous fan operation, with thermostat control to
switch fan from high to low speed (instead of switching it
off).
Motor Overload — The following are causes and reme-
dies for motor trip-out on overload:
1. Cause: Fan delivers too much air because external stat-
ic pressure is lower than the design pressure.
Remedy: Reduce fan speed by adjusting motor pulley or
changing fan shaft pulley to larger diameter.
2. Cause: Air temperature across fan motor is too high
(heating mode).
Remedy: Check ambient temperature on motor’s name-
plate. Compare to actual air temperature at the
motor or at the fan discharge. If motor’s name-
plate lists an ambient temperature of 40 C
(104 F) and the actual air temperature is higher,
either lower the air temperature or obtain a spe-
cial motor rated for high ambient temperatures.
Follow all safety considerations outlined at the beginning
of this manual.
Avoid possible injury or death. Lock open and tag electri-
cal disconnect before servicing equipment.
Fig. 5 — Fan Pulley Adjustments