Mechanical Design Brian Brinson Mechanical Design Manager brian.brinson@spx.com September 26, 2018
Agenda 1. Design Process 2. Pre-Approval Drawings Bid Drawings Preliminary Drawings 3. Approval Package 4. Design Tools CAD Computer Aided Design FEA Finite Element Analysis 5. Mechanical Design Internal Design Features External Design Features Oil Preservation Systems September 26, 2018 2
Design Process
Design Process Start Cycle time varies depending on the design complexity Approval Package Order Entry Marketing & Engineering Specification Questions Electrical Design Initial BOM Electrical Checks Cooling Design Electrical Design Group Internal Design Tank Design Accessory Layout Outline Mechanical BOM Mechanical Design Group Controls Design Controls Drawings Controls BOM Controls Design Group Nameplate 90% Design Complete Design 90% Complete Submit Approval Drawings to Customer When you receive approval package 90% of engineering work is complete; detail work starts following completion of design work. September 26, 2018 4
Pre-Approval Drawings
Bid Outlines Basic layout of transformer with anticipated location of major components only (LTC, radiators, control cabinet, etc.) Should not be used for construction purposes, only to give a general idea of what the transformer will look like Dimensions provided include overall height, overall width, overall depth, shipping height, shipping width and shipping depth Bid outlines are by request only as they require engineering resources to create and may take a week to complete. September 26, 2018 6
Preliminary Outlines Show anticipated location of major components with a higher degree of accuracy than bid outlines Generally reserved for designs where the design must meet strict dimensional requirements, such as a retrofit Dimensions provided will vary depending on the need but typically include a tolerances These are by request only as they require significant engineering resources to create and may have an additional cost. September 26, 2018 7
Approval Package
Approval Package Outline Nameplate Control Wiring Accessory Drawings Typical review period for approval package is 1 week, delaying return beyond planned review period could compromise ship date. September 26, 2018 9
Outline Drawing Page 1 Special requirements should be noted at quote stage not at approvals, changes to requirements at approval stage may impact price and delivery. September 26, 2018 10
Outline Drawing Page 2 September 26, 2018 11
Things to Consider: Electronic vs. Paper Drawings Traditional Approval Package Package can consist of 12 or more sheets per set of prints That is 12-24 x 36 pieces of paper for you to look at and keep up with until they are returned, not counting small drawings Generally our order processing group will spend 1 2 days printing and preparing your package Once the drawings are printed they must be mailed to you, generally next day air Electronic Approval Package No paper Generally our order processing group can process in a few hours No shipping delays Reduce total approval submittal and return time by as much as a week Multiple people can make markups on the same print easily Easier to store at your site and easier to find if you need them If you have more than one person reviewing the prints, you will have to put all markups on one set of prints causing even more delays Consider not requiring any approval drawings, electronic or otherwise, on duplicates unless changes are requested. September 26, 2018 12
Design Tools
CAD Computer Aided Design Model Based Drawings vs. Traditional 2D Drawings Advantages: Ability to create drawings quickly Accuracy of drawing views Parametric drawing views Parametric dimensions Key items ballooned automatically Ballooned legend on drawings Allows automation of common part details Preset view orientations linked to model Sheet metal parts cut directly from models Models are modeled at 1:1 scale Ability to check fit visually September 26, 2018 14
Sample Drawing Video September 26, 2018 15
Manufacturing Documentation Model Based Shop Drawings Actual Part Parts and assemblies are detailed for plant level processes Typical Standard DWG Specification A B C BEND UP 90 D A=1.5, B=5, C=3, D=10, E=20 Example of perception problem Example of perception problem Pre-programmed drawings that reflect the standard model improve consistency and accuracy Drawing details customizable to reflect changes not pre-programmed All jobs specific parts to be made are shown true to scale, eliminating perception problems Key BOM information displayed on drawings eliminates constant cross referencing We can now utilize computers with the 3D CAD models on the shop floor to further improve visualization. September 26, 2018 16
Parametric Models Core, coils and accessory specifications from design engineers are used by the mechanical design program to build the model; utilize existing, proven mechanical design programs Model reflects proven producible designs at the plant level Contain standard pre-designed transformer options/variations Customizable to resolve conflicts or to make additions to meet customer specifications Assembled from parts which carry plant level bill of material (BOM) attributes; model drives BOM Parts contain material properties to provide assembly weights and center of gravity for customers and manufacturing September 26, 2018 17
Standard Parts Libraries Save time by modeling parts once Error reduction on purchased parts Electronic pick-list of common parts Part data associated with models SPX part number Manufacturing data Component description Weight Some suppliers already have 3D CAD models saving us from having to remodel these parts. September 26, 2018 18
Finite Element Analysis: Mechanica Utilizing our CAD models and FEA packages we can analyze our designs to establish design standards. September 26, 2018 19
Mechanical Design
Internals: Adjustable Flat Clamp Press feet Vertical Draw Rods Top Pressure Ring Bottom Yoke Band Assembly Bottom Winding Support Blocks Top Yoke Band Assembly Provides framework for stability in lifting and short circuit Secures core and coil assembly to the tank September 26, 2018 21
Low Voltage Side Internals: Adjustable Flat Clamp RV Leads HV Finish Leads RV Leads LV Finish Leads High Voltage Side RV Lead Structure RV Leads LV Start Leads Tap Leads RV Leads HV Start Leads De-energized Tap Changer Handle Copper stranded, thermally-upgraded paper insulated cables, secured for short circuit forces Insulation and clearances vary depending on the voltage The flat clamp design requires less welding on clamps and allows for smaller tank sizes compared to box beam design. September 26, 2018 22
Tank End Walls and Base Main tank weld seams welded inside and out Complete Unit Lift Lugs LTC Holddown Tank Assembly Acetal Block (cut to size at final assembly) Formed Corners (no corner welds) LTC Holddown Bar (bolted to main clamp) Jack Pads Steel base with beveled edges for skidding End Wall assemblies welded to base Non-standard base customized to meet special anchor bolt requirement September 26, 2018 23
Top Cover Core Ground Bushing Boss Ground Pads HV Bushing Boss Brace Venting Provisions PRD Mounting Boss CT Junction Box CT Mounting Provisions Cover Lift Lug Uni-hoist Non- Fall Magnetic Protection Insert Filling Flange Usually cut from single sheet of mild steel Domed cover Braced for full vacuum Machined bosses with contained gasket grooves Cover Bar Braces September 26, 2018 24
Top Cover Assembly Manhole Access HV Bushing Ground Bus PRD CT Support Plate CT Mounting Support Rod Insulation Core Ground Bushing LV Bushing CT Junction Box Bushing mounted current transformers rated per customer specifications Pre-assembled top cover welded in final assembly September 26, 2018 25
Complete Tank Assembly Radiator Vent Plug Brace Venting for Gas Space LTC LLG LTC LTI Well Pressure Switch LTC Drain Valve Control cabinet layout and wiring details completed by controls group using E3 Radiators Drain Plug Radiators ship detached Radiator valves with fully contained gasket groove LV Side Wall with Bus Duct Flange High efficiency bolt-on radiators 17 or 34 panels or custom panels Standard radiators are hot dipped galvanized, equipped with lift lugs and drain/vent plugs September 26, 2018 26
Internal Wiring Simplified representations of complete transformer for routing of cables and checking clearances Cables routed in Pro/E allow for accurate support structures, correct cable lengths with minimal waste, and enable designers to verify electrical clearances September 26, 2018 27
Assembly Sample Video September 26, 2018 28
Things to Consider: Conduit All rigid conduit vs. rigid conduit with short (<36 ) runs of flex All rigid conduit does not allow for easy installation of gauges, etc., causing a maintenance headache Rigid conduit with shorts runs of flex to gauges and fans will allow for simpler and more user friendly conduit runs SPX s standard flexible conduit is rated 60º to +150º C sunlight resistant Short runs of flex All rigid If you need all rigid conduit make sure to specify it, otherwise consider allow short runs of conduit to gauges and fans. September 26, 2018 29
Things to Consider: Seismic Do you need your transformer designed for seismic? If so which standard? Most designs that specify seismic requirements specify IEEE 693-2005 IEEE 693-2005 has three qualification levels: High Moderate Low If a customer specifies IEEE 693-2005 but does not specify the fastening method, then the transformer will be designed for a welded base, not bolted Unless specified a certified seismic report will not be supplied, the transformer will be designed to meet the required standards based on our internal design practices only Typical seismic reports can cost $10,000 or more and average 8 10 weeks for completion Sample of welded base design September 26, 2018 30
Things to consider..environmental Conditions Did you know that there are many different environmental conditions that can affect your transformer? High Altitude = Decreased dielectric strength so You need additional phase to phase spacing, additional cooling, possibly special bushings, etc. Cold Climate = Depending on the temperature, you could need Special gaskets Additional heaters in control cabinets Special controls component consideration Special consideration on oil drop Heavy Industry = Depends on the specifics of the conditions Refinery Geothermal Paper Mills = Depends on the specifics of the conditions Open Mines = Depends on the specifics of the condition Many of these conditions warrant the use of special breathers, etc., so keep in mind the more information you tell your supplier, the better! September 26, 2018 31
Oil Preservation Sealed Tank N2 Tank Conservator Tank September 26, 2018 32
Oil Preservation Systems Sealed tank design typically operates between 5 and +7.5 psig Nitrogen (inert gas) system typically operates between +0.5 and +5.0 psig Enclosed system nitrogen bottle enclosed in cabinet Open system nitrogen bottle outside of cabinet N2 generator maintains own supply of nitrogen Conservator system typically operates between 0 and +2 psig May be used with or without air cell September 26, 2018 33
Sealed Tank Pressure-Vacuum Gauge Provides indication of pressure/ vacuum inside transformer Typically range from 10 to +10 psig Can be used in conjunction with a pressure-vacuum bleeder on sealed tank designs to bleed and breathe in at pre-set levels Also used for shipping units filled with dry air or nitrogen if inert air system is not installed and activated for shipment September 26, 2018 34
Nitrogen Systems Enclosed Style Open Style Enclosed = bottle inside cabinet Open = bottle outside cabinet September 26, 2018 35
Nitrogen Systems: Generator Generates N2 on demand Eliminates need to transport and replace N2 bottles Nitrogen gas is generated as needed and stored in a tank to provide a reserve supply of nitrogen in the event of power failure Fits same footprint as standard N2 enclosure Nitrogen Purity: 99.0% to 99.5% September 26, 2018 36
Conservator System: Diagram Conservator shapes vary from round to octagonal Size is dependent on volume of oil in main tank NOTE: When installed correctly, oil surrounds the air cell, the oil level is determined by the bottom of the air cell. September 26, 2018 37
Questions? Thank you!