Mitsubishi Electric PUHY-P-YJM-A Data Book page 78

• Horizontal pulley alignment and proper belt tension
1) The fan pulley and the motor pulley must be aligned to meet the criteria shown in Figure 1 and Table 1.
2) Set the tension for the V-belt so that the deflection force falls within the range as shown in the table in! !-
7.
3) After the belt has been broken in on the pulley (after 24 to 28 hours of operation), check the belt for
looseness and adjust the belt tension as specified in step (2) above as necessary. When setting the
tension for a new belt, set it to a value 1.15 times the deflection force W.
4) After the initial adjustment of the belt as described in step (3) above, readjust the belt tension every
2000 hours of operation. [The belt is due for replacement when the belt has been stretched by 2% of its
original length, including the initial stretch of 1%. (Approx. 5000 hours of operation)]
Note: Apply Screwlock (not supplied) to the retention screw on the pulley to prevent the screw from
loosening. Tighten the screw to the torque of 13.5 N·m. (Screwlock: Equivalent to ThreeBond 1322N)
(Table 1) Horizontal alignment of the pulley
Degree of parallelism
Pulley
Cast iron pulley
K
K
(Figure 1) Pulley's degree of parallelism
• Tools for Adjusting Belt Tension
To adjust the belt tension for P500-
model, tools in certain size (as shown
in Fig. 3-1/3-2) are required for
loosening the motor base fixing bolts.
• Fan bearing (P750, P900-F)
Fan bearing needs periodical grease supply in every 2000 hours. Supply grease
using a grease gun from a fill opening at the fan bearing. (Fig.4)
Recommended grease: Showa Shell Sekiyu "Alvania No.3"
K (arc-minute) Note
10 or smaller Equivalent to 3 mm
[1/8 in.] of displacement
per 1 m[3-1/4 ft]
K
K
K
C
L
(Figure 2) Belt tension
[Fig. 3-1] Extention bar
13
75
75
Belt deflection force
W(N)
C:Center distance (mm)
[Fig. 3-2] Ratchet handle/9.5mm (3/8")
190
Fill opening
Fig.4 Bearing