Brochure

90
®
TensioningV-BeltDrives
General rules of tensioning.
1. Ideal tension is the lowest tension at which the belt will not slip under
peak load conditions.
2. Check tension frequently during the first 24 - 48 hours of operation.
3. Over tensioning shortens belt and bearing life.
4. Keep belts free from foreign material which may cause slip.
5. Make V-drive inspection on a periodic basis. Tension when slipping.
Never apply belt dressing as this will damage the belt and cause
early failure.
TensionMeasurementProcedure
1. Measure the belt span (see sketch).
2. Position bottom of the large o-ring on the span scale at the measured belt span.
3. Set the small o-ring on the deflection force scale to zero.
4. Place the tension checker squarely on one belt at the center of the belt span. Apply a force on the
plunger and perpendicular to the belt span until the bottom of the large o-ring is even with the top
of the next belt or with the bottom of a straight edge laid across the sheaves.
5. Remove the tension checker and read the force applied from the bottom of the small o-ring on the
deflection force scale.
6. Compare the force you have applied with the values given in Table No. 1. The force should be between
the minimum and maximum shown. The maximum value is shown for "New Belt" and new belts should
be tensioned at this value to allow for expected tension loss. Used belts should be maintained at the
minimum value as indicated in Table No.1.
Note: The ratio of deflection to belt span is 1:64.
Small Lbs.
Cross P.D.
Section Range Min. Max.
3L 1.25 - 1.75 1/2 5/8
2.00 - 2.25 5/8 7/8
2.50 - 3.00 3/4 1 1/8
4L 2.1 - 2.8 1 1/8 1 5/8
3.0 - 3.5 1 1/2 2 1/8
3.7 - 5.0 1 7/8 2 5/8
5L 3.0 - 4.2 2 2 7/8
4.5 - 5.2 2 3/8 3 3/8
The above method of tensioning belt drives is to be used when a drive has been selected in accordance with the suggestions listed in the drive selection tables of the
HVAC catalog. For drives with service factor greater than 1.5, consult Application Engineering. For exact tension calculations use the EPT EDGE
®
Selection Program.
TableNo.1SheaveDiameter-Inches  DeectionForce-Lbs
TableNo.2 FHPBelts
DeectionForce
Part Number
“Belt Tension Checker”
Small
o-ring
Force
scale
Large
o-ring
Span
scale
DEFLECTION = BELT SPAN
64
Gripbelt
®
DriveEngineeringData
Cross
Section
Smallest
Sheave
Diameter
Range
rpm
Range
Belt Deection Force
Super Gripbelt
®
Belts and
Unotched Gripbands
Gripnotch
®
Belts and
Notched Gripband Belts
Used
Belt
New
Belt
Used
Belt
New
Belt
A, AX
3.0 - 3.6
1000-2500
2501-4000
3.7
2.8
5.5
4.2
4.1
3.4
6.1
5.0
3.8 - 4.8
1000-2500
2501-4000
4.5
3.8
6.8
5.7
5.0
4.3
7.4
6.4
5.0 - 7.0
1000-2500
2501-4000
5.4
4.7
8.0
7.0
5.7
5.1
9.4
7.6
B, BX
3.4 - 4.2
860-2500
2501-4000
4.9
4.2
7.2
6.2
4.4 - 5.6
860-2500
2501-4000
5.3
4.5
7.9
6.7
7.1
7.1
10.5
9.1
5.8 - 8.6
860-2500
2501-4000
6.3
6.0
9.4
8.9
8.5
7.3
12.6
10.9
C, CX
7.0 - 9.0
500-1740
1741-3000
11.5
9.4
17.0
13.8
14.7
11.9
21.8
17.5
9.5 - 16.0
500-1740
1741-3000
14.1
12.5
21.0
18.5
15.9
14.6
23.5
21.6
D
12.0 - 16.0
200-850
851-1500
24.9
21.2
37.0
31.3
18.0 - 20.0
200-850
851-1500
30.4
25.6
45.2
38.0
3V, 3VX
2.2 - 2.4
1000-2500
2501-4000
3.3
2.9
4.9
4.3
2.65 - 3.65
1000-2500
2501-4000
3.6
3.0
5.1
4.4
4.2
3.8
6.2
5.6
4.12 - 6.90
1000-2500
2501-4000
4.9
4.4
7.3
6.6
5.3
4.9
7.9
7.3
5V, 5VX
4.4 - 6.7
500-1749
1750-3000
3001-4000
10.2
8.8
5.6
15.2
13.2
8.5
7.1 - 10.9
500-1740
1741-3000
12.7
11.2
18.9
16.7
14.8
13.7
22.1
20.1
11.8 - 16.0
500-1740
1741-3000
15.5
14.6
23.4
21.8
17.1
16.8
25.5
25.0
8V
12.5 - 17.0
200-850
851-1500
33.0
26.8
49.3
39.9
18.0 - 22.4
200-850
851 - 1500
39.6
35.3
59.2
52.7