5
MPA IO&M
B51223-005
*Intake Side Shown
• 1/2-13 x 1.00 Grade 5 Hex Head Cap Screw (or equivalent)
4 required (1 in each corner)
• 1/2 Flat Washer, 8 required (2 in each corner)
• 1/2-13 Hex Nut (or equivalent), 4 required (1 in each
corner). Recommended torque setting of 18 (ft-lb)
• Split Lock Washer (or equivalent), 4 required (1 in each
corner).
A *Intake Side
A
B
(Middle connections)
*Intake Side Shown
• Intake Side Panel Connection: A series of .22” diameter
holes, 3” on center are provide to connect the front panel of
the fan assembly to the customer’s equipment. The holes
are sized for 1/4” sheet metal screws.
• All installation hardware supplied by end user.
B *Intake Side
B
Radial Gap, Overlap, and Impeller
Alignment
Efficient fan performance can be maintained by having
the correct gap and overlap between the impeller and inlet
funnel. These items should be checked at installation, after
the fan has been in operation for 24 hours, and after the unit
has been serviced.
Gap: distance between the OD of the funnel and the ID
of the impeller concentricity.
Overlap: distance the funnel and impeller overlap one
another.
This sketch shows both the gap and overlap dimensions for
all sizes.
Gap
Overlap
Gap/Overlap Dimensions
Model
Minimum
Overlap (in.)
Maximum
Overlap (in.) Minimum Gap (in.)
100
0.12
0.29
0.06
120
0.12
0.32
0.07
135
0.12
0.35
0.07
150
0.19
0.41
0.09
165
0.25
0.47
0.11
180
0.31
0.50
0.11
195
0.38
0.57
0.12
225
0.44
0.63
0.14
245
0.50
0.69
0.17
270
0.56
0.76
0.20
300
0.62
0.88
0.24
330
0.75
0.96
0.26
365
0.81
1.13
0.27
402
0.88
1.23
0.31
Gap is adjusted by loosening the inlet funnel bolts and
centering the funnel on the impeller.
Electrical Interferences Hazard:
Motor Interferences Hazard:
Never loosen the motor attachment bolts to make adjustments to the
impeller-to-funnel gap.
Overlap is adjusted by loosening the impeller hub from
the shaft and moving the impeller to the desired position
along the shaft. The transition between the inlet funnel and
impeller should be as shown; there is a smooth feel to the
profile when moving from one component to the other.
