Mitsubishi Electric PFAV-P250VM-E Manuel D'installation page 14

(5) Perform a test run, and check that the pulley is not loose. When the test
run is completed, check the setscrew for looseness.
Note:
The fan's rotation speed must be within the operating range as shown in the
fan performance diagram. (If the fan speed goes outside the operating range,
it will trip the overcurrent relay on the fan.)
Caution:
1 The fixed disc of the pulley must be placed on the motor side.
(Do not place the sliding piece on the motor side.) See [Fig. 4.2.1].
2 After adjusting the width of the variable-width pulley, also adjust the
alignment (centering).
(Using a ruler, align the pulleys so that the width of 1 and 2 in Figure 2 is the
same.)
3 The pulley groove width in Table 1 are reference values. Adjust the PC ø
of the variable-width pulley by applying the specified number of turns.
[Fig. 4.2.1] (P.3)
A Fixed disc of the pulley
C Screw (M8) (Pointed Allen screw)
E Flat part
<A> Fixed disc must be placed on the motor side.
<B> Pulley distance
<C> Rotation direction of the pulley while in use
<D> The fixed and the sliding discs can be fixed in position relative to each other by
threading the setscrew through one of the two holes on the sliding disc so that
the tip of the setscrew rests in the V-shaped notch on either of the two flat parts
of the fixed disc.
<E> The fixed disc has threads and the sliding disc has grooves.
Table 1 Variable-width pulley PC ø table
1 Number of turns to apply
2 Pulley distance (mm)
3 PC ø of variable-width pulleys for 1.5 kW motor
4 PC ø of variable-width pulleys for 2.2 kW motor
[Fig. 4.2.2] (P.3)
A FAN side pulley
C Ruler etc.
Pulley Parallelism and Belt Tension
(1) Take the following steps to adjust the belt tension.
1 Remove the front (both top and bottom) panels.
2 Loosen the motor base fixing bolts ([Fig. 4.2.3]).
3 Adjust the belt deflection force by turning the motor base sliding bolts
to the force calculated in the next section (2).
4 Set the parallelism of the fan pulley and motor pulley so that the
contents of [Fig. 4.2.4] and Table 2 are satisfied.
5 When loosening and re-tightening the pulley securing screws to adjust
the parallelism, coat the screws with screw lock (ThreeBond 1322N or
the equivalent: procure locally) to prevent them from coming undone,
and tighten them to a torque of 13.5 N·m.
(2) Set the tension for a V-belt so that the amount of belt deflection and
deflection load meet the values specified in Table 2.
Note:
When changing the type of pulley from the standard pulley, refer to DATA
BOOK for the amount of belt deflection and deflection load.
Table 2
Power
Model
frequency
50Hz
PFAV-P250VM-E
60Hz
50Hz
PFAV-P500VM-E
60Hz
50Hz
PFAV-P750VM-E
60Hz
50Hz
PFAV-P300VM-E-F
60Hz
50Hz
PFAV-P600VM-E-F
60Hz
50Hz
PFAV-P900VM-E-F
60Hz
14
B Sliding disc
D Fixed disc of the pulley
B Variable-width pulley
Deflection Amount of
force deflection
18.0N 6.9mm
15.9N 6.8mm
28.9N 3.6mm
24.9N 3.6mm
32.4N 4.9mm
28.2N 4.9mm
12.8N 6.5mm
13.2N 6.8mm
24.2N 3.8mm
20.8N 3.8mm
19.4N 5.4mm
17.1N 5.4mm
(3) After the belt fits the pulley (after approximately 24 to 28 hours of
operation), make sure the belt is not loose, and if the belt is loose, adjust
it to an appropriate tension as described in (2). Furthermore, if the belt is
new, adjust it to approximately 1.15 times the deflection force W.
(4) After adjusting for the initial stretch in (3), readjust the tension every 2,000
hours.
[The belt life is over when the belt length has stretched by 2% including
the initial stretching of the belt (approximately 1%). (After approximately
5,000 hours of operation)]
[Fig. 4.2.3] (P.3)
A Motor base fixing bolts
[Fig. 4.2.4] (P.3)
Table 3 Pulley Parallelism
Parallelism
K (min)
Pulley
Cast-iron pulley 10 or less
[Fig. 4.2.5] (P.3) Belt Tension
<A> Deflection force W(N)
<B> L = 0.016×C C: Center distance (mm)
Tools for Adjusting Belt Tension
• To adjust the belt tension for P500-model, tools in certain size (as shown in Fig.
4.2.6/4.2.7) are required for loosening the motor base fixing bolts.
Preventing Motor from Dropping when Adjusting Belt (P500·P600-F models)
• When adjusting the belt, be sure to confirm the stopper is as shown in
[Fig. 4.2.8] before performing adjustment.
• The motor may drop out of the unit if it slides quickly toward the front of the unit.
[Fig. 4.2.6] (P.3) Extension bar
[Fig. 4.2.7] (P.3) Ratchet handle/9.5mm (3/8")
[Fig. 4.2.8] (P.3)
A Part A
<A> Detailed View of Part A
Fan bearing (P750·P900-F models)
Fan bearing needs periodical grease supply in every 2,000 hours. Supply grease
using a grease gun from a fill opening at the fan bearing. [Fig. 4.2.9]
Recommended grease: Showa Shell Sekiyu "Alvania No.3"
[Fig. 4.2.9] (P.3)
A Fill opening
B Motor base sliding bolts
Remark
Equivalent to offset of 3 mm every 1 m
B Stopper