Appendix I - Vibration Damper Reports.pdf

APPENDIX I

Vibration Damper Reports and Details

All vibration dampers used on this project shall conform and be purchased in accordance with these specifications. Vibration damper type and placement shall conform to the following reports and details.

P.O. Box 91129 • Cleveland, Ohio 44101 l 440.461.5200 l www.preformed.com

SVD General Placement Recommendations

The following table contains the general recommendations for using PLP Spiral Vibration Dampers (SVDs):

Total Number of SVDs Recommended Per Span

Span Length (ft)

Standard Application

Standard Application With Final Tensions > 20% of RBS/UTS OR Crossing*

Span Application

Crossing* Span Application With Final

Tensions > 20% of RBS/UTS

0 – 800 2 4 6

801 – 1600 4 6 10

1601 – 2400 6 10 16

2401 – 3200 8 12 18

3201 – 4000 10 16 24

4001 – 4800 12 18 28

*For “Crossing” line applications that span water, canyons, highways, or other vibration inducing terrain.

Notes:

1. Tension values should correspond to the Average Annual Minimum Temperature or AAMT Final

Tensions.

2. SVDs may be subset together in sets of up to 3 SVDs apiece; Do not place more than 3 SVDs together in a subset as doing so may cause the SVDs to bind somewhat and reduce their overall effectiveness.

3. SVDs have the advantage of being placement independent and may be placed at either end of the span, or on both ends if so desired. However, SVDs are designed to be placed directly on the conductor or shield wire. Thus as a general recommendation, place SVDs on the bare conductor or shield wire approximately one hand’s width away from suspension rods, dead-end rods, ties, etc

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S piral V ibration D am per

Spiral Vibration Damper

1. This product may be reused if in good condition.

2. This product is intended for use by trained craftspeople only. This product SHOULD NOT BE USED by anyone who is not familiar with and trained in the use of it.

3. When working in the area of energized lines with this product, EXTRA CARE should be taken to prevent accidental electrical contact.

Damping devices are designed for the single purpose of reducing vibration. This single function is entirely different from that of protecting against (1) stress concentrations,

(2) fretting or abrasion, and (3) arc-over burning. Because of this, damping devices should be considered only as supplemental to WRAPLOCK® Tie, Armor Rod, Side Tie, Spool Tie, or other hardware at tangent supports. Dampers are also used as supplemental protection at Dead-ends.

The degree of protection needed on a specific line depends upon a number of factors such as line design, temperature, tension, exposure to wind flow, and vibration history on similar construction in the same area.

Spiral Vibration Dampers are also effective on certain size overhead shield wires and OPGW. Consult PLP® for specifics.

For damper applications on ADSS cable, refer to the FIBERLIGN® Fiber Optic Products catalog under motion control.

Consult your PREFORMED™ Sales Representative for placement and installation guidelines.

MATERIAL. The solid polyvinyl chloride helical rod material is noncorrosive and has a surface hardness which does not abrade the conductor.

GENERAL RECOMMENDATIONS

SAFETY CONSIDERATIONS

Length: Assists in identification of conductor size, corresponding to tabular information appearing on following page.

Damping Section: Helically scaled for interplay of damper and conductor, to provide the action/reaction motion that opposes the natural vibration wave.

Note: Water/Canyon Crossings – due to the increased potential of laminar wind flow, an additional 50% more dampers per span should be added to the standard rec-ommendations above for adequate protection.

In areas that are prone to high levels of vibration or conductor tension is in excess of 20% RBS, consult Preformed Line Products for specific recommendations.

NOMENCLATURE

4. For PROPER PERFORMANCE AND PERSONAL SAFETY be sure to select the proper size PREFORMED Spiral Vibration Damper before application.

5. PREFORMED Spiral Vibration Dampers are precision devices. To insure proper performance, they should be stored in cartons under cover and handled carefully.

APPLICATION-INSPECTION. The Gripping Section should be installed approximately one hand's width from the ends of Armor Rod or other hardware. It is not neces-sary to make engineering calculations as to placement.

Usage Recommendations for Spiral Vibration Dampers on Bare Conductor, Shield Wire and OPGW.

Gripping Section: Has a smaller helix designed to the grip conductor.

Span Length 0-800' 801'-1600' 1601'-2400'

Standard 2 4 6

Hi Mass 1 2 3

Number of SVDs Per Span

Thermal Rating (Continuous) 125°C

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Spiral Vibration Damper (Standard)

For use on:

Bare Conductors, Shield Wires and OPGW

Catalog Number

Diameter Range (Inches)

Units Wt./Lbs. Length (Inches)Min. Max.

5050102 .174 .249 50 29 46

5050103 .250 .326 50 31 49

5050104 .327 .461 50 34 51

5050105 .462 .563 50 36 53

5050106 .564 .760 25 50 65

EXPLANATORY NOTES:

(1) Up to three SVDs can be subset together in one location where the cable diameter is 0.461" and below.

(2) On the cables with diameters above 0.461", only two SVDs should be subset for optimal damping performance.

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Spiral Vibration Damper (Hi Mass) S piral V ibration D am per

CONSTRUCTION

The Hi Mass Spiral Vibration Damper (HMSVD) has a damping section close to double that of the standard SVD. By extending the length of the damping section, one Hi Mass SVD provides the effectiveness of two standard SVDs.

BENEFITS

• Fewer points of installation.

• Fewer components on the line.

For use on:

Bare Conductors, Shield Wires and OPGW

Catalog Number

Diameter Range (Inches)

Units Wt./Lbs. Length (Inches)Min. Max.

5050200 .250 .326 50 55 87

5050201 .327 .461 50 60 91

5050202 .462 .563 50 65 94

5050203 .564 .760 15 55 97

EXPLANATORY NOTES:

(1) Up to three SVDs can be subset together in one location where the cable diameter is 0.461" and below.

(2) On the cables with diameters above 0.461", only two SVDs should be subset for optimal damping performance.