VORTXô VIBRATION DAMPER

Transcription

1 VORTXô VIRTION DMPER

2 ontoured lamp Technical Support - when you need it! PLP Motion ontrol Products VORTXô Vibration Damper From the Recognized Leader in onductor Protection Much of PLP s business has developed from over 60 years of studying and analyzing the effects of wind induced conductor motion. It began in 1947 with PREFORMED rmor Rods, originally designed to protect power cables from abrasion and fatigue. PLP products are continually tested and evaluated, both in the laboratory and in the field to insure that customers have the finest product possible whether in support systems or motion control. The worldwide group of PLP companies have tested, evaluated, and offered a number of motion control designs throughout our history. Most are unique in design and offer the best conductor protection for their specific purpose. eolian Vibration ñ Its ffect on onductor eolian vibration is a high frequency, low amplitude motion caused by smooth laminar winds flowing across a cable. When conductors or cables are exposed to this wind type, a phenomenon known as vortex shedding occurs. Vortex, or eddy shedding as it is also known, creates an alternating pressure imbalance above and below the conductor, inducing it to oscillate up and down at right angles to the direction of air flow. These vibrations take the form of discrete standing waves that can cause support hardware breakdown, conductor fatigue, abrasion, and eventually conductor failure. lthough potentially very destructive, these high frequency (>5Hz), low amplitude (<1 cable diameter) standing waves are almost invisible to the naked eye and require special instrumentation to detect their severity. In terms of the frequencies observed, eolian vibration is directly related to the laminar wind velocity and is inversely related to the diameter of the cable. Thus, the higher the wind speed or the smaller diameter of wire, the higher the vibration frequency. The VORTX Vibration Damper Reduces eolian Vibration The VORTX Vibration Damper improves upon the established theory of the Stockbridge damper invented in the 1920 s. Such dampers function by transferring the conductor s vibration energy through the damper clamp to the messenger wire and weights. Inter-strand friction between wires in the messenger helps dissipate this energy as heat. In addition, these dampers work by opposing and interfering with the conductor vibration itself. The original Stockbridge Dampers were considered 2-Response designs in that they had equal weights and messenger lengths, creating 2 resonant frequencies. The VORTX Damper exceeds this 2-response performance with a multi-response design that more efficiently reduces vibration across the corresponding eolian frequency range. This is accomplished with unequal messenger lengths and weights which are matched to the specific conductor impedance and line operation conditions to achieve optimum performance. Power (W) Forced Response Test - VSD40-D efore 100 mm/sec Features Frequency (Hz) ontoured lamp luminum alloy extrusion offers a precision fit to evenly capture the conductor and uniformly distribute pressure along the conductor surface. lamp Profile During installation, the damper clamp will hang from the conductor in accordance with IE standards. Hands are free to tighten the bolt to the proper torque. Messenger Strand Precision manufactured galvanized steel messenger strand efficiently absorbs vibration energy. Weight Open galvanized ductile iron weights do not enclose the messenger, reducing the possibility of corrosion. Weight ttachment PLP s novel weight attachment system exceeds the pull-off strength requirements of the IE standards without changing the properties of the adjoining messenger. In contrast, heat from casting or welding attachment methods can alter the messenger strand and reduce performance. Features (continued) Glue compounds are avoided as these can vary in performance with changing temperature. reakaway olt Option The VORTX Vibration Damper can also be ordered with a breakaway bolt. When tightened

3 PLP Laboratory Electrical orona Testing of VORTX Damper to the recommended torque level, the top head of this bolt will shear off, ensuring that the clamp is neither over, nor undertightened. Damper Installation VORTX Dampers may be installed on either energized (hot) or unenergized (cold) lines. pplication instructions are supplied with each order which include the recommended installation procedure and bolt torque. Technical Support & Product Recommendations PLP is known worldwide for quality technical support. Our field representatives can help determine the cause and effects of wind-induced motion and help find a solution to this problem. In cases where VORTX Vibration dampers are recommended, PLP can provide the proper size, quantity, and optimal placement locations to best reduce eolian vibration. For some damper installations (such as cables incorporating fiber optics), dampers should be installed over a set of protective factory formed rods. PLP Protector Rods are offered for this purpose and combine structural reinforcement with a relatively short length. Technical ssessment The VORTX Damper was developed and tested at PLP s Engineering Facility, recognized as one of the foremost cable vibration laboratories in the world. VORTX Dampers are tested in accordance with IE 61897: Overhead Lines Requirements and Tests for Stockbridge Type eolian Vibration Dampers. This demanding test series includes energy dissipation of the damper along with mechanical, electrical, and fatigue performance. ll damper sizes meet or exceed requirements of the standard. ontact PLP for test reports that cover these results in detail. Testing and field studies continue as a service to our customers and our commitment to continuous technical improvement. The VORTX Vibration Damper Placement Software To make recommendations which maximize damping performance, PLP has developed a proprietary computer program known as the VORTX Vibration Damper Placement Software or VORTX VDP for short. This software is based upon data gathered from laboratory testing, field studies, D research, and PLP s 60+ year knowledge base on vibration. The VDP Software takes into consideration many input variables specific to the individual line, its construction, design, and local operating conditions. The software output includes the recommended damper model, quantity, and optimal placement location within the span. fter an initial testing/development phase and use by technical support, the VORTX VDP Software is now available for registration at no charge to PLP customers. Please contact your local representative or technical support for more information. Vibration Recorder To correctly find the proper VORTX Damper for your application, follow the 3 basic steps below. $#,#$#(-#'&#()*+.&!()0 VORTX DMPER atalog Number Selection: Product ode VSD "VSD VORTX (Stockbridge) Damper. 1. Select the Weight ode using the onductor Type and Diameter Weight ode (20, 25, 35, 40, 50) Ex: Damper weight for 795 kcmil 26/7 SR Drake with diameter: Select the lamp ode from the pplied Diameter lamp ode (16, 20, 25, 32, 40, 50, 61) Ex: lamp for Drake over bare conductor: 32 Ex: lamp for Drake over 0.310" diameter armor rods ( x 0.310" = 1.728" applied diameter): With the Product, Weight, and lamp ode, create the complete catalog number and confirm the damper properties. Include suffix for optional design with break-away bolt. -&%12 345*+!"#$%&&'&#()*+ Product ode VSD VORTX DMPER DETILS FOR ONDUTOR ND SHIELD WIRE PPLITIONS 1. Select Weight ode from onductor Type and Diameter 2. Select lamp ode from pplied Diameter Weight ode (wc) $#,#$#(-#'&#()*+./+!$*0 SR, SS, & L onductor Range in mm in mm OPGW Range Steel & L-lad Shield Wire Range lamp ode (cc) lamp Range (over bare cable or conductor and rods) lamp Width Inches mm Inches mm in in mm mm in in mm mm in in mm mm in mm in mm in mm

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5 FERURY 2015 VORTX ô Vibration Damper e sure to read and completely understand this procedure before applying product. e sure to select the proper PREFORMED product before installation. Product Identification VORTX VIRTION DMPER NOMENLTURE 1. lamp & Keeper: The lamp has an extruded hook shaped profile to hang onto the cable or conductor while tightening the keeper. s shown above, the lower part of the clamp is crimped onto the messenger (item 4). Together, the keeper and clamp capture the conductor to hold the damper assembly firmly onto the conductor or cable. Product identification, installation torque, and lot number are permanently etched on the clamp. 2. The bolt, washer, and lock washer are used to fasten the keeper to the clamp and secure the entire damper assembly to the cable or conductor. Washer and lock washer are necessary for proper installation. 3. Large Damper Weight: The damper design shown above has two weight sizes, this provides up to 4 resonant response frequencies (two for the large weight and two for the small weight) for more effective protection. 4. Messenger: Flexible Metal Strand 5. Small Damper Weight DESRIPTION VORTX Vibration Dampers can be clamped directly onto most aluminum based conductors including SR, R, R. PLP Protector Rods should be considered for applications on aluminum conductors with relatively soft outer aluminum strand construction such as SS. Protector rods are designed to reduce direct clamping stress on cable vulnerable to surface or core damage. This includes fiber optic cable designs such as DSS and OPGW. VORTX Vibration Dampers are classified as a Stockbridge type damper. This type of damper responds to wind induced line vibration that is characterized by high frequency, low amplitude motion also known as aeolian vibration. Stockbridge dampers have specific performance characteristics that require strategic placement on the line to counter vibration activity. Placement information shall be provided to the installer to assure that the damper will provide effective protection. This application procedure provides general instructions for damper installation and should be used in conjunction with placement information. 1

6 Supplemental placement information refers to locations,,, and D for the first four dampers as measured from the respective hardware - See figure below. Spans that require additional protection are usually considered special long span applications and may require dampers placed midspan. able ttachment hardware with multilayer rod design such as the THERMOLIGN Suspension and FIERLIGN Suspension, are exceptions as distance is measured from the outer rod ends for damper location (See Step 2). Photo 1 shows the minimum distance required from the rod ends as 50 mm (2 inches). General Placement Sequence, Dampers,,, and D placed 1st, 2nd, 3rd, and 4th respectively. RMOR-GRIP Suspension & Support NOTE: Orientation is not critical for damper performance, i.e., the large weight (or longer messenger leg) may be clamped on the cable faced toward or away from the structure. For two closely placed dampers, it may be beneficial to face the small weights (or shorter messenger legs) to avoid interference. USHION-GRIP Suspension STEP #1 PPLITION OF VORTX TM VIRTION DMPER Measure and mark the appropriate distance as given from the placement information. Placement distances are measured from attachment hardware for damper locations and (see figure above), and from dampers and for damper locations and D. See paragraph below for examples of placement from Suspensions, and for examples of placement from Dead-ends. olted lamp Suspension on are onductor olted lamp Support with rmor Rods FIERLIGN ushion lamp for OPGW Measure and mark location of Damper Suspension: When measuring from Suspension or Support hardware, distance to dampers and is measured from the center of the hardware for most applications. Examples of the measurements (labeled "" & "") are shown in figures in the next column. 2 FIERLIGN luminum Suspension for DSS Examples of damper placement from center of Suspension or Support Preformed Line Products. ll rights reserved.

7 NOTE: For SR, R, R, and Shield Wire applications, dampers may be placed directly onto the conductor, or over a single layer of armor rods. The damper clamp must be a minimum of 50 mm (2") from rmor Rod ends (on or off the rods depending on placement recommended. STEP #2 continued FIERLIGN Suspension for OPGW Example of damper placement from outer rods of Multi-layer Hardware products. Use for THERMOLIGN Suspension and FIERLIGN Suspension and FIERLIGN Dielectric Suspension. NOTE: More than one layer of rods increases the stiffness near the attachment hardware body. onsequently, the first damper is typically placed at least 50 mm or 2 inches beyond the ends of the outer layer of rods as shown in the photo below. Examples of damper placement for THERMOLIGN Dead-end and FIERLIGN Formed Wire Dead-end. Example of damper placement for FIERLIGN Dead-end (U-bolt style). STEP #3 Hang the clamp of the damper and center on the placement mark. See photo below. Photo 1: Placement of First Damper 50 mm (2 inches) from outer rods. STEP #2 When measuring from a dead-end, the distance is measured from various reference points due to the variety of designs. See Figure below. STEP #4 Tighten bolt to bring keeper against the clamp. Proper torque levels are listed in Table 1. Examples of damper placement for olted Dead-ends and ompression Dead-ends 3

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