By Gene Vogel
EASA Pump & Vibration Specialist
EASA’s AC Motor Verification & Redesign – Version 4 program, released in May, is an easy-to-use update to the prior Version 3, and older Version 2 program. The layout and function of the new program is mimicked from the older Version 2 program, so users can move up to the new program with an easy learning curve. Also there are features in the Version 4 program that will aid in recognizing aspects of the redesign process that can be overlooked. If you have the program running, follow along to learn about these features.
When entering a new design, the Version 4 program provides a field to identify the Customer by name and/or number. A “New” button lets the user enter customer data on the fly, but it is helpful to have the data already entered for your regular customers. The Database -> Customer menu items let you manage your Customer list ahead of time. Then customers can be easily entered by number or selected from the Customer Name dropdown list.
Use keyboard or mouse
When entering the Original Winding Data, some users prefer using the keyboard while others are more comfortable moving through the fields with the mouse. The program supports both methods. The Tab key steps through the data fields (shift-Tab for reverse). Any field with scroll arrows can be set with the Up – Down cursor key, or values can be typed in. Radio button and check boxes can be set with the Space Bar. With the mouse, just operate the scroll arrows or click in any field and type the value. Also, hover the cursor on an icon to see the icon description (see Figure 1).
When the data has been entered, the Calculate button displays a selection grid of possible redesign options. The selection grid is flexible and can be expanded to include additional columns (right click), and columns can be sorted by clicking the column heading. Several options are available to display various numbers of circuits (see Figure 2). There is a good video tutorial on using the selection grid available from the program Help or though the EASA website. Often, the choice of redesign parameters involves comparing various options. The program allows the user to select and display multiple selections from the selection grid – just hold down the CTRL key and click the desired rows. The various redesign options can then be selected with the Tabs at the bottom of the display. For a columnar comparison of critical parameters, select the Side-by-Side option from the Redesign menu.
Also, there are Round Turns buttons for Integer or Half-Turn settings just above the Calculate button on the Original Motor page. Selecting Half Turns includes those options in the selection grid. An example of half turns is 7.5 turns for a 48-slot, 4-pole machine with 12 groups of 4 which might be wound as 7-7-8-8 with a pitch of 1-11 or 7-8-7-8 with a pitch of 1-12.
Integrated rewind data
In some cases, a “bare core” design is needed when winding data may be unavailable or suspect. The EASA Motor Rewind Data – Version 4, integrated with the redesign program, can help in these cases. By finding a motor in the database with similar parameters, that winding data can be used as the basis for the bare core design. When a suitable motor is found from the database, the MotorDb -> Send to ACR menu item converts the data from that motor into a new redesign case. There is no need to re-enter the data. A video tutorial on this simple process is also available on the EASA website.
It is common to experiment with various winding parameters such as turns, pitch and connections. The best approach is to use the Calculate button to display the selection grid and choose the desired option; the resulting redesign will be opened on a new Rewind option # tab (see Figure 3). The Manual Rewind option provides an input dialog box to adjust these values. Use caution when manually redesigning windings. It is possible to enter “impossible” values such as 4 circuits with 6 poles, which the program would not ordinarily allow.
Wire size adjustments
One of the most common adjustments is wire size. A winding slot may be too full or too loose, or the chosen wire size may not be available in enough in-hand quantity. The program provides a powerful wire-size calculator to choose combinations of two wire sizes with the calculated percent change. The new wire size values from the calculator are automatically entered into the redesign with new CM/A (A/mm2) values (Figure 4).
There are a number of convenience options available in the redesign program. Core dimensions can be entered as fractions such as 3 11/16, or use simple math to convert values; 3.5 x 25.4 (convert inches to mm). On the Tools menu is an option to Set Available Wire Sizes so that only the wire sizes in your inventory appear. This list works in conjunction with the Wire Sizes Only Available checkbox on the Original Motor page just above the Calculate button. There are Default Value settings for Original Motor data. Select Motor Defaults from the Tools menu and enter whatever data you might commonly use. Common entries are hp – kW and AWG or Metric wire. Save and close the Default Motor and those values will be pre-set for new redesigns. The Reference menu has an array of simple calculators and various commonly used tables, such as Round Magnet Wire data and Three-Phase Full Load Currents. Also on the Reference menu is a PDF version of the AC Motor Redesign manual that has many of the base formulas used to calculate redesigns. The Concentric-to-Lap conversion charts are there also, which some members use for reverse conversions of Lap-to-Concentric. Contact EASA Technical Support for more information on converting to concentric windings.
Once a redesign has been calculated for an Original Motor, the Original Motor data is locked and can’t be edited without deleting the redesigns. This is to prevent a redesign being present that does not match the Original Motor. The Editor -> Allow Edits menu item has options to Delete all Redesigns or Clone Motor. Selecting Clone Motor will create a new Original Motor where the data can be edited. This is helpful for “what if” scenarios, and for multi-winding motors where most of the physical data is the same for each winding.
In the course of looking up similar motor data in the winding database and redesigning multiple motors, there may be a number of motors open at any time. The tabs at the top of the editor show the motor ID with an Icon for the type of data. When several tabs are present, right clicking any tab will display options for closing unneeded tabs: Close Others, Close Tabs to the Left, Close All.
The program Help has useful information on winding redesign in the Concepts and Tasks sections. The video tutorials available on the EASA website may also be accessed from the program Welcome screen on the Help menu. The tutorial and Help are handy resources when questions arise. Of course EASA Technical Support can also answer questions about features and functions of the program or help with redesign questions.
LEARN MORE ABOUT THIS SOFTWARE
Editor’s Note: Those who had purchased Version 3 automatically received Version 4 in May 2016. Otherwise, the program may be purchased.
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