Indoor Fan Rotation Check - Daikin DCG Series Service Instructions Manual

SERVICING
span length (See DRIVE BELT TENSION ADJUSTMENT
Figure). Belt tension force can be measured using a belt
tension gauge, available through most belt manufacturers.
The correct deflection force is 5 Ibs. for a new belt and 3.5 Ibs.
for a belt that has been run in. New belt tension includes initial
belt stretch.
When new V-belts are installed on a drive, the initial tension
will drop rapidly during the first few hours. Check tension
frequently during the first 24 hours of operation. Subsequent
retensioning should fall between the minimum and maximum
force. To determine the deflection distance from the normal
position, use a straightedge or stretch a cord from sheave to
sheave to use as a reference line. On multiple belt drives, an
adjacent undeflected belt can be used as a reference.
*Apply force to the center of the span.
t = Span length, inches
C = Center distance, inches
D = Larger sheave diameter, inches
d = Smaller sheave diameter, inches
h = Deflection height, inches
DRIVE BELT TENSION ADJUSTMENT
7.5 - 12.5 TON MODELS
SHEAVE
TYPE
MODEL DIAMETE
R (in)
BELT DRIVE
7.5 Ton 2.6 to 3.6 3.75 +/- 0.5 4.0 +/- 0.5 9/32 +/- 1/16
8.5 Ton 2.6 to 3.6 3.75 +/- 0.5 4.0 +/- 0.5 9/32 +/- 1/16
A, AX Standard
10 Ton 3.0 to 4.0 3.75 +/- 0.5 4.0 +/- 0.5 9/32 +/- 1/16
12.5 Ton 2.6 to 3.6 3.75 +/- 0.5 4.0 +/- 0.5 9/32 +/- 1/16
RECOMMENDED POUNDS OF FORCE PER BELT
DEFLECTION
DEFLECTION
FORCE (lbs)
(in)
Used New
S-206 INDOOR FAN ROTATION CHECK
Evaporator Fan Rotation Check (Three Phase Models
Only)
Check that fan rotates counter-clockwise when viewed from
the drive side of unit and in accordance with rotation arrow
shown on blower housing. If it does not, reverse any two
incoming power cables at Single Point Power Block. In this
case, repeat bearing check.
Do not attempt to change load side wiring. Internal wiring
assures all motors and compressors will rotate in correct
direction once evaporator fan motor rotation check has been
made.
S-207 MOTOR SHEAVE ADJUSTMENT
V , V & 2 V P
L M VP ARIABLE
The driving and driven motor sheaves should be in alignment
with each other and the shafts parallel.
V & V S A
L M HEAVES DJUSTMENT
1. Loosen set screw "B" using a 5/32" Allen key.
2. Making half or full turns from closed position, adjust
sheave pitch diameter for desired speed. DO NOT OPEN
MORE THAN SIX FULL TURNS.
3. Tighten set screw "B" securely over flat.
4. Carefully put on belts and adjust belt tension. DO NOT
FORCE BELTS OVER GROOVES.
5. Ensure all keys are in place and the set screws tight
before starting drive. Recheck set screws and belt
tension after 24 hours service.
NOTE: Future adjustments should be made by loosening
the belt tension and increasing or decreasing the pitch
diameter of the sheave by half or full turns as required.
Readjust belt tension before starting drive.
C
B
NOTE: Do not operate sheave with flange projecting
beyond the hub end.
K T M S
ITCH EY YPE OTOR
VL & VM
HEAVES
63