Installation manual

035-16682-000-E-0303
Unitary Products Group 61
START-UP
COMPRESSOR ROTATION
Check for proper compressor rotation (See page 79 for symp-
toms of reverse compressor operations). Millennium units are
properly phased at the factory. If the blower, condenser fan,
or compressor, rotate in the wrong direction at start-up, the
electrical connection to the unit is misphased. Change the
incoming line connection phasing to obtain proper rotation.
SUPPLY AIR FAN INSTRUCTIONS
CHECK BLOWER BEARING SET SCREWS
• The bearing set screws on the supply air blower are
properly torqued before shipment. However, in transit
they may loosen. Prior to start up they should be
rechecked. The set screws are 3/8" and the torque range
is 200 - 215 in.-lbs.
NOTE: If a unit is equipped with exhaust fans, those bear-
ing set screws should also be rechecked. The set
screws are 1/4 inch and the torque range is 70 - 87
in.-lbs.
CHECKING SUPPLY AIR CFM
The RPM of the supply air blower will depend on the required
CFM, the static pressure resistances of the unit components
(Tables 26, 45, 46, 54, and 55) and the static pressure resis-
tances of both the supply and the return air duct systems.
With this information, the RPM for the supply air blower can
be determined from the blower performance data in Tables
23, 24, 24, 25, and 25. See Table 27 for pulley and drive
information for the fixed pitch pulleys supplied on the unit.
The supply air CFM must be within the limitations shown in
Table 2.
NOTE: If unit is equipped with power exhaust fans or return
air fan see Tables 26, 30, and 27 for fan perfor-
mance and for pulley and drive information see
Table 28.
FAN ROTATION
Check for proper supply air blower rotation. If fans are rotat-
ing backwards the line voltage to unit point of power connec-
tion is misphased (see Compressor Rotation above.)
NOTE: If unit is equipped with power exhaust fans or return
air fan also check them for proper rotation.
BELT TENSION
The tension on the belt should be adjusted as shown in Fig-
ure 28 and Table 31.
NOTE: If unit is equipped with power exhaust fans or return
air fan check belt tension and adjust as necessary.
AIR BALANCE
Start the supply air blower motor. Adjust the resistances in
both the supply and the return air duct systems to balance
the air distribution throughout the conditioned space. The job
specifications may require that this balancing be done by
someone other than the equipment installer.
CHECKING AIR QUANTITY
Scroll compressors require proper rotation to oper-
ate correctly. Units are properly phased at the fac-
tory. DO NOT change the internal wiring to make
the blower, condenser fans or compressor rotate
correctly.
FIGURE 28 - BELT TENSION ADJUSTMENT
On VAV and VFD units be certain all IGV’s on VAV
unit are full open, VFD drive is set to maximum
output, exhaust dampers are closed and individual
space damper boxes are full open.
VFD units with bypass must not have the bypass
activated unless all individual space dampers are
full open.
CAUTION
PROCEDURE FOR ADJUSTING BELT TENSIO N
1. Loosen four bolts holding m otor base to channels
2. A djust belt by turning nuts "A" (see detail "B ").
3. U sing a belt tension checker, apply a perpendicular force
to one belt at the m idpoint of the span as show n. The deflection
fo rc e s hould be applied until a specific deflection distance
o f 1 /6 4 " p e r in c h o f s p a n length is obtained.
4. To determ ine the deflection distance from norm al position,
u s e a s tra ig h t edge from sheave to sheave as a reference line.
U s e th e re c o m m ended deflection force per B elt A djustm ent Table.
5. A fter adjusting, retighten bolts holding m otor base to channel.
Tension new belts at the m axim um deflection force
recom m ended. C heck the belt te n s io n a t le a s t tw o tim e s
during the first 24 hrs. of operation. Any re-tensioning
should fall betw een the m in. and m ax. deflection force values.
"A "
M OTOR BASE
DETAIL "B"
SPAN LENGTH
DEFLECTIO N
F O R C E