Related Manuals for ABB DTW
Summary of Contents for ABB DTW
- Page 1 IL 44-751-1 Instruction Leaflet Page 1 November,2001 Type DTW De-energized Tap Changer Application, Installation & Selection Guide...
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Page 2: Safety Definitions
See Figure 1 for a general view of a type DTW tap changer installation. The ability to locate the type DTW tap changer on the side of each phase coil permits very direct tap lead routing with a minimum of bends. - Page 3 Page 3 November, 2001 Figure 1: Typical installation of the type DTW tap changer All materials used in the construction of the type DTW tap changer have been chosen for their superior electrical properties, mechanical strength, temperature extremes capability, corrosion...
- Page 4 Instruction Leaflet Page 4 November, 2001 Ratings The type DTW tap changer is available in one basic current rating and is offered with several different electrostatic shielding and insulation options. Table 1 presents the various rating options. Table 1. DTW Ratings...
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Page 5: Basic Information
Construction Details and Features Basic Information The DTW, de-energized tap changer, is constructed from six major components: 1) Tap deck, 2) Worm gear set, 3) Moving contacts, 4) Stationary contacts, 5) Mounting post and 6) Drive shaft and External operating mechanism. These individual components (except number 6) are shown in Figure 3 and Figure 4. - Page 6 IL 44-751-1 Instruction Leaflet Page 6 November, 2001 Tap Deck The tap deck is a flat insulating plate. This plate serves as the base to which all of the other tap changer components are bolted. The main deck contains six through holes, which are used to bolt the tap changer to the transformer framework.
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Page 7: Driving System
IL 44-751-1 Instruction Leaflet Page 7 November, 2001 Figure 5. Moving contact Driving System The drive system consists of several parts: 1) the worm gear drive, 2) the inter-phase shafts, 3) the main drive shaft and 4) the external operating mechanism. See Figure 6. The moving contact’s steel shaft is fixed to the worm gear assembly. - Page 8 Positive mechanical stops are built into the tap changing mechanism, which will prevent turning past the lowest and highest positions. The external mechanism can be pad locked in any position (pad lock not supplied by ABB). Figure 7 shows the location of the pad-lock.
- Page 9 650 kV; the upper limit of impulse withstand in this configuration is determined by the electrical clearances designed into the transformer. Figure 8. DTW without any shielding. Figure 9. DTW with shield on tank side. Figure 10. DTW with both inner and outer shielding. NOTE: only one of the inner shields...
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Page 10: Standard Configurations
Page 10 November, 2001 Standard Configurations The type DTW tap changer is built in three standard configurations based on mounting the tap decks along the side of each phase coil. The operating mechanism may be ordered for mounting on either the left or the right hand side of the tap decks (when viewed from outside of the transformer). -
Page 11: Installation
Open shipping crate and closely examine the tap changer components for any sign of damage. • All DTW tap changers are shipped with the moving contacts in position 1. Please check to verify that the moving contacts are indeed in position 1 before continuing. Refer to Figures 14 and 15. - Page 12 Following are the steps required to properly install a DTW de-energized tap changer: 1. Remove the DTW deck from the shipping carton and verify that it is in position number 1. Note: for Left Hand Drive, the number 1 position will be as shown in figure 14 and for Right Hand Drive the number 1 position will be as shown in figure 15.
- Page 13 1 position, when connecting this shaft. 8. Mount the Drive Shaft to the DTW at the appropriate end (Left or Right) as specified on the transformer drawings. The drive shaft is assembled to the ball end fitting in the same way as the Inter-Phase Shafts.
- Page 14 Page 14 November, 2001 Figure 18. Bolt for shield not touching the gear. Figure 19. Assembly of outer and inner shielding on DTW. 12. After the drying and impregnation process of the core and coil make sure the glass fiber nuts holding the Micarta boards to the Super structure are tightened by once again.
- Page 15 14. Assemble the Connecting Tube to the ball-end fitting of the Operating mechanism the same way as the Inter-Phase Shafts were assembled to the individual DTW decks. 15. Slide the Operating Mechanism with the Connecting Tube through the mounting boss onto the Main Drive shaft.
- Page 16 ♦ To make the external connection between the Bevel Gear Housing and the Operating Mechanism assembly, an adjustable steel shaft (supplied by ABB when the Bevel Gear Housing is ordered) is used. This shaft should be pinned to both the Bevel Gear vertical shaft and to the Operating Mechanism vertical shaft.
- Page 17 Failure to do so will result in severe personal injury, property damage, or death. 20. The DTW tap changer has now been installed and should be checked for proper operation. To operate, pull out the locking pin until it disengages the Geneva Indicator Dial and turn the operating mechanism handle one complete turn.
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Page 18: Renewal Parts
(model, style, catalog number) from the unit’s nameplate. Repairs In normal use, the DTW tap changer will not require repairs. We recommend that the transformer manufacturer be contacted before any repairs are made. Maintenance ABB de-energized tap changers require little or no maintenance to ensure proper mechanical and electrical operation of the switch. - Page 19 IL 44-751-1 Instruction Leaflet Page 19 November, 2001...
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Page 20: Technical Support
SAFETY NOTATIONS CONTAINED HEREIN. In no event will ABB Inc. be responsible to the user in contract, in tort (including negligence), strict liability or otherwise for any special, indirect, incidental or consequential damage or loss whatsoever including but not limited to damage to or...