102777-YIM-E-0206
Unitary Products Group 63
START-UP
COMPRESSOR ROTATION
Check for proper compressor rotation (See page 114 for
symptoms of reverse compressor operations). Millennium
units are properly phased at the factory. If the blower, con-
denser 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 29, 56, 57, 65, and 66) 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
26, 27, and 28. See Table 30 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 32 and 33 for fan performance
and for pulley and drive information see Table 31.
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 26 and Table 34.
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 26 - 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.
C A U T I O N
P R O C E D U R E F O R A D J U S T I N G B E L T T E N S I O N
1 . L o o s e n f o u r b o l t s h o l d i n g m o t o r b a s e t o c h a n n e l s
2 . A d j u
s t b e l t b y t u r n i n g n u t s " A " ( s e e d e t a i l " B " ) .
3 . U s i n g a b e l t t e n s i o n c h e c k e r , a p p l y a p e r p e n d i c u l a r
f o r c e
t o o n e b e l t a t t h e m i d p o i n t o f t h e s p a n a s s h o w n . T h e d e f l e c t i o n
f o r c e s h o u l d b e a p p l i e d
u n t i l a s p e c i f i c d e f l e c t i o n d i s t a n c e
o f 1 / 6 4 " p e r i n c h o f s p a n l e n g t h i s o b t a i n e d .
4 . T o d e t e r m i n e
t h e d e f l e c t i o n d i s t a n c e f r o m n o r m a l p o s i t i o n ,
u s e a s t r a i g h t e d g e f r o m s h e a v e t o s h e a v e a s a r e f e r
e n c e l i n e .
U s e t h e r e c o m m e n d e d d e f l e c t i o n f o r c e p e r B e l t A d j u s t m e n t T a b l e .
5 . A f t e r a d j u s t i n g , r e t i
g h t e n b o l t s h o l d i n g m o t o r b a s e t o c h a n n e l .
T e n s i o n n e w b e l t s a t t h e m a x i m u m d e f l e c t i o n f o r c e
r e c o m m e n d e d . C h e c k t h e b e l t t e n s i o n a t l e a s t t w o t i m e s
d u r i n g t h e f i r s t 2 4 h r s . o f o p e r a t i o n . A n y r e - t e n s i o n i n g
s h o u l d f a l l b e t w e e n t h e m i n . a n d m a x . d e f l e c t i o n f o r c e v a l u e s .
" A "
M O T O R B A S E
D E T A I L " B "
S P A N L E N G T H
D E F L E C T I O N
F O R C E
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